Hepatitis G virus (HGV) is an RNA virus. It is mainly transmitted through exposure to contaminated blood although other routes may also exist. Patients with chronic renal failure (CRF) are at high risk of acquiring HGV because they require frequent blood transfusions. Ongoing HGV infection can be only diagnosed by demonstrating viremia in patient sample by reverse transcriptase (RT) PCR. Antibodies to the envelop protein E2 (anti E2) of HGV is an indicator of virus clearance and testify past HGV contact. This cross sectional study was done to assess the frequency of HGV exposure (ongoing and past infection) in Egyptian children with CRF and to study the possible risk factors of infection.
This study included 100 children with CRF [34 on regular haemodialysis (HD) and 66 before the start of dialysis (predialysis)]. All patients sera were tested for HGV RNA by RT-PCR, anti E2, hepatitis C virus (HCV) antibody, hepatitis B surface antigen (HBsAg), and hepatitis B core antibody (HBcAB). Twenty five healthy children of matched age & sex were used as controls.
HGV RNA was positive in 9 (26.5%) of HD and 9 (13.6%) of predialysis children. Anti E2 was positive in 14 (41.2%) of HD and 19 (28.8%) of predialysis children.
In comparison to controls; CRF (n = 100); HD and predialysis children had significantly higher prevalence of anti E2 [4% VS 33% for all CRF cases; (p = 0.002)& 41.2% (p = 0.002) and 28.8% (p = 0.01); for HD and predialysis groups; respectively]. HGV RNA was significantly more prevalent only in HD children in comparison to controls (p = 0.03). HD and predialysis children did not have significant difference in the prevalence of HGV RNA (p = 0.16) or anti E2 (p = 0.26).
HGV exposure was not correlated with positivity of anti HCV (p = 0.32), HCV RNA (0.09), HBsAg/HBcAB (p = 1), age (p = 0.06), or gender (p = 0.83). It was significantly correlated with duration of the disease (p < 0.001). Ongoing HGV infection was significantly more prevalent with frequent blood transfusion (p < 0.001). There were no significant differences in serum levels of ALT (p = 0.09), total bilirubin (p = 0.1) and albumin (p = 0.06) in children with ongoing infection in comparison to healthy controls.
The frequency of HGV exposure in Egyptian children with CRF appears to be high and is mainly related to frequent blood transfusions and longer disease duration. HGV infection in these children is not associated with significant changes in hepatic biochemical parameters.
In the last few years, several outbreaks of nosocomial infections caused by multidrug-resistant pathogenic agents have been observed, and various biocides products were developed in order to control this phenomenon. We investigated the efficacy of two natural biodetergents composed of plants and kelps extracts, BATT1 and BATT2, against multidrug-resistant strains.
In-vitro antibacterial efficacy of BATT1 and BATT2 against nosocomial multidrug-resistant isolates was assessed using a suspension-inhibition test, with and without bovine serum albumin (BSA). The test was also carried out on glass surfaces with and without BSA.
In vitro tests with both biocidal disinfectants at 25% concentration demonstrated an overall drop in bacterial, mould and yeast counts after 10 min of contact with or without organic substances. For Pseudomonas aeruginosa, it was necessary to use undiluted disinfectants with and without an organic substance. The same results were obtained in tests carried out on glass surfaces for all strains.
The natural products BATT1 and BATT2 behave like good biocides even in presence of organic substances. The use of both disinfectants may be beneficial for reducing hospital-acquired pathogens that are not susceptible to disinfectants.
However, it has to be stressed that all these experiments were carried out in vitro and they still require validation from use in clinical practice.
The aim of our study was to compare the presence of the intI1 gene and its associations with the antibiotic resistance of commensal Escherichia coli strains in children with/without previous antibiotic treatments and elderly hospitalized/healthy individuals.
One-hundred-and-fifteen intestinal E. coli strains were analyzed: 30 strains from 10 antibiotic-naive infants; 27 from 9 antibiotic-treated outpatient infants; 30 from 9 healthy elderly volunteers; and 28 from 9 hospitalized elderly patients. The MIC values of ampicillin, cefuroxime, cefotaxime, gentamicin, ciprofloxacin, and sulfamethoxazole were measured by E-test and IntI1 was detected by PCR.
