Evaluating decontamination protocols for the isolation of Mycobacterium ulcerans from swabs

Mycobacterium ulcerans (M. ulcerans) is the causative agent of Buruli Ulcer (BU) disease. In order to inhibit the growth of the microbial contaminants during culture of M. ulcerans, it is necessary to decontaminate BU samples with effective chemical agents. This study aimed at investigating some selected chemicals as potential decontamination agents for the isolation of M. ulcerans from swabs.; Povidone iodine at 0.5 and 1% exhibited the lowest contamination and recovery rate for microbial contaminants and M. ulcerans. The most effective decontamination method was the protocol using 2% cetylpyridinium chloride/4% sodium chloride (recovery rate = 53%, contamination rate = 14%). The observed difference between the recovery rate of 2% CPC/4% NaC and the other protocols was however not statistically significant (p = 0.76).; Two percent (2%) cetylpyridinium chloride/4% sodium chloride can be conveniently used as an alternative decontamination method for the isolation of M. ulcerans from swabs

Neonatal bloodstream infections in a Ghanaian Tertiary Hospital:Are the current antibiotic recommendations adequate?

Abstract Background Diagnosis of bloodstream infections (BSI) in neonates is usually difficult due to minimal symptoms at presentation; thus early empirical therapy guided by local antibiotic susceptibility profile is necessary to improve therapeutic outcomes. Methods A review of neonatal blood cultures submitted to the microbiology department of the Korle-Bu Teaching Hospital was conducted from January 2010 through December 2013. We assessed the prevalence of bacteria and fungi involved in BSI and the susceptibility coverage of recommended empiric antibiotics by Ghana Standard Treatment guidelines and the WHO recommendations for managing neonatal sepsis. The national and WHO treatment guidelines recommend either ampicillin plus gentamicin or ampicillin plus cefotaxime for empiric treatment of neonatal BSI. The WHO recommendations also include cloxacillin plus gentamicin. We described the resistance profile over a 28-day neonatal period using multivariable logistic regression analysis with linear or restricted cubic splines. Results A total of 8,025 neonatal blood culture reports were reviewed over the four-year period. Total blood culture positivity was 21.9 %. Gram positive organisms accounted for most positive cultures, with coagulase negative staphylococci (CoNS) being the most frequently isolated pathogen in early onset infections (EOS) (59.1 %) and late onset infections (LOS) (52.8 %). Susceptibility coverage of early onset bacterial isolates were 20.7 % to ampicillin plus cefotaxime, 32.2 % to the combination of ampicillin and gentamicin, and 71.7 % to cloxacillin plus gentamicin. For LOS, coverage was 24.6 % to ampicillin plus cefotaxime, 36.2 % to the combination ampicillin and gentamicin and 63.6 % to cloxacillin plus gentamicin. Cloxacillin plus gentamicin remained the most active regimen for EOS and LOS after exclusion of BSI caused by CoNS. For this regimen, the adjusted odds of resistance decreased between 12-34 % per day from birth to day 3 followed by the slowest rate of resistance increase, compared to the other antibiotic regimen, thereafter until day 28. The trend in resistance remained generally unchanged after excluding data from CoNS. Multidrug resistant isolates were significantly (p-value <0.001) higher in LOS (62.4 %, n = 555/886) than in EOS (37.3 %, n = 331/886). Conclusions There is low antibiotic susceptibility coverage for organisms causing neonatal bloodstream infections in Korle-Bu Teaching Hospital when the current national and WHO recommended empiric antibiotics were assessed. A continuous surveillance of neonatal BSI is required to guide hospital and national antibiotic treatment guidelines for neonatal sepsis

