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1.  Trends in the Supply and Distribution of Physicians in Saskatchewan: January 1962 to June 1964 
Using all the readily available sources of information, a study was designed to describe the changes in supply and distribution of physicians in Saskatchewan during the inception of the Province's controversial Medical Care Insurance Act. Baselines were obtained in January 1962, and comparisons made in June 1963 and June 1964. The physician:population ratio was 1:1037 in January 1962 and 1:980 in June 1964. The average yearly physician turnover rate of 10% was exceeded in 1960 and in 1961 and then levelled off. The levelling off continued from January 1962 to June 1963. But between June 1963 and June 1964 the total number of physicians was sufficient both to re-establish the rising trend of the previous decade and to offset some of the losses of 1960-1962.
PMCID: PMC1928160  PMID: 14275041
2.  Byssinosis: a follow-up study of workers exposed to fine grade cotton dust 
Thorax  1972;27(4):459-462.
A follow-up study was made in a group of cotton workers processing fine grade cotton fibres. Respiratory symptoms and ventilatory capacity were first recorded in 1962 and later in 1971. In 1962, 20 men and 23 women were examined whereas in 1971 only 15 of the men and 13 of the women were still in the mill. In 1962 no case of byssinosis was recorded. The prevalence of chronic cough and chronic bronchitis was higher among men than women. In 1971 the incidence of byssinosis was 20% in men and 23% in women and the prevalence of all other respiratory symptoms had also increased.
In men there was a significant mean decrease of the forced expired volume in 0·75 sec (FEV0.75) over the shift both in 1962 (P<0·05) and in 1971 (P<0·01). In women the mean acute decrease of FEV0.75 over the shift in 1962 was not statistically significant (P>0·05), but in 1971 it was (P<0·05). The mean acute reductions of FEV0·75 were considerably higher in 1971 than in 1962. In byssinotics these changes were considerably higher than in non-byssinotics. The chronic effect on ventilatory capacity of exposure to fine cotton dust was not observed in this study.
PMCID: PMC469951  PMID: 5075616
3.  Susceptibility of N. gonorrhoeae to Antibiotics 
Gonorrhea has increased in incidence over the past five years in Manitoba as elsewhere. Cases which did not respond to routine penicillin treatment were noted to be occuring more often. In 1948, strains of N. gonorrhoeae isolated in Canada were all sensitive to 0.06 unit of penicillin per c.c. in vitro. Commencing in May 1962, strains of N. gonorrhoeae were isolated from 100 patients of each sex attending the clinic at the St. Boniface General Hospital. Eighteen per cent required concentrations of more than 0.05 unit of penicillin per ml. to inhibit growth; 31% were not inhibited by the 2 μg. disc of dihydrostreptomycin; but only one strain was found resistant to sulfisoxazole and none to oxytetracycline. Results of penicillin treatment were markedly less successful in the patients with strains that demonstrated reduced penicillin sensitivity. Use of streptomycin and a sulfonamide proved to be a satisfactory substitute. Intramuscular oxytetracycline was less successful despite the laboratory findings.
PMCID: PMC1921705  PMID: 14063939
4.  Antimicrobial susceptibility/resistance and genetic characteristics of Neisseria gonorrhoeae isolates from Poland, 2010-2012 
In Poland, gonorrhoea has been a mandatorily reported infection since 1948, however, the reported incidences are likely underestimated. No antimicrobial resistance (AMR) data for Neisseria gonorrhoeae has been internationally reported in nearly four decades, and data concerning genetic characteristics of N. gonorrhoeae are totally lacking. The aims of this study were to investigate the AMR to previously and currently recommended gonorrhoea treatment options, the main genetic resistance determinant (penA) for extended-spectrum cephalosporins (ESCs), and genotypic distribution of N. gonorrhoeae isolates in Poland in 2010-2012.
N. gonorrhoeae isolates cultured in 2010 (n = 28), 2011 (n = 92) and 2012 (n = 108) in Warsaw and Bialystok, Poland, were examined using antimicrobial susceptibility testing (Etest), pyrosequencing of penA and N. gonorrhoeae multi-antigen sequence typing (NG-MAST).
The proportions of N. gonorrhoeae isolates showing resistance were as follows: ciprofloxacin 61%, tetracycline 43%, penicillin G 22%, and azithromycin 8.8%. No isolates resistant to ceftriaxone, cefixime or spectinomycin were found. However, the proportion of isolates with an ESC MIC = 0.125 mg/L, i.e. at the resistance breakpoint, increased significantly from none in 2010 to 9.3% and 19% in 2012 for ceftriaxone and cefixime, respectively. Furthermore, 3.1% of the isolates showed multidrug resistance, i.e., resistance to ciprofloxacin, penicillin G, azithromycin, and decreased susceptibility to cefixime (MIC = 0.125 mg/L). Seventy-six isolates (33%) possessed a penA mosaic allele and 14 isolates (6.1%) contained an A501V/T alteration in penicillin-binding protein 2. NG-MAST ST1407 (n = 58, 25% of isolates) was the most prevalent ST, which significantly increased from 2010 (n = 0) to 2012 (n = 46; 43%).
In Poland, the diversified gonococcal population displayed a high resistance to most antimicrobials internationally previously recommended for gonorrhoea treatment and decreasing susceptibility to the currently recommended ESCs. The decreasing susceptibility to ESCs was mostly due to the introduction of the internationally spread multidrug-resistant NG-MAST ST1407 in 2011. It is essential to promptly revise the gonorrhoea treatment guidelines, improve the gonorrhoea laboratory diagnostics, and implement quality assured surveillance of gonococcal AMR (ideally also treatment failures) in Poland.