Out of the 115 strains, 56 (49%) carried class 1 integron genes. Comparing persons without medical interventions, we found in antibiotic-naive children a significantly higher frequency of integron-bearing strains and MIC values than in healthy elderly persons (53% versus 17%; p < 0.01). Evaluating medical interventions, we found a higher resistance and frequency of integrons in strains from hospitalized elderly persons compared with non-hospitalized ones. Children treated with antibiotics had strains with higher MIC values (when compared with antibiotic-naive ones), but the integron-bearing in strains was similar. In most cases, the differences in resistance between the groups (integron-positive and negative strains separately) were higher than the differences between integron-positive and negative strains within the groups.
The prevalence of integrons in commensal E. coli strains in persons without previous medical intervention depended on age. The resistance of integron-carrying and non-carrying strains is more dependent on influencing factors (hospitalization and antibiotic administration) in particular groups than merely the presence or absence of integrons.
Group A beta hemolytic streptococcus (GABHS) pharyngitis is a common childhood illness. Penicillin remains the gold standard therapy, but macrolides are indicated for the penicillin allergic patient, and are often used for convenience.
We conducted a surveillance study of children with pharyngitis and positive streptococcal rapid antigen testing from 10/05 to 10/06 at 2 sites (A & B). Demographics, treatment, and resistance data was collected and compared to previous data from 2002. Erythromycin (EM) resistance was determined by disk diffusion and E-test on 500 isolates. Pulse field gel electrophoresis (PFGE) was performed to measure genetic relatedness of isolates. StatXact version 8 software (Cytel Inc., Cambridge, MA) was utilized to perform Fisher's exact test and exact confidence interval (CI) analysis.
There were no differences in resistance rates or demographic features, with the exception of race, between sites A & B. EM resistance was 0 in 2002, 3.5% in 2005-06 at site A, and 4.5% in 2005-06 at site B. 3/7 and 3/9 had inducible resistance at A and B respectively. 8 isolates had relatedness ≥80%, 5 of which were 88% homologous on PFGE.
Community macrolide resistance has increased following increased macrolide use. These results may have treatment implications if use continues to be high.
Tuberculous spondylitis (Pott's disease) is an ancient human disease. Because it is rare in high-income, tuberculosis (TB) low incidence countries, misdiagnoses occur as sufficient clinical experience is lacking.
We describe a fatal case of a patient with spinal TB, who was mistakenly irradiated for suspected metastatic lung cancer of the spine in the presence of a solitary pulmonary nodule of the left upper lobe. Subsequently, the patient progressed to central nervous system TB, and finally, disseminated TB before the accurate diagnosis was established. Isolation and antimycobacterial chemotherapy were initiated after an in-hospital course of approximately three months including numerous health care related contacts and procedures.
The rapid diagnosis of spinal TB demands a high index of suspicion and expertise regarding the appropriate diagnostic procedures. Due to the devastating consequences of a missed diagnosis, Mycobacterium tuberculosis should be considered early in every case of spondylitis, intraspinal or paravertebral abscess. The presence of certain alarm signals like a prolonged history of progressive back pain, constitutional symptoms or pulmonary nodules on a chest radiograph, particularly in the upper lobes, may guide the clinical suspicion.
Lung transplant recipients have an increased risk for actinomycetales infection secondary to immunosuppressive regimen.
A case of pulmonary infection with bacteremia due to Tsukamurella tyrosinosolvens in a 54-year old man who underwent a double lung transplantation four years previously is presented.
The identification by conventional biochemical assays was unsuccessful and hsp gene sequencing was used to identify Tsukamurella tyrosinosolvens.
Stryphnodendron adstringens (Mart.) Coville, Leguminosae, also known in Brazil as barbatimão, is rich in tannins and many flavan-3-ols and proanthocyanidins such as prodelphinidins and prorobinetinidins. Previous studies have demonstrated several pharmacological properties of tannins from barbatimão, including anti-candidal activity.
The antifungal activity of proanthocyanidin polymeric tannins from Stryphnodendron adstringens (subfraction F2.4) was evaluated against three strains of Cryptococcus neoformans with different capsule expressions, using the broth microdilution technique, light microscopy and transmission electron microscopy. The effect of subfraction F2.4 on C. neoformans and melanoma mammalian cells pigmentation was also evaluated.