Quinolone resistance in Escherichia coli from Accra, Ghana

<p>Abstract</p> <p>Background</p> <p>Antimicrobial resistance is under-documented and commensal <it>Escherichia coli </it>can be used as indicator organisms to study the resistance in the community. We sought to determine the prevalence of resistance to broad-spectrum antimicrobials with particular focus on the quinolones, which have recently been introduced in parts of Africa, including Ghana.</p> <p>Results</p> <p>Forty (13.7%) of 293 <it>E. coli </it>isolates evaluated were nalidixic acid-resistant. Thirteen (52%) of 2006 and 2007 isolates and 10 (66.7%) of 2008 isolates were also resistant to ciprofloxacin. All but one of the quinolone-resistant isolates were resistant to three or more other antimicrobial classes. Sequencing the quinolone-resistance determining regions of <it>gyrA </it>and <it>parC</it>, which encode quinolone targets, revealed that 28 quinolone-resistant <it>E. coli </it>harboured a substitution at position 83 of the <it>gyrA </it>gene product and 20 of these isolates had other <it>gyrA </it>and/or <it>parC </it>substitutions. Horizontally-acquired quinolone-resistance genes <it>qnrB1</it>, <it>qnrB2</it>, <it>qnrS1 </it>or <it>qepA </it>were detected in 12 of the isolates. In spite of considerable overall diversity among <it>E. coli </it>from Ghana, as evaluated by multilocus sequence typing, 15 quinolone-resistant <it>E. coli </it>belonged to sequence type complex 10. Five of these isolates carried <it>qnrS1 </it>alleles.</p> <p>Conclusions</p> <p>Quinolone-resistant <it>E. coli </it>are commonly present in the faecal flora of Accra residents. The isolates have evolved resistance through multiple mechanisms and belong to very few lineages, suggesting clonal expansion. Containment strategies to limit the spread of quinolone-resistant <it>E. coli </it>need to be deployed to conserve quinolone effectiveness and promote alternatives to their use.</p

Prevalence and characterization of Salmonella among humans in Ghana

BACKGROUND: Non-typhoidal Salmonella (NTS) is a public health problem worldwide and particularly in Africa with high disease burden. This study characterized Salmonella isolates from humans in Ghana to determine serovar distribution, phage types, and antimicrobial resistance. Further, the clonal relatedness among isolates was determined. METHODS: One hundred and thirty-seven Salmonella isolates (111 clinical and 26 public toilet) were characterized using standard serotyping, phage typing, and antimicrobial susceptibility testing methods. The molecular epidemiology of common serovars (Salmonella Typhimurium and Salmonella Enteritidis) was established by pulsed field gel electrophoresis (PFGE). RESULTS: Twenty-two serovars were identified with S. Enteritidis, S. Typhimurium, and Salmonella Derby as the most dominant. One hundred and twelve isolates showed resistance to more than one antimicrobial. Fifty-eight (n = 58/112; 54.5%) strains were multi-resistant with low resistance to cephalosporins ceftazidime (8.0%), cefotaxime (4.5%), and cefoxitin (2.7%) with synergy to clavulanic acid indicating possible ESBLs. Isolates showed high resistance to trimethoprim (66.1%), tetracycline (61.6%), ampicillin (57.1%), sulfamethoxazole (46.4%), chloramphenicol (33.9%), and ciprofloxacin (25.0%). The most common resistance pattern of multi-resistant serovars was to ampicillin, chloramphenicol, sulphonamide, and trimethoprim. S. Enteritidis (18/43) strains reacted with typing phages but did not conform to any phage type with PT14B and PT4 as predominant definitive phage types. Six S. Typhimurium strains reacted but did not conform to any recognized phage type while seven were non-typable. The predominant definitive phage types were DT1 and DT22. PFGE patterns of human S. Enteritidis were closely related to patterns of poultry isolates obtained in a previous study in Ghana. CONCLUSIONS: Cephalosporin resistance is uncommon among Salmonella from humans in Ghana. Poultry may be an important source of human salmonellosis. There is an urgent need for the implementation of routine surveillance of antimicrobial use and bacterial resistance among humans in Ghana

