Since publication of our article (Ahmed and Sechi: Ann Clin Microbiol Antimicrob 2005, 4:1), we have noticed several errors.
The aim of this study was to investigate the efficacy and safety of colistin therapy in pediatric patients with severe nosocomial infections in pediatric intensive care unit.
The medical records of patients treated with colistin at a 200-bed university children hospital were reviewed.
Thirty-one patients (male/female = 22/9; median age, 3 years; range, 3 months-17 years) received forty-one courses of colistin. The average dose of colistin was 4.9 ± 0.5 mg/kg/day and average treatment duration was 19.8 ± 10.3 days. Three patients who received concomitant nephrotoxic agent with colistin developed nephrotoxicity. Colistin treatment was well tolerated in other patients, and neurotoxicity was not seen in any patient. Favourable outcome was achieved in 28 (68.3%) episodes. Twelve patients died during the colistin therapy. Six of these patients died because of primary underlying disease. The infection-related mortality rate was found 14.6% in this study.
In our study, colistin therapy was found to be acceptable treatment option for the severe pediatric nosocomial infections caused by multi-drug resistant bacteria. However, the use of concomitant nephrotoxic drugs with colistin must be avoided and renal function test should be closely monitored.
Colistin; Child; Multi-drug resistant bacteria; Nosocomial infection; Nephrotoxicity
The latest threat of multidrug-resistant Gram-negative bacteria corresponds to the emergence of carbapenemase New Delhi metallo-β-lactamase (NDM) and Klebsiella pneumoniae carbapenemase (KPC) producers. Rapid molecular detection is essential to limit their spread. In this study, a duplex real-time polymerase chain reaction (PCR) that was specific for the detection of blaNDM and blaKPC with the same limit of detection of ten plasmid copies was developed. The assay was linear over eight log dilutions for blaNDM (R2 = 0.971; slope, -3.273) and blaKPC (R2 = 0.992; slope, -2.997) with efficiencies of 102% and 115%, respectively. The assay was validated with 157 clinical isolates and showed 100% concordance with conventional PCR. The excellent performance of the duplex PCR assay makes it a powerful tool for surveillance of the carbapenemases NDM and KPC.
Duplex; Real-time PCR; Infection control; Carbapenemase
Multidrug resistant Pseudomonas aeruginosa harbours integrons and other mobile genetic elements such as plasmids and transposons, which easily disseminate antibiotic resistance genes among clinical strains of P. aeruginosa.
Plasmid extraction of 54 clinical isolates of P. aeruginosa was carried out by alkaline lysis method; and plasmid size estimation was done by using E. coli V517 standard plasmid marker. Fifty-four clinical strains of P. aeruginosa were isolated from 5 hospitals in 3 Southwestern states of Nigeria between March and September 2010. Plasmid extraction of isolates was carried out by alkaline lysis method; and plasmid size estimation was done by using E. coli V517 standard plasmid marker. PCR amplification for the 3 classes of resistance integrons, and gene cassette characterization were carried out using specific primers and by sequencing of PCR products. Conjugal mating of the integron positive P. aeruginosa strains with E. coli DH5α was performed to demonstrate transferability of integrons and gene cassettes.
Agarose gel electrophoresis of plasmid DNA revealed that all the 54 P. aeruginosa harboured 1–4 plasmids with sizes ranging from 2.2 – >58 kb. Class 1 integron was identified in 31 (57%) strains; but none of them carried class 2 and class 3 integrons. High prevalence of aadA gene conferring resistance to streptomycin/spectinomycin was detected in the strains positive for class 1 integron. Sequencing of the 1.6 kb and 1.2 kb amplified band of gene cassettes revealed the presence of aadA6-orfD and aadA13 respectively.
This study demonstrates the presence of plasmids and integrons harbouring resistance gene cassettes, which may collectively constitute an efficient system for dissemination of resistance genes in P. aeruginosa. Disturbingly, the rapid and unabated spread of class 1 integron-associated multidrug resistant P. aeruginosa in Southwest Nigeria may greatly hamper successful treatment of infections caused by such strains. This necessitates the establishment of functional antimicrobial resistance surveillance programmes in Nigeria.