Although susceptibility assays revealed MIC values quite similar (between 2.5 and 5.0 μg/ml), analyses of MFC values revealing that the acapsular mutant Cap 67 was more susceptible to be killed by the subfraction F2.4 (MFC = 20 μg/ml) than the two tested capsular strains (T1-444 and ATCC 28957) (MFC > 160 μg/ml). Optical and electron microscopy experiments revealed relevant alterations in cell shape and size in all strains treated with 1 and 2.5 μg/ml of subfraction F2.4. Capsule size of the capsular strains decreased drastically after subfraction F2.4 treatment. In addition, ultrastructural alterations such as cell wall disruption, cytoplasm extraction, mitochondria swelling, increase in the number of cytoplasmic vacuoles and formation of membranous structures in the cytoplasm were also observed in treated yeasts. Incubation with subfraction F2.4 also decreased C. neoformans pigmentation, however, did not interfere in melanization of B16F10 mammalian cells.
Our data indicate that tannins extracted from S. adstringens interfered with growth, capsule size and pigmentation, all important virulence factors of C. neoformans, and may be considered as a putative candidate for the development of new antifungal agents.
Staphylococcus aureus and S. epidermidis biofilms differ in structure, growth and regulation, and thus the high-throughput method of evaluating biofilm susceptibility that has been published for S. epidermidis cannot be applied to S. aureus without first evaluating the assay's reproducibility and reliability with S. aureus biofilms.
Staphylococcus aureus biofilms were treated with eleven approved antibiotics, lysostaphin, or Conflikt®, exposed to the oxidation reduction indicator Alamar blue, and reduction relative to untreated controls was determined visually and spectrophotometrically. The minimum biofilm inhibitory concentration (MBIC) was defined as ≤ 50% Alamar blue reduction and a purple/blue well 60 min after the addition of Alamar blue. Because all of the approved antibiotics had MBICs >128 μg/ml (most >2048 μg/ml), lysostaphin and Conflikt®, with relatively low MBICs, were used to correlate Alamar blue reduction with 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction and viable counts (CFU/ml) for S. aureus ATCC 29213 and three clinical isolates. Alamar blue's stability and lack of toxicity allowed CFU/ml to be determined from the same wells as Alamar blue absorbances.
Overall, Alamar blue reduction had excellent correlation with XTT reduction and with CFU/ml. For ATCC 29213 and two clinical isolates treated with lysostaphin or Conflikt®, Alamar blue reduction had excellent correlation with XTT reduction (r = 0.93-0.99) and with CFU/ml (r = 0.92-0.98). For one of the clinical isolates, the results were moderately correlated for Conflikt® (r = 0.76, Alamar blue vs. XTT; r = 0.81, Alamar blue vs. CFU/ml) and had excellent correlation for lysostaphin (r = 0.95, Alamar blue vs. XTT; r = 0.97, Alamar blue vs. CFU/ml).
A reliable, reproducible method for evaluating biofilm susceptibility was successfully applied to S. aureus biofilms. The described method provides researchers with a simple, nontoxic, relatively inexpensive, high throughput measure of viability after drug treatment. A standardized biofilm Alamar blue assay should greatly increase the rate of discovery of S. aureus biofilm specific agents.
The aims of this study were to determine the antimicrobial susceptibility patterns of urinary isolates from community acquired acute uncomplicated urinary tract infections (uUTI) and to evaluate which antibiotics were empirically prescribed in the outpatient management of uUTI.
Among the patients which were admitted to outpatient clinics of Ankara University Medical Faculty, Ibni-Sina Hospital during 2005-2006, a total of 429 women between the age of 18 and 65 years old who were clinically diagnosed with uUTI and to whom prescribed empirical antibiotics were enrolled in this prospective observational study. Patients' demographical data, urine culture results, resistance rates to antimicrobial agents and prescribed empiric antimicrobial therapy were analyzed.
Totally 390 (90.9%) patients among all study population were requested for urine culture by their physicians. 150 (38.5%) of these urine cultures were positive. The most common isolated uropathogen was Escherichia coli (E. coli) (71.3%). The variations of uropathogens according to age and menopause status were not significantly different.
The resistance rates of E. coli isolates for ampicillin, ampicillin-sulbactam, amoxicillin-clavulonate, cefuroxime, ceftriaxone, fluoroquinolones (FQ), co-trimoxazole (TMP-SMX) and gentamicin were 55.1%, 32.7%, 32.7%, 23.4%, 15.9%, 25.2%, 41.1%, 6.1% respectively. FQ were the most common prescribed antibiotics (77.9%) (P < 0.001), followed by TMP-SMX (10.7%), fosfomycin (9.2%), nitrofurantoin (2.1%). Treatment durations were statistically longer than the recommended 3-day course (P < 0.001).
Empirical use of FQ in uUTI should be discouraged because of increased antimicrobial resistance rates.