Susceptibility Profiles of Mycobacterium ulcerans

Background. Drug resistance is a major challenge in antibiotic chemotherapy. Assessing resistance profiles of pathogens constitutes an essential surveillance tool in the epidemiology and control of infectious diseases, including Buruli ulcer (BU) disease. With the successful definitive management of BU using rifampicin and streptomycin, little attention had been paid to monitoring emergence of resistant Mycobacterium ulcerans (M. ulcerans) isolates in endemic communities. This study investigated the susceptibility profiles of M. ulcerans isolates from two BU endemic areas in Ghana to streptomycin and rifampicin. Methods. The antibiotic susceptibility of seventy (70) M. ulcerans isolates to rifampicin and streptomycin was determined simultaneously at critical concentrations of 40 µg/mL and 4 µg/mL, respectively, by the Canetti proportion method. Results. Resistance to rifampicin was observed for 12 (17.1%) M. ulcerans isolates tested, whilst 2 (2.9%) showed resistance to streptomycin. None of the isolates tested showed dual resistance to both rifampicin and streptomycin. Conclusion. Outcomes from this study may not be reflective of all BU endemic communities; it, however, provides information on the resistance status of the isolates, which is useful for monitoring of M. ulcerans, as well as BU disease surveillance and control

Physicians' knowledge, attitudes, and perceptions concerning antibiotic resistance:a survey in a Ghanaian tertiary care hospital

Abstract Background Understanding the knowledge, attitudes and practices of physicians towards antibiotic resistance is key to developing interventions aimed at behavior change. The survey aimed to investigate physicians’ knowledge and attitudes towards antibiotic resistance in a tertiary-care hospital setting in Ghana. Methods We conducted a cross-sectional respondent-driven survey using a 40-item, anonymous, voluntary, traditional paper-and-pencil self-administered questionnaire among 159 physicians at Korle-Bu Teaching Hospital. Single and multi-factor analysis were conducted to assess the study objectives. Results The survey was completed by 159 of 200 physicians (response rate of 79.5%). Of physicians, 30.1% (47/156) perceived antibiotic resistance as very important global problem, 18.5% (29/157) perceived it as very important national problem and only 8.9% (14/157) thought it as a very important problem in their hospital. Methicillin resistant Staphylococcus aureus was the most known about antibiotic resistant bacteria of public health importance followed by extended-spectrum beta-lactamase-producing Enterobacteriaceae, carbapenem resistant Enterobacteriaceae (CRE) and vancomycin resistant enterococci (VRE). In multiple logistic regression analysis, senior physicians were nearly 3 times more likely to know about CRE than junior physicians. The odds of knowing about VRE increased over 4.5 times from being a junior to becoming senior physician. Among junior physicians, age had no associated effect on their knowledge of VRE or CRE. Conclusions Physicians in this survey showed variable knowledge and perceptions on antibiotic resistance. Introducing educational programs on antibiotic resistance would be a useful intervention and should focus on junior physicians

Regional Dissemination of a Trimethoprim-Resistance Gene Cassette via a Successful Transposable Element

Antimicrobial resistance is a growing international problem. We observed a 50% increase in the prevalence of trimethoprim resistance among fecal Escherichia coli from healthy Nigerian students between 1998 and 2005, a trend to increase that continued in 2009.A PCR-based screen revealed that 131 (43.1%) of isolates obtained in Nigeria in 2005 and 2009 carried integron-borne dfrA cassettes. In the case of 67 (51.1%) of these isolates, the cassette was a class 1-integron-borne dfrA7 gene, which has been reported at high prevalence from E. coli isolates from other parts of Africa. Complete sequencing of a 27 Kb dfrA7-bearing plasmid from one isolate located the dfrA7 gene within a Tn21-type transposon. The transposon also contained an IS26-derived bla/sul/str element, encoding resistance to β-lactams, sulphonamides and streptomycin, and mercury resistance genes. Although the plasmid backbone was only found in 12 (5.8%) of trimethoprim-resistant isolates, dfrA7 and other transposon-borne genes were detected in 14 (16.3%) and 32 (26.3%) of trimethoprim resistant isolates collected in Nigeria in 2005 and 2009, respectively. Additionally, 37 (19.3%) of trimethoprim-resistant E. coli isolates collected between 2006 and 2008 from Ghana were positive for the dfrA7 and a transposon marker, but only 4 (2.1%) harbored the plasmid backbone.Our data point to transposition as a principal mechanism for disseminating dfrA7 among E. coli from Nigeria and Ghana. On-going intensive use of the affordable broad-spectrum antibacterials is likely to promote selective success of a highly prevalent transposable element in West Africa