PMCID: PMC3922028  PMID: 24502606
Neisseria gonorrhoeae; Gonorrhoea; Poland; Antimicrobial resistance (AMR); Extended-spectrum cephalosporins (ESCs); Ceftriaxone; Cefixime; penA; NG-MAST
5.  Moderately and Heavily Used Biomedical Journals * 
The purpose of this investigation was to produce a title list of current journals supplying upwards of 75 percent of demand at the Columbia and Yale Medical Libraries. Columbia received nearly 2,000 journals and Yale over 1,500; findings are based upon an analysis of canceled charge slips for issues published from 1959 through June 1962. This combined study of recorded usage for six months in the Columbia Medical Library (12.9 percent of circulation during January through June 1962) and for one year in the Yale Medical Library (12.5 percent of 1961/62 circulation) revealed that a core of 262 journals supplied 80 percent of use of titles published in the 1959 to mid-1962 period. However, it is probable that current issues of all titles received were used at least once within the libraries. Titles of sixty-seven journals which supplied slightly more than 50 percent of use are listed.
PMCID: PMC198101  PMID: 14119296
6.  Phenotypic and genetic characterisation of bacterial sexually transmitted infections in Bissau, Guinea-Bissau, West Africa: a prospective cohort study 
BMJ Open  2012;2(2):e000636.
Knowledge regarding characteristics and transmission of Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium and antibiotic resistance in N gonorrhoeae in Guinea-Bissau, West Africa, is entirely lacking.
To characterise N gonorrhoeae, C trachomatis and M genitalium samples from Guinea-Bissau and to define bacterial populations, possible transmission chains and for N gonorrhoeae spread of antibiotic-resistant isolates.
Prospective cohort study.
Two sexual health and family planning clinics, Bissau, Guinea-Bissau.
Positive samples from 711 women and 27 men.
Material and methods
Positive samples for N gonorrhoeae (n=31), C trachomatis (n=60) and M genitalium (n=30) were examined. The gonococcal isolates were characterised with antibiograms, serovar determination and N gonorrhoeae multiantigen sequence typing (NG-MAST). The C trachomatis ompA gene and the M genitalium mgpB gene were sequenced, and phylogenetic analyses were performed.
For N gonorrhoeae, the levels of resistance (intermediate susceptibility) to ciprofloxacin, erythromycin, rifampicin, ampicillin, tetracycline, penicillin G and cefuroxime were 10% (0%), 6% (10%), 13% (10%), 68% (0%), 74% (0%), 68% (16%) and 0% (84%), respectively. All isolates were susceptible to cefixime, ceftriaxone, spectinomycin and azithromycin, and the minimum inhibitory concentrations of kanamycin (range: 8–32 mg/l) and gentamicin (range: 0.75–6 mg/l) were low (no resistance breakpoints exist for these antimicrobials). 19 NG-MAST sequence types (STs) (84% novel STs) were identified. Phylogenetic analysis of the C trachomatis ompA gene revealed genovar G as most prevalent (37%), followed by genovar D (19%). 23 mgpB STs were found among the M genitalium isolates, and 67% of isolates had unique STs.
The diversity among the sexually transmitted infection (STI) pathogens may be associated with suboptimal diagnostics, contact tracing, case reporting and epidemiological surveillance. In Guinea-Bissau, additional STI studies are vital to estimate the STI burden and form the basis for a national sexual health strategy for prevention, diagnosis and surveillance of STIs.
Article summary
Article focus
Knowledge regarding characteristics and transmission of Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium and antibiotic resistance in N gonorrhoeae in Guinea-Bissau, West Africa, is entirely lacking.
We aimed to phenotypically and genetically characterise N gonorrhoeae, and genetically characterise C trachomatis and M genitalium samples from women attending two sexual health clinics in Bissau, Guinea-Bissau and to define the bacterial populations, possible transmission chains and for N gonorrhoeae also to define the presence and spread of antibiotic-resistant isolates from women and additionally a group of symptomatic men.
Key messages
In Guinea-Bissau, N gonorrhoeae isolates displayed high level of resistance to traditional gonorrhoea antimicrobials but have remained susceptible to extended-spectrum cephalosporins, spectinomycin and azithromycin.
Genovar G, D and F were the most prevalent C trachomatis genovars, the usually most common genovar among heterosexuals, that is, genovar E, was rare.
The diversity among the bacterial STI pathogens may be associated with suboptimal diagnostics, contact tracing, case reporting and epidemiological surveillance. Additional studies are vital to estimate the STI burden and form the basis for a national sexual health strategy for prevention, diagnosis and surveillance.
Strengths and limitations of this study
This is the first time N gonorrhoeae, C trachomatis and M genitalium samples from Bissau, Guinea-Bissau, have been phenotypically and genetically characterised to define the bacterial populations, possible transmission chains and antibiotic resistance in N gonorrhoeae.
The study sample was relatively small, and in this setting, it is difficult to perform appropriate sample transportation and storage, as well as optimised diagnostics, which may have resulted in that true-positive samples were lost.
PMCID: PMC3329603  PMID: 22436137
7.  Treating genitourinary and pharyngeal gonorrhoea with single dose ceftriaxone. 
Genitourinary Medicine  1989;65(1):14-17.