Pseudomonas aeruginosa; Antibiotic resistance; Plasmids; Integrons; Gene cassettes
A review of the published and unpublished literature on bacterial resistance in human and animals was performed. Sixty-eight articles/reports from the Democratic Republic of Congo (DRC), Mozambique, Tanzania and Zambia were reviewed. The majority of these articles were from Tanzania. There is an increasing trend in the incidence of antibiotic resistance; of major concern is the increase in multidrug- resistant Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Vibrio cholera, non-typhoid Salmonella and other pathogens responsible for nosocomial infections. The increase in methicillin- resistant Staphylococcus aureus and extended-spectrum beta-lactamase (ESBL) producers in the countries under review confirms the spread of these clones worldwide. Clinical microbiology services in these countries need to be strengthened in order to allow a coordinated surveillance for antimicrobial resistance and provide data for local treatment guidelines and for national policies to control antimicrobial resistance. While the present study does not provide conclusive evidence to associate the increasing trend in antibiotic resistance in humans with the use of antibiotics in animals, either as feed additives or veterinary prescription, we strongly recommend a one-health approach of systematic surveillance across the public and animal health sectors, as well as the adherence to the FAO (Food and Agriculture Organization)-OIE (World Organization of animal Health) –WHO(World Health Organization) recommendations for non-human antimicrobial usage.
The present work aimed to find out the antibacterial activity of Nymphaea nouchali flower on human and plant pathogenic bacteria.
Antibacterial potency of methanol, acetone, ethyl acetate and petroleum spirit extracts of Nymphaea nouchali flower has been tested against four human pathogenic bacteria Bacillus subtilis (FO 3026) Escherichia coli (IFO 3007), Klebsiella pneumonia (ATTC 10031) and Sarcina lutea (IFO 3232) and one plant pathogenic bacterium Xanthomonas campestris (IAM 1671) by disc diffusion assay. Zone of inhibition produced by different extracts against the test bacteria was measured and compared with standard antibiotic disc.
Methanol extract possessed better antibacterial activity against two pathogenic bacteria, B. subtilis (FO 3026) and S. lutea (IFO 3232) than commercial antibiotic nalidixic acid. Acetone extract showed moderate sensitivity whereas B. subtilis (FO 3026), S. lutea (IFO 3232) and X. campestris (IAM 1671) showed resistance to ethyl acetate and petroleum spirit extracts. The minimum inhibitory concentrations of various extracts were ranged between 128–2048 μgml-1.
Nymphaea nouchali flower could be a potential candidate for future development of novel broad spectrum antibacterial herbal formulation.
Nymphaea nouchali flower; Antibacterial activity; Disc diffusion assay; Nalidixic acid
The rise of antibiotic resistance among methicillin resistant Staphylococcus aureus (MRSA), have caused concerns for the treatment of MRSA infections. Hence, search for an alternative therapy for these infections is inevitable. Folk Indian medicine refers to the use of leaf and stem bark powder of Tabernaemontana alternifolia (Roxb) in treatment of skin infections, but no scientific report establishes its antibacterial activity.
Direct aqueous extracts and sequential aqueous extracts of the stem bark of T. alternifolia (using petroleum ether and ethyl acetate as other solvents) were prepared by soxhlet extraction. The antibiotic sensitivity profiles of the clinical isolates were determined against 18 antibiotics using disc diffusion method. The isolates were identified by 16S rRNA gene sequencing. The methicillin resistance among S. aureus (MRSA) was confirmed by PCR amplification of mecA gene. The disc diffusion method was used to determine the antibacterial activity of the extracts. The micro-dilution method was used to determine the minimum inhibitory concentration (MIC) of the extract against the test organism. To further evaluate the therapeutic potential of the extract, cell cytotoxicity was checked on Vero cells by MTT assay. Chemical profiling of the extract was done by HPTLC method.
The aqueous extracts of T. alternifolia stem bark exhibited antibacterial activity against Gram-positive microorganisms, particularly against clinical isolates of MRSA and vancomycin resistant S. aureus (VRSA). The minimum inhibitory concentration (MIC) of extract against the isolates ranged from 600–800 μg/ml. The extract did not exhibit cytotoxic activity against Vero cells even at the concentration of 4 mg/ml. The chemical profiling revealed presence of alkaloids, flavonoids, coumarins, saponins and steroids. Petroleum ether and ethyl acetate extracts did not exhibit antibacterial activity.
Our results offer a scientific basis for the traditional use of T. alternifolia in the treatment of skin infections, showing that the plant extract has an enormous potential as a prospective alternative therapy against MRSA skin infections. The present study lays the basis for future studies, to validate the possible use of T. alternifolia as a candidate in the treatment of MRSA infections.
Tabernaemontana alternifolia (Roxb); Anti-MRSA; Cytotoxicity; Plant extract; Antimicrobial
Among the pregnancy urinary tract infections, asymptomatic bacteriuria (ASB) is the most common one. Untreated ASB can progress to pyelonephritis in 30-50% of the patients and can also result in prematurity in 27% of the pregnancy so it needs immediate diagnosis and treatment. In this study, we wanted to evaluate procalcitonin levels, compared to other inflammatory in pregnant women with ASB.