Infectious diseases are the leading cause of morbidity and mortality in the developing world. In Egypt bacterial diseases constitute a great burden, with several particular bacteria sustaining the leading role of multiple serious infections. This article addresses profound bacterial agents causing a wide array of infections including but not limited to pneumonia and meningitis. The epidemiology of such infectious diseases and the prevalence of Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae are reviewed in the context of bacterial meningitis. We address prevalent serotypes in Egypt, antimicrobial resistance patterns and efficacy of vaccines to emphasize the importance of periodic surveillance for appropriate preventive and treatment strategies.
Chromobacterium violaceum is a Gram negative facultative anaerobic bacillus, found in soil and stagnant water, that usually has a violet pigmented appearance on agar culture. It is rarely described as a human pathogen, mostly from tropical and subtropical areas.
A 53 year-old farmer died with Chromobacterium violaceum septicemia in Laos. A modified oxidase method was used to demonstrate that this violacious organism was oxidase positive. Forensic analysis of the glucose-6-phosphate dehydrogenase genotypes of his family suggest that the deceased patient did not have this possible predisposing condition.
C. violaceum infection should be included in the differential diagnosis in patients presenting with community-acquired septicaemia in tropical and subtropical areas. The apparently neglected but simple modified oxidase test may be useful in the oxidase assessment of other violet-pigmented organisms or of those growing on violet coloured agar.
Invasive fungal infections are a major cause of mortality among patients at risk. Treatment guidelines vary on optimal treatment strategies. We aimed to determine the effects of different antifungal therapies on global response rates, mortality and safety.
We searched independently and in duplicate 10 electronic databases from inception to May 2009. We selected any randomized trial assessing established antifungal therapies for confirmed cases of invasive candidiasis among predominantly adult populations. We performed a meta-analysis and then conducted a Bayesian mixed treatment comparison to differentiate treatment effectiveness. Sensitivity analyses included dosage forms of amphotericin B and fluconazole compared to other azoles.
Our analysis included 11 studies enrolling a total of 965 patients. For our primary analysis of global response rates, we pooled 7 trials comparing azoles to amphotericin B, Relative Risk [RR] 0.87 (95% Confidence Interval [CI], 0.78–0.96, P = 0.007, I2 = 43%, P = 0.09. We also pooled 2 trials of echinocandins versus amphotericin B and found a pooled RR of 1.10 (95% CI, 0.99–1.23, P = 0.08). One study compared anidulafungin to fluconazole and yielded a RR of 1.26 (95% CI, 1.06–1.51) in favor of anidulafungin. We pooled 7 trials assessing azoles versus amphotericin B for all-cause mortality, resulting in a pooled RR of 0.88 (95% CI, 0.74–1.05, P = 0.17, I2 = 0%, P = 0.96). Echinocandins versus amphotericin B (2 trials) for all-cause mortality resulted in a pooled RR of 1.01 (95% CI, 0.84–1.20, P = 0.93). Anidulafungin versus fluconazole resulted in a RR of 0.73 (95% CI, 0.48–1.10, P = 0.34). Our mixed treatment comparison analysis found similar within-class effects across all interventions. Adverse event profiles differed, with amphotericin B exhibiting larger adverse event effects.
Treatment options appear to offer preferential effects on response rates and mortality. When mycologic data are available, therapy should be tailored.
The aim of our study was to trace the dynamic changes of hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) lineages in Italy, comparing the genotypic backgrounds of contemporary isolates over a period of 17 years, with those of a sample of early MRSA strains from 1980.
In total, 301 non-repetitive MRSA clinical isolates, recovered from 19 Italian hospitals between 1990 and 2007 were selected and analyzed for their antibiotic resistance, typed by PFGE and SCCmec, grouped into clonal-types and further characterized using Multi Locus Sequence Typing (MLST). A sample of fifteen early MRSA strains from 1980 was also used for comparison.
The most interesting feature was the recent increase of ST228-MRSA-I (formerly the Italian clone; PFGE E) over the period 2000–2007 (57%), when compared to the period 1990–1999 (29%), and its stability to date, associated with a decrease of the highly epidemic ST247-MRSA-IA (formerly the Iberian clone; PFGE A), (23% from 1990 to 1999, 6% from 2000 to 2007). ST1-MRSA-I (1 out of 2 strains carrying ccrA2B2), ST8-MRSA-I (4 strains), ST15-MRSA-I (1 out of 4 carrying ccrA2B2) and ST30-MRSA-I (2 out of 5 carrying no ccrAB-types and ccrC) were the predominant earliest STs among the MRSA strains in 1980.