The efficacy of ceftriaxone 250 mg given as a single intramuscular dose to treat genitourinary and pharyngeal gonorrhoea is compared with the outcome of the Danish standard treatment for uncomplicated genitourinary gonorrhoea, pivampicillin 1.4 g and probenecid 1 g, both given by mouth. The study comprised 327 patients for whom the diagnosis of gonorrhoea was made by microscopy of a methylene blue stained smear at their first visit to the clinic and for whom the diagnosis was later confirmed by culture of Neisseria gonorrhoeae. One hundred and seventy patients with genitourinary gonorrhoea (18 with and 152 without concomitant pharyngeal infection) were treated with ceftriaxone. One hundred and fifty seven (17 with and 140 without concomitant pharyngeal infection) were treated with pivampicillin. One week after treatment N gonorrhoeae was isolated from none of 18, 1/152, (1%), 11/17 (65%), and 6/140 (4%) patients, respectively. At a second attendance two weeks after treatment no further treatment failure was found. During the study period, a further 52 patients with pharyngeal infection (with or without concomitant genitourinary infection) that was shown by culture only were treated with a single intramuscular injection of 250 mg ceftriaxone. No treatment failure was observed in this group. Only minor adverse drug reactions were seen. Ceftriaxone 250 mg as a single intramuscular injection is therefore safe and effective in treating gonorrhoea, including pharyngeal infection.
PMCID: PMC1196180  PMID: 2921047
8.  Monitoring Antimicrobial Susceptibility of Neisseria gonorrhoeae Isolated from Bangladesh during 1997-2006: Emergence and Pattern of Drug-resistant Isolates 
Gonorrhoea is one of the most common sexually transmitted infections (STIs) in developing countries, and the emergence of resistance to antimicrobial agents in Neisseria gonorrhoeae is a major obstacle in the control of gonorrhoea. Periodical monitoring of antimicrobial susceptibility of N. gonorrhoeae is essential for the early detection of emergence of drug resistance. In total, 1,767 gonococcal strains isolated from males and females (general population and those with high-risk behaviour) from different parts of Bangladesh were studied during 1997-2006. Minimum inhibitory concentrations of penicillin, tetracycline, ciprofloxacin, ceftriaxone, spectinomycin, and azithromycin for the isolates were determined by the agar dilution method. Isolates resistant to three or more antimicrobial agents are considered multidrug-resistant. The prevalence of plasmid-mediated penicillinase-producing N. gonorrhoeae (PPNG) and plasmid-mediated tetracycline-resistant N. gonorrhoeae (TRNG) was determined. Nine percent of the isolates were resistant to ciprofloxacin in 1997 compared to 87% in 2006. Multidrug-resistant N. gonorrhoeae have emerged in 1997, and 44% of the strains (n=66) isolated during 2006 were multidrug-resistant. Forty-two percent of the isolates in 2006 were both PPNG- and TRNG-positive compared to none in 1997. The rapidly-changing pattern of gonococcal antimicrobial susceptibility warrants the need for an antimicrobial susceptibility-monitoring programme, and periodical analysis and dissemination of susceptibility data are essential to guide clinicians and for successful STI/HIV intervention programmes.
PMCID: PMC2963766  PMID: 20941895
Drug resistance, Microbial; Gonorrhoea; Neisseria gonorrhoeae; Sexually transmitted infections; Surveillance; Bangladesh
9.  Neisseria gonorrhoeae Induces a Tolerogenic Phenotype in Macrophages to Modulate Host Immunity 
Mediators of Inflammation  2013;2013:127017.
Neisseria gonorrhoeae is the etiological agent of gonorrhoea, which is a sexually transmitted disease widespread throughout the world. N. gonorrhoeae does not improve immune response in patients with reinfection, suggesting that gonococcus displays several mechanisms to evade immune response and survive in the host. N. gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and dendritic cells. In this study, we determined whether N. gonorrhoeae directly conditions the phenotype of RAW 264.7 murine macrophage cell line and its response. We established that gonococcus was effectively phagocytosed by the RAW 264.7 cells and upregulates production of immunoregulatory cytokines (IL-10 and TGF-β1) but not the production of proinflammatory cytokine TNF-α, indicating that gonococcus induces a shift towards anti-inflammatory cytokine production. Moreover, N. gonorrhoeae did not induce significant upregulation of costimulatory CD86 and MHC class II molecules. We also showed that N. gonorrhoeae infected macrophage cell line fails to elicit proliferative CD4+ response. This implies that macrophage that can phagocytose gonococcus do not display proper antigen-presenting functions. These results indicate that N. gonorrhoeae induces a tolerogenic phenotype in antigen-presenting cells, which seems to be one of the mechanisms to induce evasion of immune response.
PMCID: PMC3800590  PMID: 24204097
10.  Chlamydial and gonococcal reinfection among men: a systematic review of data to evaluate the need for retesting 
Sexually Transmitted Infections  2006;83(4):304-309.