The study was designed between the period of January 2012 and February 2013 at Sakarya University School of Medicine, Department of Gynecology and Obstetrics. The study population included 30 pregnant patients with asymptomatic bacteriuria and 39 healthy pregnant controls.
Mean age was 28 (SD, 5.5) of the study population; mean maternal weight was 70 (SD, 8) kilogram. There were no statically significant differences between the groups according to the routine biochemical parameters, but gestational age was significantly lower in the ASB group compared to the controls (20.4 vs 28.6, respectively; p < 0.001). Serum procalcitonin levels were negative in all of the controls. In ASB group, 9 (30%) patients had procalcitonin levels greater than >0.05 ng/ml and 21(70%) patients had negative procalcitonin levels (Chi-squrae, p < 0.001). The sensitivity and specificity of procalcitonin assay for ASB was calculated as 30% and 100%, respectively. The positive predictive value was 100% and the negative predictive value was 65%. The most frequent microorganisms in the urine culture were Escherichia coli (26 patients, 87%), Proteus mirabilis (3 patients, 10%) and Klebsiella (1 patient, 3%) in the ASB group. We experienced four (44%) recurrences among nine positive procalcitonin in ASB patients after completion of treatment of the first ASB diagnosis.
Procalcitonin levels were significantly higher in ASB group than the control group and serum procalcitonin levels were higher in pregnant women with recurrent ASB. This finding is an important result revealed that high procalcitonin level can predict the further urinary tract infection risk. Finally, serum procalcitonin levels were normal in healthy pregnant women while other inflammatory markers such as WBC, ESR and CRP levels were higher.
Asymptomatic bacteriuria; Procalcitonin; Pregnant women; Inflammatory markers
The Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) was designed to monitor in vitro antimicrobial susceptibility to tigecycline and comparator agents. We present susceptibility data on Gram-negative organisms collected between 2005 and 2011 from nine United States census regions.
T.E.S.T. was conducted using standardized CLSI methodologies or FDA-approved breakpoints.
Tigecycline was highly active (MIC90 ≤ 2 mg/L) against Enterobacteriaceae irrespective of species or region of collection (N = 25011). The isolates were also highly susceptible to the carbapenems when all regional data are combined, except for ESBL-producing Klebsiella pneumoniae (MIC90 16 mg/L) and Acinetobacter baumannii (MIC90 ≥ 32 mg/L). In addition, 883 (30%) of 2900 A. baumannii isolates were classified as multidrug-resistant (MDR): these MDR organisms were most susceptible to tigecycline (MIC90 2 mg/L) and minocycline (MIC90 8 mg/L) when all regional data are considered together. Susceptibility patterns also varied widely among the regions
The findings highlight the importance of monitoring antimicrobial susceptibility patterns and implementing effective methods to curb increased resistance and also confirm that additional studies to determine the efficacy of tigecycline in vivo, especially for treating infections with MDR organisms, are warranted.
Surveillance; Tigecycline; Resistance; USA; Census regions
The aim of this study is to evaluate in-house antibiotic use in a state hospital in Turkey with its cost, using the ATC/DDD index, which is an accepted standard method.
This study was performed as a point prevalence study in a state hospital with 372 beds. All in-house patients using antibiotics on July 19, 2011 were included in the study. Indications for antibiotic use and information about the patients were recorded on special forms. Antibiotic use and cost analysis were evaluated using the ATC/DDD index, which is also suggested by the WHO to be used in similar studies.
147 patients out of 308 patients who were in-house were identified to use antibiotics with appropriate indications for prophylaxis or treatment in 61% of the patients. The rate of appropriate antibiotic use was identified to be in 78%, while this rate was 38.9% in surgical clinics. The daily cost of the antibiotics consumed on the date of the study was calculated as 4104.79 TL (=2476.80 USD).
The rate of inappropriate use of antibiotics seems to be high in our hospital. This will result in both increased costs and also increased nosocomial infection rates with resistant species. Infectious disease specialists should take more active roles in the in-house antibiotic use, hospitals should prepare and implement their own principles of antibiotic use, and microbiology laboratories should be used more effectively. These measures would decrease the conspicuous shortcomings in the antibiotic use.