A temporal shift in the susceptibility levels to glycopeptides was observed: strains with vancomycin MIC of ≥ 2 mg/L increased from 19.4% to 35.5%.
In conclusion, we describe the alternation of MRSA clones that occurred in hospitals from 1990 to 2007 and the increase of the glycopeptide MIC levels, reflecting a worldwide trend. We document the detection of ST1, ST8, ST15 and ST30 in the 1980 isolates; we hypothesize their possible latency and their appearance as the current CA-MRSA clones.
Over the last decade, nosocomial infections due to Acinetobacter baumannii have been described with an increasing trend towards multidrug resistance, mostly in intensive care units. The aim of the present study was to determine the clonal relatedness of clinical isolates and to elucidate the genetic basis of imipenem resistance.
A. baumannii isolates (n = 83) originated from two hospital settings in central Ohio were used in this study. Pulsed-field gel electrophoresis genotyping and antimicrobial susceptibility testing for clinically relevant antimicrobials were performed. Resistance determinants were characterized by using different phenotypic (accumulation assay for efflux) and genotypic (PCR, DNA sequencing, plasmid analysis and electroporation) approaches.
The isolates were predominantly multidrug resistant (>79.5%) and comprised of thirteen unique pulsotypes, with genotype VII circulating in both hospitals. The presence of blaOXA-23 in 13% (11/83) and ISAba1 linked blaOXA-66 in 79.5% (66/83) of clinical isolates was associated with high level imipenem resistance. In this set of OXA producing isolates, multidrug resistance was bestowed by blaADC-25, class 1 integron-borne aminoglycoside modifying enzymes, presence of sense mutations in gyrA/parC and involvement of active efflux (with evidence for the presence of adeB efflux gene).
This study underscores the major role of carbapenem-hydrolyzing class D β-lactamases, and in particular the acquired OXA-23, in the dissemination of imipenem-resistant A. baumannii. The co-occurrence of additional resistance determinant could also be a significant threat.
Mentha longifolia L. (Lamiaceae) leaves have been traditionally implemented in the treatment of minor sore throat and minor mouth or throat irritation by the indigenous people of Iraq, although the compounds responsible for the medicinal properties have not been identified. In the present study, an antimicrobial compound was isolated and characterized, and its biological activity was assessed.
The compound was isolated and characterized from the extracted essential oil using different spectral techniques: TLC, FTIR spectra and HPLC. Antimicrobial activity of the compound was assessed using both disc diffusion and microdilution method in 96 multi-well microtiter plates.
A known compound was isolated from the essential oil of the plant and was identified as (-) menthol. The isolated compound was investigated for its antimicrobial activity against seven selected pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa and the yeast Candida albicans. Menthol at different concentrations (1:1, 1:5, 1:10, 1:20) was active against all tested bacteria except for P. aeruginosa, and the highest inhibitory effect was observed against S. mutans (zone of inhibition: 25.3 mm) using the disc diffusion method. Minimal inhibitory concentration MIC values ranged from 15.6–125.0 μg/ml, and the most promising results were observed against S. aureus and S. mutans (MIC 15.6 μg/ml) while, S. faecalis, S. pyogenis and L. acidophilus ranked next (MIC 31.2 μg/ml). Furthermore, menthol achieved considerable antifungal activity against the yeast C. albicans (zone of inhibition range: 7.1–18.5 mm; MIC: 125.0).
The isolation of an antimicrobial compound from M. longifolia leaves validates the use of this plant in the treatment of minor sore throat and minor mouth or throat irritation.
Malaria remains one of the most important tropical diseases of human with 1–2 million deaths annually especially caused by P. falciparum. During malarial life cycle, they exposed to many environmentally stresses including wide temperature fluctuation and pharmacological active molecules. These trigger malarial evolutionarily adaptive responses. The effect of febrile temperature on malarial growth, development and drug susceptibility by mimicking patient in treatment failure before and after drug uptake was examined.
Sensitivities of P. falciparum to antimalarial drug (chloroquine, mefloquine, quinine and artesunate) were investigated based on the incorporation of [3H] hypoxanthine into parasite nucleic acids or radioisotopic technique. The number of parasites was examined under microscope following Giemsa staining and the parasite development at the end of each phase was counted and comparison of parasite number was made. The proteome was separated, blotted and hybridized with anti-Hsp70s primary antibody. The hybridized proteins were separately digested with trypsin and identified by MALDI-TOF peptide mass fingerprint.