This study aimed to systematically review and describe the evidence on chlamydia and gonorrhoea reinfection among men, and to evaluate the need for retesting recommendations in men. PubMed and STI conference abstract books from January 1995 to October 2006 were searched to identify studies on chlamydia and gonorrhoea reinfection among men using chlamydia and gonorrhoea nucleic acid amplification tests or gonorrhoea culture. Studies were categorised as using either active or passive follow‐up methods. The proportions of chlamydial and gonococcal reinfection among men were calculated for each study and summary medians were reported. Repeat chlamydia infection among men had a median reinfection probability of 11.3%. Repeat gonorrhoea infection among men had a median reinfection probability of 7.0%. Studies with active follow‐up had moderate rates of chlamydia and gonorrhoea reinfection among men, with respective medians of 10.9% and 7.0%. Studies with passive follow‐up had higher proportions of both chlamydia and gonorrhoea reinfections among men, with respective medians of 17.4% and 8.5%. Proportions of chlamydia and gonorrhoea reinfection among men were comparable with those among women. Reinfection among men was strongly associated with previous history of sexually transmitted diseases and younger age, and inconsistently associated with risky sexual behaviour. Substantial repeat chlamydia and gonorrhoea infection rates were found in men comparable with those in women. Retesting recommendations in men are appropriate, given the high rate of reinfection. To optimise retesting guidelines, further research to determine effective retesting methods and establish factors associated with reinfection among men is suggested.
PMCID: PMC2598678  PMID: 17166889
11.  Reducing the risk of gonorrhoea in black Caribbean men: can we identify risk factors? 
Sexually Transmitted Infections  2003;79(2):119-123.
Objectives: Grouping patients by self assigned ethnicity may hide intraethnic differences in disease associations and sexual behaviour patterns. The aim of the study was to detect associations between gonorrhoea with differences in ancestry, degree of acculturation, and religious belief in young black Caribbean men, which could subsequently be used to target health promotion interventions.
Methods: A questionnaire based case-control study of black Caribbean men with gonorrhoea and a community control group without gonorrhoea.
Results: A lesser degree of acculturation, attending a single sex school, increasing numbers of partners, lack of condom use, not being married, and a belief that sex before marriage was not wrong were associated with an increased risk of gonorrhoea. Country of birth and religious belief were not associated with gonorrhoea.
Conclusions: A number of factors were identified which may be useful in designing healthcare interventions in young black Caribbean men and these differed little from those in other ethnic groups. The healthcare intervention should include advice on reducing the number of partners and increasing the use of condoms.
PMCID: PMC1744632  PMID: 12690132
12.  Biofilm Formation by Neisseria gonorrhoeae  
Infection and Immunity  2005;73(4):1964-1970.
Studies were performed in continuous-flow chambers to determine whether Neisseria gonorrhoeae could form a biofilm. Under these growth conditions, N. gonorrhoeae formed a biofilm with or without the addition of 10 μM sodium nitrite to the perfusion medium. Microscopic analysis of a 4-day growth of N. gonorrhoeae strain 1291 revealed evidence of a biofilm with organisms embedded in matrix, which was interlaced with water channels. N. gonorrhoeae strains MS11 and FA1090 were found to also form biofilms under the same growth conditions. Cryofield emission scanning electron microscopy and transmission electron microscopy confirmed that organisms were embedded in a continuous matrix with membranous structures spanning the biofilm. These studies also demonstrated that N. gonorrhoeae has the capability to form a matrix in the presence and absence of CMP-N-acetylneuraminic acid (CMP-Neu5Ac). Studies with monoclonal antibody 6B4 and the lectins soy bean agglutinin and Maackia amurensis indicated that the predominate terminal sugars in the biofilm matrix formed a lactosamine when the biofilm was grown in the absence of CMP-Neu5Ac and sialyllactosamine in the presence of CMP-Neu5Ac. N. gonorrhoeae strain 1291 formed a biofilm on primary urethral epithelial cells and cervical cells in culture without loss of viability of the epithelial cell layer. Our studies demonstrated that N. gonorrhoeae can form biofilms in continuous-flow chambers and on living cells. Studies of these biofilms may have implications for understanding asymptomatic gonococcal infection.
PMCID: PMC1087446  PMID: 15784536
13.  Neisseria gonorrhoeae Infection Protects Human Endocervical Epithelial Cells from Apoptosis via Expression of Host Antiapoptotic Proteins▿ † 
Infection and Immunity  2009;77(9):3602-3610.
Several microbial pathogens can modulate the host apoptotic response to infection, which may contribute to immune evasion. Various studies have reported that infection with the sexually transmitted disease pathogen Neisseria gonorrhoeae can either inhibit or induce apoptosis. N. gonorrhoeae infection initiates at the mucosal epithelium, and in women, cells from the ectocervix and endocervix are among the first host cells encountered by this pathogen. In this study, we defined the antiapoptotic effect of N. gonorrhoeae infection in human endocervical epithelial cells (End/E6E7 cells). We first established that N. gonorrhoeae strain FA1090B failed to induce cell death in End/E6E7 cells. Subsequently, we demonstrated that stimulation with N. gonorrhoeae protected these cells from staurosporine (STS)-induced apoptosis. Importantly, only End/E6E7 cells incubated with live bacteria and in direct association with N. gonorrhoeae were protected from STS-induced apoptosis, while heat-killed and antibiotic-killed bacteria failed to induce protection. Stimulation of End/E6E7 cells with live N. gonorrhoeae induced NF-κB activation and resulted in increased gene expression of the NF-κB-regulated antiapoptotic genes bfl-1, cIAP-2, and c-FLIP. Furthermore, cIAP-2 protein levels also increased in End/E6E7 cells incubated with gonococci. Collectively, our results indicate that the antiapoptotic effect of N. gonorrhoeae in human endocervical epithelial cells results from live infection via expression of host antiapoptotic proteins. Securing an intracellular niche through the inhibition of apoptosis may be an important mechanism utilized by N. gonorrhoeae for microbial survival and immune evasion in cervical epithelial cells.