Antibiotic; ATC/DDD index; Appropriate use of antibiotics
Bacterial resistance to antibiotics is growing up day by day in both community and hospital setting, with a significant impact on the mortality and morbidity rates and the financial burden that is associated. In the last two decades multi drug resistant microorganisms (both hospital- and community-acquired) challenged the scientific groups into developing new antimicrobial compounds that can provide safety in use according to the new regulation, good efficacy patterns, and low resistance profile. In this review we made an evaluation of present data regarding the new classes and the new molecules from already existing classes of antibiotics and the ongoing trends in antimicrobial development. Infectious Diseases Society of America (IDSA) supported a proGram, called “the ′10 × ´20′ initiative”, to develop ten new systemic antibacterial drugs within 2020. The microorganisms mainly involved in the resistance process, so called the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and enterobacteriaceae) were the main targets. In the era of antimicrobial resistance the new antimicrobial agents like fifth generation cephalosporins, carbapenems, monobactams, β-lactamases inhibitors, aminoglycosides, quinolones, oxazolidones, glycopeptides, and tetracyclines active against Gram-positive pathogens, like vancomycin-resistant S. aureus (VRSA) and MRSA, penicillin-resistant streptococci, and vancomycin resistant Enterococcus (VRE) but also against highly resistant Gram-negative organisms are more than welcome. Of these compounds some are already approved by official agencies, some are still in study, but the need of new antibiotics still does not cover the increasing prevalence of antibiotic-resistant bacterial infections. Therefore the management of antimicrobial resistance should also include fostering coordinated actions by all stakeholders, creating policy guidance, support for surveillance and technical assistance.
New antibiotics; Resistance; Bacteria; FDA; EMA
The presence of clinical Acinetobacter baumannii (A. baumannii) isolates with differing antibiotic resistance phenotypes in the same patient causes difficulties and confusion in treatment. This phenomenon may be caused by reasons such as cross-infection from neighboring patients that switches to different A. baumannii strain, natural mutation of A. baumannii, inducing of different antibiotic resistance genes expression or acquisition of genes conferring resistance from another source. To elucidate this question, clinical A. baumannii strains, isolated from the same individual patients, showed antibiotic resistance phenotypes switching during the same hospitalization period, were attentively collected for further analysis. Molecular approaches for phylogenetic analysis, including pulsed field gel electrophoresis, multilocus sequence typing, and short tandem repeat analysis, were employed for the chronological studies.
Our results showed that antibiotic resistance phenotype switching could have occurred as a result through both cross-infection and natural mutation roots. Our results also suggest that rapid phenotype switching between paired isolates could occur during one single course of antibiotic treatment.
Though cross infection caused antibiotic resistance phenotype switching does occur, natural mutation of A. baumannii isolates is particularly cautious for antibiotic treatment.
Acinetobacter baumannii; Pulsed field gel electrophoresis; Multilocus sequence typing; Short tandem repeat; Phenotype switch
Aquilaria crassna Pierre ex Lecomte has been traditionally used in Thailand for treatment of infectious diseases such as diarrhoea and skin diseases for a long time. The main objectives of this study were to examine antibacterial activity of the Aquilaria crassna leaf extract against Staphylococcus epidermidis and its underlying mechanism. The antioxidant activity and acute toxicity were studied as well.
Antioxidant activities were examined by FRAP, ABTS and DPPH scavenging methods. Antibacterial activity was conducted using disc diffusion assay and the minimum inhibitory concentration (MIC) was determined by dilution method. The minimum bactericidal concentration (MBC) was reported as the lowest concentration producing no growth of microbes in the subcultures. Morphological changes of the microbe were observed by scanning electron microscopy, while an inhibitory effect on biofilm formation was evaluated by phase contrast microscopic analysis. Bacterial cell wall integrity was assessed by transmission electron microscopy. Acute toxicity was conducted in accordance with the OECD for Testing of Chemicals (2001) guidelines.
The extract exhibited considerable antioxidant activity. Staphylococcus epidermidis was susceptible to the extract with the MIC and MBC of 6 and 12 mg/ml, respectively. The extract caused swelling and distortion of bacterial cells and inhibited bacterial biofilm formation. Rupture of bacterial cell wall occurred after treated with the extract for 24 h. Acute toxicity test in mice showed no sign of toxicity or death at the doses of 2,000 and 15,000 mg/kg body weight.
The aqueous extract of Aquilaria crassna leaves possesses an in vitro antibacterial activity against Staphylococcus epidermidis, with no sign of acute oral toxicity in mice, probably by interfering with bacterial cell wall synthesis and inhibiting biofilm formation.
Aquilaria crassna; Staphylococcus epidermidis; Antioxidant; Anitbacterials; Cell wall; Acute toxicity
Tigecycline shows great antimicrobial activity against both Gram-positive and Gram-negative bacteria, and has been considered to be an appropriate choice in controlling infection caused by multi-drug resistant (MDR) pathogens, such as carbapenemase-producing Enterobacteriaceae (CPE). Although many clinical trials evaluate the efficacy and safety of tigecycline on adults, rare reports recommend tigecycline to treat pediatric patient. In this study, we presented a clinical case with tigecycline as an anti-infectious agent on a 14-year-old child who was suffering from infection of intraperitoneal abscess caused by Klebsiella pneumoniae carbapenemases (KPC)-producing Escherichia coli with extreme drug resistant profile. By accessing the clinical outcome and efficacy of the patient, and the side effects of tigecycline, our research explored the documented experience of tigecycline on controlling infection caused by CPE isolate in children.