The results show that febrile temperature is capable of markedly inhibiting the growth of field isolate P. falciparum but not to K1 and 3D7 standard strains. K1 and 3D7 grown under heat shock developed greater and the reinfection rate was increased up to 2-folds when compared to that of non-heat shock group. The IC50 value of K1 toward chloroquine, mefloquine and quinine under heat shock was higher than that of K1 under non-heat shock which is opposite to that of 3D7. Heat shock caused death in field isolated parasite. It was also found that the febrile temperature coped with chloroquine uptake had no effect to the development, drug sensitivity and the parasite number of K1 strain. In the opposite way, heat shock and chloroquine shows extremely effect toward 3D7 and field isolate PF91 as shown by higher number of dead parasites compared to that of control group. After culture under high temperature with artesunate, the total parasite number of all strains including K1, 3D7 and PF91 was extremely decreased and the parasite was not found at the end. Additionally, the expression of pfHsp70s was found in all strains and conditions as shown in 120 kDa hybridized band. However, the proteome extracted from K1 grown under heat shock with chloroquine, anti-pfHsp70 interacted with additional three bands identified by MALDI-TOF as elongation factor-1α (83 kDa), pfHsp86 (60 kDa) and phosphoethanolamine N-methyltransferase (43 kDa).
In conclusion, febrile temperature was capable of markedly inhibiting the growth of field isolate P. falciparum while the development, reinfection rate and drug (chloroquine, mefloquine and quinine) resistant level of standard strain K1 was enhanced. However, the febrile temperature coped with chloroquine had no effect to the development, drug sensitivity and the parasite number of K1 strain. In the opposite way, heat shock and chloroquine showed extremely effect toward 3D7 and field isolate PF91 as shown by some died parasites. Heat shock protein 70 (pfHSP70) of strain K1 under heat shock with chloroquine might involved in many pathways in order to sustain the parasite.
Infections sustained by multidrug-resistant (MDR) and pan-resistant Acinetobacter baumannii have become a challenging problem in Intensive Care Units. Tigecycline provided new hope for the treatment of MDR A. baumannii infections, but isolates showing reduced susceptibility have emerged in many countries, further limiting the therapeutic options. Empirical combination therapy has become a common practice to treat patients infected with MDR A. baumannii, in spite of the limited microbiological and clinical evidence supporting its efficacy. Here, the in vitro interaction of tigecycline with seven commonly used anti-Acinetobacter drugs has been assessed.
Twenty-two MDR A. baumannii isolates from Intensive Care Unit (ICU) patients and two reference strains for the European clonal lineages I and II (including 3, 15 and 6 isolates that were resistant, intermediate and susceptible to tigecycline, respectively) were tested. Antimicrobial agents were: tigecycline, levofloxacin, piperacillin-tazobactam, amikacin, imipenem, rifampicin, ampicillin-sulbactam, and colistin. MICs were determined by the broth microdilution method. Antibiotic interactions were determined by chequerboard and time-kill assays. Only antibiotic combinations showing synergism or antagonism in both chequerboard and time-kill assays were accepted as authentic synergistic or antagonistic interactions, respectively.
Considering all antimicrobials in combination with tigecycline, chequerboard analysis showed 5.9% synergy, 85.7% indifference, and 8.3% antagonism. Tigecycline showed synergism with levofloxacin (4 strains; 16.6%), amikacin (2 strains; 8.3%), imipenem (2 strains; 8.3%) and colistin (2 strains; 8.3%). Antagonism was observed for the tigecycline/piperacillin-tazobactam combination (8 strains; 33.3%). Synergism was detected only among tigecycline non-susceptible strains. Time-kill assays confirmed the synergistic interaction between tigecycline and levofloxacin, amikacin, imipenem and colistin for 5 of 7 selected isolates. No antagonism was confirmed by time-kill assays.
This study demonstrates the in vitro synergistic activity of tigecycline in combination with colistin, levofloxacin, amikacin and imipenem against five tigecycline non-susceptible A. baumannii strains, opening the way to a more rationale clinical assessment of novel combination therapies to combat infections caused by MDR and pan-resistant A. baumannii.
Vibrio spp. is a pathogen rarely isolated in cancer patients, and in most cases it is associated with haematological diseases. Cutaneous manifestations of this organism are even rarer. We report a case of Non-O1 Vibrio cholerae inguinal skin and soft tissue infection presenting bullous skin lesions in a young type II diabetic patient with a penis squamous cell carcinoma having a seawater exposure history.