PMCID: PMC2738021  PMID: 19546192
14.  A bacterial PriB with weak single-stranded DNA binding activity can stimulate the DNA unwinding activity of its cognate PriA helicase 
BMC Microbiology  2011;11:189.
Bacterial DNA replication restart pathways facilitate reinitiation of DNA replication following disruptive encounters of a replisome with DNA damage, thereby allowing complete and faithful duplication of the genome. In Neisseria gonorrhoeae, the primosome proteins that catalyze DNA replication restart differ from the well-studied primosome proteins of E. coli with respect to the number of proteins involved and the affinities of their physical interactions: the PriA:PriB interaction is weak in E. coli, but strong in N. gonorrhoeae, and the PriB:DNA interaction is strong in E. coli, but weak in N. gonorrhoeae. In this study, we investigated the functional consequences of this affinity reversal.
We report that N. gonorrhoeae PriA's DNA binding and unwinding activities are similar to those of E. coli PriA, and N. gonorrhoeae PriA's helicase activity is stimulated by its cognate PriB, as it is in E. coli. This finding is significant because N. gonorrhoeae PriB's single-stranded DNA binding activity is weak relative to that of E. coli PriB, and in E. coli, PriB's single-stranded DNA binding activity is important for PriB stimulation of PriA helicase. Furthermore, a N. gonorrhoeae PriB variant defective for binding single-stranded DNA can stimulate PriA's helicase activity, suggesting that DNA binding by PriB might not be important for PriB stimulation of PriA helicase in N. gonorrhoeae. We also demonstrate that N. gonorrhoeae PriB stimulates ATP hydrolysis catalyzed by its cognate PriA. This activity of PriB has not been observed in E. coli, and could be important for PriB stimulation of PriA helicase in N. gonorrhoeae.
The results of this study demonstrate that a bacterial PriB homolog with weak single-stranded DNA binding activity can stimulate the DNA unwinding activity of its cognate PriA helicase. While it remains unclear if N. gonorrhoeae PriB's weak DNA binding activity is required for PriB stimulation of PriA helicase, the ability of PriB to stimulate PriA-catalyzed ATP hydrolysis could play an important role. Thus, the weak interaction between N. gonorrhoeae PriB and DNA might be compensated for by the strong interaction between PriB and PriA, which could result in allosteric activation of PriA's ATPase activity.
PMCID: PMC3179954  PMID: 21861872
15.  Neisseria gonorrhoeae non-susceptible to cephalosporins and quinolones in Northwest Ethiopia 
BMC Infectious Diseases  2013;13:415.
The occurrence of antibiotic resistant Neisseria gonorrhoeae isolates is a serious public health problem in different corners of the globe. The objective of this study was to analyze the antimicrobial susceptibility pattern of N. gonorrhoeae in Northwest Ethiopia.
This was a retrospective study of N. gonorrhoeae isolated from genital swabs of patients referred to the Amhara Regional Health Research Laboratory between September 2006 and June 2012 in Bahir Dar, Ethiopia. A structured check list was used to collect socio-demographic and laboratory variables. Data were analyzed using SPSS software version 16.
Out of 352 genital specimens processed, 29 clinical strains of N. gonorrhoeae were identified. The percentage of N. gonorrhoeae isolates non-susceptible to ceftriaxone, ciprofloxacin, tetracycline and penicillin G was 27.8%, 40.9%, 92.6% and 94.4% respectively. Twenty percent of the isolates were found to be non-susceptible to both ceftriaxone and ciprofloxacin. Non-susceptibility to an injectable cephalosporin and any two of quinolones, penicillins or tetracyclines was observed in 27.8% of the isolates. The percentage of N. gonorrhoeae which were non-susceptible to tetracycline or penicillin G was high throughout the study period. However, the percentage of fluoroquinolone or cephalosporine non-susceptible strains showed an increasing trend.
A high percentage of N. gonorrhoeae isolated from genital specimens in Northwest Ethiopia are non-susceptible to an injectable cephalosporin and any two of quinolones, penicillins or tetracyclines. Treatment of gonorrhea in the study area needs to be guided by antibiotic susceptibility testing of isolates.
PMCID: PMC3844457  PMID: 24007340
Non-susceptible; Neisseria gonorrhoeae; Ethiopia
16.  The Neisseria Lipooligosaccharide-Specific α-2,3-Sialyltransferase Is a Surface-Exposed Outer Membrane Protein  
Infection and Immunity  2002;70(7):3744-3751.