Tigecycline; Treatment; KPC; Pediatric patient
Streptococcal superantigens (SAgs) are the major virulence factors of infection in humans for group A Streptococcus (GAS) bacteria. A panel consisting of seven duplex real-time PCR assays was developed to simultaneously detect 13 streptococcal SAgs and one internal control which may be important in the control of GAS-mediated diseases.
Primer and probe sequences were selected based on the highly conserved region from an alignment of nucleotide sequences of the 13 streptococcal SAgs. The reaction conditions of the duplex real-time PCR were optimized and the specificity of the duplex assays was evaluated using SAg positive strains. The limit of detection of the duplex assays was determined by using 10-fold serial dilutions of the DNA of 13 streptococcal SAgs and compared to a conventional polymerase chain reaction (PCR) method for evaluating the duplex assays sensitivity.
Using the duplex assays, we were able to differentiate between 13 SAgs from Streptococcus strains and other non-Streptococcus bacteria without cross-reaction. On the other hand, the limit of detection of the duplex assays was at least one or two log dilutions lower than that of the conventional PCR.
The panel was highly specific (100%) and the limit of detection of these duplex groups was at least ten times lower than that obtained by using a conventional PCR method.
Streptococcal; Superantigens; Duplex real-time PCR
The term ’Multidrug-resistant’ (MDR) applies to a bacterium that is simultaneously resistant to a number of antimicrobials belonging to different chemical classes. The effectiveness of currently available antmicrobial drugs is decreasing due to the increasing number of resistant strains causing infections so that available therapeutic options for such organisms are severely limited.
The aim of this study was to determine multidrug-resistance rate of bacterial isolates that caused wound infections.
A Hospital based cross-sectional study was conducted on 322 wound samples taken from consecutive patients seen at inpatient and outpatient department of Jimma University Specialized Hospital from June to December 2011. Swabs from surgical incisions, burns, abscess and traumatic wounds were collected aseptically using Levine’s technique. Bacteriological culture and examination was done following standard microbiological techniques. Multidrug-resistance test was performed by disk diffusion method against 10 classes of antimicrobials. The data was analyzed for descriptive statistics using SPSS version 16 and Microsoft Excel.
The overall MDR among gram positive and gram negative bacterial isolates were (77%) and (59.3%) respectively. About, 86.2% S.aureus and 28.6% of Coagulase negative Staphylococci became MDR. Nearly 30.1% of S.aureus was resistant to six classes of antimicrobials. The average MDR rate of Proteus, Klebsiella, and Providencia species was 74.8%, 69.6% and 75% in that order. Nearly, 30.8% of Proteus sp, 32.6% of Klebsiella sp and 61% of Citrobacter sp were resistance to 4 classes each. Surprisingly, the average MDR rate for Citrobacter sp was 100%. About (76.7%) of S.aureus was Oxacillin/Methicillin resistant while (16.4%) were Vancomycin resistant. Proteus species was the predominant isolates (27.9%) followed by P.aeruginosa and S.aureus (19.3%) and (19%) respectively.
This study indicated that, the overall rate of MDR bacterial pathogens that caused wound infection was very high and many of the isolates were also identified as resistant to three or more classes of antimicrobials. Such widespread resistance to antimicrobial classes is something serious because a few treatment options remain for patients with wound infections. Periodic monitoring of etiology and antimicrobial susceptibility in areas where there is no culture facility is essential to assists physician in selection of chemotherapy.
Multi drug resistance; Wound infection; Jimma; Ethiopia
Klebsiella pneumoniae outbreaks possessing extended-spectrum β-lactamase- (ESBL) mediated resistance to third-generation cephalosporins have increased significantly in hospital and community settings worldwide. The study objective was to characterize prevalent genetic determinants of TEM, SHV and CTX-M types ESBL activity in K. pneumoniae isolates from Egypt.
Sixty five ESBL-producing K. pneumoniae strains, isolated from nosocomial and community-acquired infections from 10 Egyptian University hospitals (2000–2003), were confirmed with double disc-synergy method and E-test. blaTEM, blaSHV and blaCTX-m genes were identified by PCR and DNA sequencing. Pulsed-field gel electrophoresis (PFGE) was conducted for genotyping.