Non-typhoidal Salmonella (NTS) is increasingly recognized as an important pathogen associated with bacteraemia especially in immunosuppressed patients. However, there is limited data specifically describing the clinical characteristics and outcome amongst the immunosuppressed patients.
A total of 56,707 blood culture samples and 5,450 stool samples were received by the microbiology laboratory at a tertiary referral hospital in Malaysia, during a 4-year study period. Out of these samples, 55 non-duplicate NTS isolates were identified from blood and 121 from stool. A retrospective analysis of the 55 patients with NTS bacteraemia was then conducted to determine the predominant NTS serovars causing bacteraemia and its' blood invasive potential, epidemiological data, clinical characteristics and antimicrobial susceptibility. Patients were then grouped as immunosuppressed and non-immunosuppressed to determine the association of severe immunosuppression on clinical features. Data was analyzed using the Statistical Package for Social Sciences (SPSS version 15.0) using the non-parametric Mann-Whitney test, Fisher's exact test or Chi-squared test. The odds ratio (OR) and its 95% confidence intervals (CI) were calculated. The P-value < 0.05 (two-tailed) was taken as the level of significance.
Out of 55 NTS bacteraemia cases identified, 81.8% (45/55) were community-acquired. Salmonella enterica serovar Enteritidis had the highest blood invasiveness. An extra-intestinal focus of infection was noted in 30.9% (17/55) of the patients, most commonly involving the lungs and soft tissue. 90.9% (50/55) of the patients had an underlying disease and 65.5% (36/55) of the patients had severe clinical immunosuppressive condition with malignancy and HIV being the most common. Immunosuppressed patients had higher mortality (P = 0.04), presented more commonly with primary bacteraemia (P = 0.023), leukopenia (P = 0.001) and opportunistic infections (P = 0.01). In contrast, atherosclerotic conditions (P = 0.015), mycotic aneurysms (0.037) and gastroenteritis (P = 0.03), were significantly more common in the non-immunosuppressed patients. The non-immunosuppressed group also had a higher proportion of older patients (>50 years) with a significantly higher median age (64 versus 36.5 years; p = 0.005).
Patients with severe clinical immunosuppression had higher mortality, presented more commonly with primary bacteraemia, leukopenia and opportunistic infections and absence of gastroenteritis. Early identification and prompt medical treatment can be life saving because of the high mortality and morbidity associated with this disease especially in the immunosuppressed patients.
Due to the indiscriminate use of antimicrobial drugs, the emergence of human pathogenic microorganisms resistant to major classes of antibiotics has been increased and has caused many clinical problems in the treatment of infectious diseases. Thus, the aim of this study was to evaluate for the first time the in vitro antimicrobial activity and brine shrimp lethality of extracts and isolated compounds from Zeyheria tuberculosa (Vell.) Bur., a species used in Brazilian folk medicine for treatment of cancer and skin diseases.
Using the disc diffusion method, bioautography assay and brine shrimp toxicity test (Artemia salina Leach), we studied the antimicrobial activity and lethality of extracts and isolated compounds against three microorganisms strains, including Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria and yeasts (Candida albicans).
In this study, the extracts inhibited S. aureus (8.0 ± 0.0 to 14.0 ± 0.0 mm) and C. albicans (15.3 ± 0.68 to 25.6 ± 0.4 mm) growth. In the brine shrimp test, only two of them showed toxic effects (LC50 29.55 to 398.05 μg/mL) and some extracts were non-toxic or showed weak lethality (LC50 705.02 to > 1000 μg/mL). From these extracts, four flavones [5,6,7,8-tetramethoxyflavone (1), 5,6,7-trimethoxyflavone (2), 4'-hydroxy-5,6,7,8-tetramethoxyflavone (3), and 4'-hydroxy-5,6,7-trimethoxyflavone (4)] were isolated through bioassay-guided fractionation and identified based on the 1D and 2D NMR spectral data. By bioautography assays, compounds 1 [S. aureus (16.0 ± 0.0 mm) and C. albicans (20.0 ± 0.0 mm)] and 3 [S. aureus (10.3 ± 0.6 mm) and C. albicans (19.7 ± 0.6 mm)] inhibited both microorganisms while 2 inhibited only S. aureus (11.7 ± 0.6 mm). Compound 4 did not restrain the growth of any tested microorganism.