Neisseria gonorrhoeae and Neisseria meningitidis express an ∼43-kDa α-2,3-sialyltransferase (Lst) that sialylates the surface lipooligosaccharide (LOS) by using exogenous (in all N. gonorrhoeae strains and some N. meningitidis serogroups) or endogenous (in other N. meningitidis serogroups) sources of 5′-cytidinemonophospho-N-acetylneuraminic acid (CMP-NANA). Sialylation of LOS can protect N. gonorrhoeae and N. meningitidis from complement-mediated serum killing and from phagocytic killing by neutrophils. The precise subcellular location of Lst has not been determined. We confirm and extend previous studies by demonstrating that Lst is located in the outer membrane and is surface exposed in both N. gonorrhoeae and N. meningitidis. Western immunoblot analysis of subcellular fractions of N. gonorrhoeae strain F62 and N. meningitidis strain MC58⊄3 (an acapsulate serogroup B strain) performed with rabbit antiserum raised against recombinant Lst revealed an ∼43-kDa protein exclusively in outer membrane preparations of both pathogens. Inner membrane, periplasmic, cytoplasmic, and culture supernatant fractions were devoid of Lst, as determined by Western blot analysis. Consistent with this finding, outer membrane fractions of N. gonorrhoeae were significantly enriched for sialyltransferase enzymatic activity. A trace of enzymatic activity was detected in inner membrane fractions, which may have represented Lst in transit to the outer membrane or may have represented inner membrane contamination of outer membrane preparations. Subcellular preparations of an isogenic lst insertion knockout mutant of N. gonorrhoeae F62 (strain ST01) expressed neither a 43-kDa immunoreactive protein nor sialyltransferase activity. Anti-Lst rabbit antiserum bound to whole cells of N. meningitidis MC58⊄3 and wild-type N. gonorrhoeae F62 but not to the Lst mutant ST01, indicating the surface exposure of the enzyme. Although the anti-Lst antiserum avidly bound enzymatically active, recombinant Lst, it inhibited Lst (sialyltransferase) activity by only about 50% at the highest concentration of antibody used. On the contrary, anti-Lst antiserum did not inhibit sialylation of whole N. gonorrhoeae cells in the presence of exogenous CMP-NANA, suggesting that the antibody did not bind to or could not access the enzyme active site on the surface of viable Neisseria cells. Taken together, these results indicate that Lst is an outer membrane, surface-exposed glycosyltransferase. To our knowledge, this is the first demonstration of the localization of a bacterial glycosyltransferase to the outer membrane of gram-negative bacteria.
PMCID: PMC128106  PMID: 12065517
17.  Binding of Progesterone to Neisseria gonorrhoeae and Other Gram-Negative Bacteria 
Infection and Immunity  1977;16(1):115-123.
The binding of [1,2-3H]progesterone to progesterone-sensitive Neisseria gonorrhoeae CS-7 and the progesterone-insensitive Neisseria mucosa, Pseudomonas aeruginosa, and Salmonella typhimurium (rough and smooth strains) was investigated. The kinetics of binding to N. gonorrhoeae CS-7 demonstrated that the majority of the progesterone binding occurred and equilibrium was reached within the first 30 min. Despite the rapid binding of progesterone, only about 20% of the added steroid was bound at the cell concentration used throughout this study. Whole cells of progesterone-insensitive bacteria bound progesterone less efficiently than the progesterone-sensitive N. gonorrhoeae CS-7. N. mucosa bound low amounts of this steroid (20% of that bound by N. gonorrhoeae CS-7) whereas the other gram-negative bacteria exhibited little progesterone binding (<3% of that bound by N. gonorrhoeae CS-7). The outer membrane permeability of N. gonorrhoeae CS-7, as measured by crystal violet uptake and inhibition, was similar to the deep rough mutant of S. typhimurium TA 1535. The latter organism neither bound nor was inhibited by progesterone. However, isolated cell envelopes of N. gonorrhoeae and progesterone-insensitive bacteria all bound progesterone equally well. Cortisone and cholesterol, althouh structurally similar to progesterone, were not inhibitory to N. gonorrhoeae and did not bind to whole cells as well as progesterone. The major site of progesterone binding appeared to be the cytoplasmic membrane, which bound four times more progesterone than the outer membrane. In addition, isolated cytoplasmic membrane proteins bound more than three times more progesterone per milligram of protein than the intact membrane.
PMCID: PMC421497  PMID: 406199
18.  Gonorrhoea in inner London: results of a cross sectional study. 
BMJ : British Medical Journal  1997;314(7096):1719-1723.
OBJECTIVES: To estimate population based incidence rates of gonorrhoea in an inner London area and examine relations with age, ethnic group, and socioeconomic deprivation. DESIGN: Cross sectional study. SETTING: 11 departments of genitourinary medicine in south and central London. SUBJECTS: 1978 first episodes of gonorrhoea diagnosed in 1994 and 1995 in residents of 73 electoral wards in the boroughs of Lambeth, Southwark, and Lewisham who attended any of the departments of genitourinary medicine. MAIN OUTCOME MEASURES: Yearly age, sex, and ethnic group specific rates of gonorrhoea per 100,000 population aged 15-59 years; rate ratios for the effects of age and ethnic group on gonorrhoea rates in women and men before and after adjustment for confounding factors. RESULTS: Overall incidence rates of gonorrhoea in residents of Lambeth, Southwark, and Lewisham were 138.3 cases yearly per 100,000 women and 291.9 cases yearly per 100,000 men aged 15-59 years. At all ages gonorrhoea rates were higher in non-white minority ethnic groups. Rate ratios for the effect of age adjusted for ethnic group and underprivilege were 15.2 (95% confidence interval 11.6 to 19.7) for women and 2.0 (1.7 to 2.5) for men aged 15-19 years compared with those over 30. After deprivation score and age were taken into account, women from black minority groups were 10.5 (8.6 to 12.8) times as likely and men 11.0 (9.7 to 12.6) times as likely as white people to experience gonorrhoea. CONCLUSIONS: Gonorrhoea rates in Lambeth, Southwark, and Lewisham in 1994-5 were six to seven times higher than for England and Wales one year earlier. The presentation of national trends thus hides the disproportionate contribution of ongoing endemic transmission in the study area. Teenage women and young adult men, particularly those from black minority ethnic groups, are the most heavily affected, even when socioeconomic underprivilege is taken into account. There is urgent need for resources for culturally appropriate research and effective intervention to prevent gonococcal infections and their long term sequelae in this population.