All isolates displayed ceftazidime and cefotaxime resistance. blaTEM and blaSHV genes were detected in 98% of the isolates’ genomes, while 11% carried blaCTX-m. DNA sequencing revealed plasmid-borne SHV-12,-5,-2a (17%), CTX-m-15 (11%), and TEM-1 (10%) prevalence. Among SHV-12 (n=8), one isolate displayed 100% blaSHV-12 amino acid identity, while others had various point mutations: T17G (Leu to Arg, position 6 of the enzyme: n=2); A8T and A10G (Tyr and Ile to Phe and Val, positions 3 and 4, respectively: n=4), and; A703G (Lys to Glu 235: n=1). SHV-5 and SHV-2a variants were identified in three isolates: T17G (n=1); A703G and G705A (Ser and Lys to Gly and Glu: n=1); multiple mutations at A8T, A10G, T17G, A703G and G705A (n=1). Remarkably, 57% of community-acquired isolates carried CTX-m-15. PFGE demonstrated four distinct genetic clusters, grouping strains of different genetic backgrounds.
This is the first study demonstrating the occurrence of SHV-12, SHV-5 and SHV-2a variants in Egypt, indicating the spread of class A ESBL in K. pneumoniae through different mechanisms.
Resistance rates to polymyxin B in surveillance studies have been very low despite its increasing use worldwide as the last resort therapy for multidrug-resistant Gram-negative bacilli. However, two other resistance phenotypes, hetero- and adaptive resistance, have been reported to polymyxin. We aimed to investigate the presence of polymyxin B hetero- and adaptive resistance and evaluate its stability in carbapenem-resistant Acinetobacter baumannii (CRAB) clinical isolates.
CRAB isolates were recovered from hospitalized patients at three Brazilian hospitals. Hetero-resistance was determined by population analysis profile (PAP). Adaptive resistance was evaluated after serial daily passages of isolates in Luria-Bertani broth containing increasing polymyxin B concentrations. MICs of polymyxin B of colonies growing at the highest polymyxin B concentration were further determined after daily sub-cultured in antibiotic-free medium and after storage at −80°C, in some selected isolates.
Eighty OXA-23-producing CRAB isolates were typed resulting in 15 distinct clones. Twenty-nine randomly selected isolates (at least one from each clone) were selected for hetero- resistance evaluation: 26 (90%) presented growth of subpopulations with higher polymyxin B MIC than the original one in PAP. No isolate has grown at polymyxin B concentrations higher than 2 mg/L. Polymyxin B MICs of subpopulations remained higher than the original population after daily passages on antibiotic-free medium but returned to the same or similar levels after storage. Twenty-two of the 29 isolates (at least one from each clone) were evaluated for adaptive resistance: 12 (55%) presented growth in plates containing 64 mg/L of polymyxin B. Polymyxin B MICs decreased after daily passages on antibiotic-free medium and returned to the same levels after storage.
The presence of subpopulations with higher polymyxin B MIC was extremely common and high-level adaptive resistance was very frequent in CRAB isolates.
Acinetobacter baumannii; Polymyxins; Polymyxin B; Colistin; Hetero-resistance; Adaptive resistance; Multidrug-resistance; Carbapenemase
Sida urens L. (Malvaceae) is in flora of Asian medicinal herbs and used traditionally in West of Burkina Faso for the treatment of infectious diseases and particularly used against, dental caries bacteria, fever, pain and possesses analgesic properties. This study was conducted to reveal the antibacterial effect against dental caries bacteria on the one hand, and evaluate their analgesic capacity in experimental model with Swiss mice and on the other hand, with an aim to provide a scientific basis for the traditional use of this plant for the management of dental caries bacteria.
The antibacterial assays in this study were performed by using inhibition zone diameters, MIC (Minimum inhibitory concentration) and MBC (Minimal bactericidal concentration) methods. On the whole the dental caries bacteria (Gram-positive and Gram-negative bacterial strains) were used. Negative control was prepared using discs impregnated with 10% DMSO in water and commercially available Gentamicin from Alkom Laboratories LTD was used as positive reference standards for all bacterial strains. In acute toxicity test, mice received doses of extract (acetone/water extract) from Sida urens L. by intraperitoneal route and LD50 was determined in Swiss mice. As for analgesic effects, acetic acid writhing method was used in mice. The acetic acid-induced writhing method was used in mice with aim to study analgesic effects.
The results showed that the highest antibacterial activities were founded with the polyphenol-rich fractions against all bacterial strains compared to the standard antibiotic. About preliminary study in acute toxicity test, LD50 value obtained was more than 5000 mg/kg b.w. Polyphenol-rich fractions produced significant analgesic effects in acetic acid-induced writhing method and in a dose-dependent inhibition was observed.
These results validate the ethno-botanical use of Sida urens L. (Malvaceae) and demonstrate the potential of this herbaceous as a potential antibacterial agent of dental caries that could be effectively used for future health care purposes.