Our results showed that extracts and isolated flavones from Z. tuberculosa may be particularly useful against two pathogenic microorganisms, S. aureus and C. albicans. These results may justify the popular use this species since some fractions tested had antimicrobial activity and others showed significant toxic effects on brine shrimps. However, in order to evaluate possible clinical application in therapy of infectious diseases, further studies about the safety and toxicity of isolated compounds are needed.
Helicobacter pylori has been strongly associated with chronic gastritis, peptic and duodenal ulcers, and it is a risk factor for gastric cancer. Three major virulence factors of H. pylori have been described: the vacuolating toxin (VacA), the cytotoxin-associated gene product (CagA) and the adhesion protein BabA2. Since considerable geographic diversity in the prevalence of H. pylori virulence factors has been reported, the aim of this work was to establish the H. pylori and vacA, cagA and babA2 gene status in 238 adult patients, from a marginal urban area of Mexico, with chronic gastritis.
H. pylori was identified in cultures of gastric biopsies by nested PCR. vacA and cagA genes were detected by multiplex PCR, whereas babA2 gene was identified by conventional PCR.
H. pylori-positive biopsies were 143 (60.1%). All H. pylori strains were vacA+; 39.2% were cagA+; 13.3% were cagA+ babA2+ and 8.4% were babA2+. Mexican strains examined possessed the vacA s1, m1 (43.4%), s1, m2 (24.5%), s2, m1 (20.3%) and s2, m2 (11.9%) genotypes.
These results show that the Mexican patients suffering chronic gastritis we have studied had a high incidence of infection by H. pylori. Forty four percent (63/143) of the H. pylori strains analyzed in this work may be considered as highly virulent since they possessed two or three of the virulence markers analyzed: vacA s1 cagA babA2 (9.8%, 14/143), vacA s1 babA2 (4.9%, 7/143), and vacA s1 cagA (29.4%, 42/143). However, a statistically significant correlation was not observed between vacAs1, cagA and babA2 virulence markers (χ2 test; P > 0.05).
Farnesol is a sesquiterpene alcohol produced by many organisms, and also found in several essential oils. Its role as a quorum sensing molecule and as a virulence factor of Candida albicans has been well described. Studies revealed that farnesol affect the growth of a number of bacteria and fungi, pointing to a potential role as an antimicrobial agent.
Growth assays of Paracoccidioides brasiliensis cells incubated in the presence of different concentrations of farnesol were performed by measuring the optical density of the cultures. The viability of fungal cells was determined by MTT assay and by counting the colony forming units, after each farnesol treatment. The effects of farnesol on P. brasiliensis dimorphism were also evaluated by optical microscopy. The ultrastructural morphology of farnesol-treated P. brasiliensis yeast cells was evaluated by transmission and scanning electron microscopy.
In this study, the effects of farnesol on Paracoccidioides brasiliensis growth and dimorphism were described. Concentrations of this isoprenoid ranging from 25 to 300 μM strongly inhibited P. brasiliensis growth. We have estimated that the MIC of farnesol for P. brasiliensis is 25 μM, while the MLC is around 30 μM. When employing levels which don't compromise cell viability (5 to 15 μM), it was shown that farnesol also affected the morphogenesis of this fungus. We observed about 60% of inhibition in hyphal development following P. brasiliensis yeast cells treatment with 15 μM of farnesol for 48 h. At these farnesol concentrations we also observed a significant hyphal shortening. Electron microscopy experiments showed that, despite of a remaining intact cell wall, P. brasiliensis cells treated with farnesol concentrations above 25 μM exhibited a fully cytoplasmic degeneration.
Our data indicate that farnesol acts as a potent antimicrobial agent against P. brasiliensis. The fungicide activity of farnesol against this pathogen is probably associated to cytoplasmic degeneration. In concentrations that do not affect fungal viability, farnesol retards the germ-tube formation of P. brasiliensis, suggesting that the morphogenesis of this fungal is controlled by environmental conditions.
Intravesical administration of Bacillus Calmette-Guérin is used as a treatment method in superficial bladder cancer. While it is generally well tolerated, serious side effects may develop. Granulomatous hepatitis cases have been previously reported; however, only one case with tuberculous peritonitis exists in the current literature. We hereby present two cases, one of which is the second tubercular peritonitis case following Bacillus Calmette-Guérin treatment to be reported, and the other a case with granulomatous hepatitis. Complete cure was achieved in both cases with specific therapy. In the patient who developed peritonitis, intravesical Bacillus Calmette-Guérin therapy was recommenced after antituberculosis treatment, and completed without further complications.