PMCID: PMC2126883  PMID: 9185497
19.  Risk factors for gonorrhoea: case-control study. 
Genitourinary Medicine  1997;73(6):518-521.
OBJECTIVE: To define risk factors for gonococcal infection. METHODS: A case-control study comparing 200 gonorrhoea cases with 400 patients with non-gonococcal genitourinary infections and 400 patients with various skin diseases, all of them attending City Department for Skin and Venereal Diseases In Belgrade (Yugoslavia) from October 1993 to December 1994. RESULTS: According to multivariate logistic regression analysis the following factors were significantly related to gonorrhoea in men: education level, sexual contact same day as meeting, condom use, history of prior gonorrhoea, and casual and/or new sex partner in the past month. Age, sexual contact same day as meeting, number of partners in the past year, and frequency of sexual intercourse in the past month were independently, significantly related to gonorrhoea in women. Also, in females, gonorrhoea was significantly more frequent in industrial workers and supported people. CONCLUSION: Since sexual behaviour, low education level, younger ages, and low socioeconomic status were found to be related to gonococcal infection, health education at early age seems to be the most appropriate means of altering high risk behaviour.
PMCID: PMC1195937  PMID: 9582473
20.  Neisseria gonorrhoeae isolated at St. Mary's Hospital London, 1980-91. 
Genitourinary Medicine  1993;69(4):286-289.
OBJECTIVE--To describe and discuss the trends in the isolation of Neisseria gonorrhoeae from patients attending the Genitourinary Medicine Clinic at St. Mary's Hospital, Paddington, London between 1980 and 1991. DESIGN--A retrospective study of the total number of gonococci isolated over an eleven year period was performed. In addition, for the years 1988-1991 the number of isolates from homosexual men was analysed by age of the patient, site of infection and HIV antibody status of the patient. RESULTS--The total number of N. gonorrhoeae isolates identified declined markedly between 1980 and 1989 from 3670 to 750 isolates. Over the same time period the number of specimens screened for N. gonorrhoeae fell by 50%. In 1990 there was an increase in N. gonorrhoeae isolates but this was not maintained, and in 1991 the number of N. gonorrhoeae fell to its lowest level of 638 isolates. The decrease since 1980 occurred in both men and women although the number of rectal isolates from men showed a steeper decline reaching its lowest level of 24 isolates in 1988. The number of rectal isolates from homosexual men has since increased with a peak in 1990. Many of the infections among homosexual men occurred in older men and included insignificant number of patients who were HIV positive. CONCLUSION--Gonorrhoea among attenders at St. Mary's Hospital has declined dramatically since 1980 following trends reported from much of Europe. The increase in gonococcal isolates since 1989 and the peak in 1990 are unexplained but are coincident with a higher number of isolates from homosexual men.
PMCID: PMC1195089  PMID: 7721290
21.  A serovar analysis of heterosexual gonorrhoea in Edinburgh 1986-90. 
Genitourinary Medicine  1992;68(1):16-19.
OBJECTIVE--To analyse the frequency of different gonococcal serovars within Edinburgh, Scotland and to describe changes that occurred in the frequency of such serovars over time. METHODS--All heterosexual patients with a diagnosis of gonorrhoea confirmed on culture between January 1986 and December 1990 had their gonococcal strain serotyped. Temporal changes in the prevalence of gonorrhoea and the serovar of the isolates were analysed. RESULTS--Isolates of Neisseria gonorrhoeae from 1356 episodes of gonorrhoea were serotyped. Three serovars, Bajk (IB-3/IB-6), Bacejk (IB-1/IB-2) and Aedgkih (IA-1/IA-2), dominated, occurring in two-thirds of all infections. Over the study period Bajk (IB-3/IB-6) and Aedgkih (IA-1/IA-2) isolates declined in frequency in parallel with an overall fall in the prevalence of gonorrhoea but Bacejk (IB-1/IB-2) persisted at a lower but fairly constant level. Despite a fall in the number of gonococcal infections the variety of new serovars being isolated fluctuated. CONCLUSIONS--The ability of some serovars to persist while others decline in incidence may be partially related to antibiotic sensitivities but other factors such as an ability to evade the immune response and transfer of serovars from one population group to another may also be important.
PMCID: PMC1194791  PMID: 1548006
22.  Epidemiology of penicillin resistant Neisseria gonorrhoeae. 
Genitourinary Medicine  1991;67(4):307-311.
OBJECTIVE--To study the epidemiology of Neisseria gonorrhoeae that exhibit both chromosomal and plasmid-mediated resistance to penicillin. MATERIALS AND METHODS--A total of 1589 strains of N gonorrhoeae isolated from patients attending St Mary's Hospital, London were tested for both their susceptibility to penicillin and for their auxotype and serotype. RESULTS--Of the 940 non-penicillinase producing N gonorrhoeae, 840 were considered penicillin sensitive (MIC less than or equal to 0.5 mg/l) and 100 were chromosomally-mediated resistant N gonorrhoeae (CMRNG), (MIC greater than or equal to 1.0 mg/l). Of the 649 penicillinase producing N gonorrhoeae (PPNG), 429 carried the 4.4 megadalton (MDa) penicillinase encoding plasmid and 220 carried the 3.2 MDa plasmid. CMRNG were predominantly serogroup IB (90%). PPNG with 3.2 MDa plasmid were the only group more often serogroup IA (58%) than IB (42%). Serovar IA-1/2 and requirement for arginine, hypoxanthine and uracil (AHU) were associated with increased susceptibility to penicillin whereas serovar IB-5/7 was associated with decreased susceptibility in nonPPNG. There was a significant difference in the distribution of the IA and IB serovars between PPNG carrying either the 4.4 MDa or 3.2 MDa plasmid. AHU and PAOU requiring strains were not found among PPNG and were uncommon among CMRNG. CONCLUSION--Some clear associations have been found but the pattern among PPNG appears more complex and in most instances could be related to clusters of a single strain over a short time span.