Fever of undetermined origin always poses a challenging problem to the physician. Tuberculosis is an important health problem in developing countries. It is mostly seen in immune-compromised patients. And it is one of the common causes of fever of unknown origin. I am reporting a case of a splenic tuberculosis in 48 years old male who is not known of any immune deficiency state, he was presented with 3 weeks history of fever and found to have severe neutropenia and with negative work up for all hematological, rheumatological and malignant causes. A computerized tomography scan of the abdomen confirmed splenic enlargement with multiples hypo dense lesions consist with either splenic infection or splenic lymphoma so exploratory splenectomy was performed. Histological examination revealed granulomatouse inflammation with numerous acid fast bacilli consist with tuberculosis. He was started on four anti-tuberculouse drugs. in less than one week his fever subside with normalization of his neutrophilic count
Splenic tuberculosis; Fever of unknown origin; Severe neutropenia
The emergence of multidrug-resistant bacteria is a world health problem. Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) strains, is one of the most important human pathogens associated with hospital and community-acquired infections. The aim of this work was to evaluate the antibacterial activity of a Pseudomonas aeruginosa-derived compound against MRSA strains.
Thirty clinical MRSA strains were isolated, and three standard MRSA strains were evaluated. The extracellular compounds were purified by vacuum liquid chromatography. Evaluation of antibacterial activity was performed by agar diffusion technique, determination of the minimal inhibitory concentration, curve of growth and viability and scanning electron microscopy. Interaction of an extracellular compound with silver nanoparticle was studied to evaluate antibacterial effect.
The F3 (ethyl acetate) and F3d (dichloromethane- ethyl acetate) fractions demonstrated antibacterial activity against the MRSA strains. Phenazine-1-carboxamide was identified and purified from the F3d fraction and demonstrated slight antibacterial activity against MRSA, and synergic effect when combined with silver nanoparticles produced by Fusarium oxysporum. Organohalogen compound was purified from this fraction showing high antibacterial effect. Using scanning electron microscopy, we show that the F3d fraction caused morphological changes to the cell wall of the MRSA strains.
These results suggest that P. aeruginosa-produced compounds such as phenazines have inhibitory effects against MRSA and may be a good alternative treatment to control infections caused by MRSA.
Antibacterial activity; Methicillin-resistant; Pseudomonas aeruginosa; Staphylococcus aureus
Staphylococcus aureus infections are increasingly reported from both health institutions and communities around the world. In particular, infections due to methicillin-resistant Staphylococcus aureus (MRSA) strains have been detected worldwide. If MRSA becomes the most common form of S. aureus in a community, it makes the treatment of common infections much more difficult. But, report on the current status of community acquired MRSA in the study area is scanty.
Community-based cross sectional study was conducted to evaluate the current prevalence and antibiotic susceptibility pattern of MRSA among primary school children and prisoners in Jimma town. MRSA was detected using Cefoxitin (30μg) disc; and epidemiologic risk factors were assessed using pre-designed questionnaires distributed to the children’s parents and prisoners. A total of 354 nasal swabs were collected from primary school children and prisoners from December 2010 to March 2011 following standards microbiological methods.
A total of 169 S. aureus isolates were recovered. The overall prevalence of MRSA among the study population was 23.08 % (39/169). Specifically, the prevalence of MRSA among primary school children and prisoners were 18.8% (27/144) and 48% (12/25), respectively. The isolated S. aureus and MRSA displayed multiple drug resistance (MDR) to 2 to 10 antibiotics. The most frequent MDR was Amp/Bac/Ery/Pen/Fox (resistance to Ampicillin, Bacitracin, Erythromycin, Penicillin, and Cefoxitin).
The present study revealed that MRSA could be prevalent in the healthy community, transmitted from hospital to the community. The high distribution of MRSA could be favored by potential risk factors. Thus, for comprehensive evaluation of the current prevalence of MRSA and design control measures, consideration need to be given to the healthy community besides data coming from health institutions.
CA-MRSA; Drug resistance; Ethiopia; HA-MRSA; Prevalence; Risk factor; S. aureus
Central line-associated bloodstream infections (CLABs) have long been associated with excess lengths of stay, increased hospital costs and mortality attributable to them. Different studies from developed countries have shown that practice bundles reduce the incidence of CLAB in intensive care units. However, the impact of the bundle strategy has not been systematically analyzed in the adult intensive care unit (ICU) setting in developing countries, such as Turkey. The aim of this study is to analyze the impact of the International Nosocomial Infection Control Consortium (INICC) multidimensional infection control approach to reduce the rates of CLAB in 13 ICUs of 13 INICC member hospitals from 8 cities of Turkey.
We conducted active, prospective surveillance before-after study to determine CLAB rates in a cohort of 4,017 adults hospitalized in ICUs. We applied the definitions of the CDC/NHSN and INICC surveillance methods. The study was divided into baseline and intervention periods. During baseline, active outcome surveillance of CLAB rates was performed. During intervention, the INICC multidimensional approach for CLAB reduction was implemented and included the following measures: 1- bundle of infection control interventions, 2- education, 3- outcome surveillance, 4- process surveillance, 5- feedback of CLAB rates, and 6- performance feedback on infection control practices. CLAB rates obtained in baseline were compared with CLAB rates obtained during intervention.
During baseline, 3,129 central line (CL) days were recorded, and during intervention, we recorded 23,463 CL-days. We used random effects Poisson regression to account for clustering of CLAB rates within hospital across time periods. The baseline CLAB rate was 22.7 per 1000 CL days, which was decreased during the intervention period to 12.0 CLABs per 1000 CL days (IRR 0.613; 95% CI 0.43 – 0.87; P 0.007). This amounted to a 39% reduction in the incidence rate of CLAB.
The implementation of multidimensional infection control approach was associated with a significant reduction in the CLAB rates in adult ICUs of Turkey, and thus should be widely implemented.
Catheter related infections; Central line-associated bloodstream infection; Device-associated infections; Healthcare-associated infections; Bundle; International nosocomial infection control consortium; Multidimensional approach; Hand hygiene; Developing countries; Limited-resource countries
Shigella flexneri serotype 1c emerged as a critical isolate from children in Egypt and Pakistan. The pattern of antimicrobial susceptibility (AMS) and resistance genes of this serotype have yet to be characterized.
Sixty nine S. flexneri 1c isolates isolates were identified from both Egypt (n-46) and Pakistan (n = 23) and tested for AMS by disk diffusion method and minimal inhibitory concentrations were also determined. Isolates were genotyped by pulsed field gel electrophoresis (PFGE) and five relevant resistance genes (blaTEM, blaSHV, blaOXA, sulI and sulII) were detected by polymerase chain reaction (PCR) and confirmed by DNA sequencing. High resistance was observed in all isolates for ampicillin (AM >96%); trimethoprim-sulphamethoxazole and tetracycline (>88%). Most AM-resistant isolates from Egypt (70%) harbored blaTEM resistance, while 52% of isolates from Pakistan expressed blaOXA. All isolates were closely related by PFGE, irrespective of source or time of collection. The sulII gene was present in 100% of isolates from pediatric cases in Egypt, 65% of Pakistan isolates, and 53% of isolates from older Egyptian patients.
While different Shigella serotypes gathered in specific genotypic groups, 1c serotype isolates formed multiple clusters. Although AMS was considerably high to most commonly used drugs, genetic determinants were variable between countries over time. The data stress the need for a more careful selection of antibiotics in the treatment of shigellosis.
S. flexneri 1c; Genetic diversity; Antibiotic resistance; Oxa1; PFGE; Egypt; Diarrhea; Pakistan
Urinary tract infections (UTIs) are one of the most common bacterial infections with global expansion. These infections are predominantly caused by uropathogenic Escherichia coli (UPEC).
Totally, 123 strains of Escherichia coli isolated from UTIs patients, using bacterial culture method were subjected to polymerase chain reactions for detection of various O- serogroups, some urovirulence factors, antibiotic resistance genes and resistance to 13 different antibiotics.
According to data, the distribution of O1, O2, O6, O7 and O16 serogroups were 2.43%, besides O22, O75 and O83 serogroups were 1.62%. Furthermore, the distribution of O4, O8, O15, O21 and O25 serogroups were 5.69%, 3.25%, 21.13%, 4.06% and 26.01%, respectively. Overall, the fim virulence gene had the highest (86.17%) while the usp virulence gene had the lowest distributions of virulence genes in UPEC strains isolated from UTIs patients. The vat and sen virulence genes were not detected in any UPEC strains. Totally, aadA1 (52.84%), and qnr (46.34%) were the most prevalent antibiotic resistance genes while the distribution of cat1 (15.44%), cmlA (15.44%) and dfrA1 (21.95%) were the least. Resistance to penicillin (100%) and tetracycline (73.98%) had the highest while resistance to nitrofurantoin (5.69%) and trimethoprim (16.26%) had the lowest frequencies.
This study indicated that the UPEC strains which harbored the high numbers of virulence and antibiotic resistance genes had the high ability to cause diseases that are resistant to most antibiotics. In the current situation, it seems that the administration of penicillin and tetracycline for the treatment of UTIs is vain.
Escherichia coli; Urinary tract infections; Serogroups; Virulence factors; Antibiotic resistance