PMCID: PMC1194706  PMID: 1916793
23.  Epidemiology and treatment of uncomplicated gonorrhoea caused by non-PPNG strains in Córdoba, Argentina: auxotypes, susceptibility profiles, and plasmid analyses of urethral isolates from men. 
Genitourinary Medicine  1987;63(4):246-249.
The official records of uncomplicated gonorrhoea for Córdoba state show that between 1975 and 1985, about one in 1000 sexually active people acquired gonorrhoea each year. A study was therefore undertaken to obtain information about treatment of uncomplicated gonorrhoea, as well as the nutritional requirements, plasmid analyses, and susceptibility profiles of gonococci in this geographical area. From August 1983 to April 1984, 219 men with uncomplicated gonorrhoea were treated with one of four antibiotic schedules, all of which were over 95% efficient. All 98 strains isolated and purified were non-penicillinase-producing Neisseria gonorrhoeae (non-PPNG). The minimum inhibitory concentrations (MICs) of benzylpenicillin, tetracycline, thiamphenicol, spectinomycin, kanamycin, and cefoxitin were assessed. The MIC of benzylpenicillin showed that 88% (86) of the strains were inhibited by 0.5 mg/l of the drug, and also showed a bimodal sensitivity pattern to that antibiotic. The nutritional requirements of the 62 strains tested showed that 53% (33) were of the non-requiring (wild type) auxotype, 42% (26) required proline (pro-) and 5% (3) required proline and arginine (pro- arg-). Resistance to antibiotics was more notable in the pro- than in the wild type strains.
PMCID: PMC1194077  PMID: 2958401
24.  Estimating the sexual mixing patterns in the general population from those in people acquiring gonorrhoea infection: theoretical foundation and empirical findings. 
STUDY OBJECTIVES--To describe mathematically the relationship between patterns of sexual mixing in the general population and those of people with gonorrhoea infection, and hence to estimate the sexual mixing matrix for the general population. DESIGN--Integration of data describing sexual behaviour in the general population, with data describing sexual behaviour and mixing among individuals infected with gonorrhoea. Use of these data in a simple mathematical model of the transmission dynamics of gonorrhoea infection. SETTING--The general population of London and a genitourinary medicine (GUM) clinic in west London. PARTICIPANT--These comprised 1520 men and women living in London who were randomly selected for the national survey of sexual attitudes and lifestyles and 2414 heterosexual men and women who presented to the GUM clinic with gonorrhoea. MAIN RESULTS--The relationship between sexual mixing among people with gonorrhoea and sexual mixing in the general population is derived mathematically. An empirical estimate of the sexual mixing matrix for the general population is presented. The results provide tentative evidence that individuals with high rates of acquisition of sexual partners preferentially select other individuals with high rates as partners (assortative mixing). CONCLUSIONS--Reliable estimates of sexual mixing have been shown to be important for understanding the evolution of the epidemics of HIV infection and other sexually transmitted diseases. The possibility of estimating patterns of sexual mixing in the general population from information routinely collected in gonorrhoea contact tracing programmes is demonstrated. Furthermore, the approach we describe could, in principle, be used to estimate the same patterns of mixing, using contact tracing data for other sexually transmitted diseases, thus providing a way of validating our results.
PMCID: PMC1060109  PMID: 7798052
25.  Interactions of Neisseria gonorrhoeae with Adherent Polymorphonuclear Leukocytes  
Infection and Immunity  2005;73(4):1971-1977.
Neisseria gonorrhoeae causes severe exudative urethritis. The exudates from infected individuals contain large numbers of polymorphonuclear leukocytes (PMN) with ingested gonococci. The fate of N. gonorrhoeae within PMN has been a topic of debate for years. In this study, we examined the interactions of N. gonorrhoeae with PMN adherent to surfaces as a system that better models events during clinical disease. Using chemiluminescence to measure reactive oxygen species (ROS), we found that N. gonorrhoeae stimulated PMN to produce a respiratory burst. Different kinetics were seen when PMN were stimulated with opsonized zymosan particles. In addition, ROS were produced predominantly inside the PMN in response to gonococci. Laser scanning confocal microscopy and transmission electron microscopy showed that N. gonorrhoeae rapidly associated with PMN under these experimental conditions and was internalized. Some gonococci were cleared in the first 30 to 60 min after phagocytosis, but a majority of the population persisted for 6 h after phagocytosis. Quantification of viable organisms showed that a significant portion of the population resisted killing. The viability of this subpopulation remained unchanged for 2 h after phagocytosis. A significant increase of viable gonococci from 1 to 6 h was also observed, suggesting intracellular replication. Four different N. gonorrhoeae strains demonstrated the same capacity to resist PMN-mediated killing, whereas Escherichia coli was rapidly killed by PMN under the same conditions. Taken together, these findings suggest that a subpopulation of N. gonorrhoeae resists killing and replicates within PMN phagosomes in spite of NADPH oxidase activation.
PMCID: PMC1087443  PMID: 15784537

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