Beta-lactamase resistance genes in Enterobacteriaceae from Nigeria

Background

Beta-lactamase genes are one of the most important groups of antimicrobial resistance genes in human and animal health. Therefore, continuous surveillance of this group of resistance genes is needed for a better understanding of the local epidemiology within a country and global dissemination.

Aim

This review was carried out to identify different beta-lactamase resistance genes reported in published literature from Nigeria.

Methods

Systematic review and meta-analysis was carried out on eligible Nigerian articles retrieved from electronic literature searches of PubMed^®, African Journals Online, and Google Scholar published between January 1990 and December 2019. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses method was adopted to facilitate clarity and transparency in reporting review findings.

Results

Fifty-seven articles were included. All beta-lactamases reported were detected from Gram-negative bacteria, particularly from Enterobacteriaceae. Thirty-six different beta-lactamase genes were reported in Nigeria. These genes belong to the narrow-spectrum, AmpC, extended-spectrum and carbapenemase beta-lactamase resistance genes. The pooled proportion estimate of extended-spectrum beta-lactamase genes in Nigeria was 31% (95% confidence interval [CI]: 26% – 36%, p < 0.0001), while the estimate of the bla_CTX-M-15 gene in Nigeria was 46% (95% CI: 36% – 57%, p < 0.0001). The proportion estimate of AmpC genes was 32% (95% CI: 11% – 52%, p < 0.001), while the estimate for carbapenemases was 8% (95% CI: 5% – 12%, p < 0.001).

Conclusion

This study provides information on beta-lactamase distribution in Nigeria. This is necessary for a better understanding of molecular epidemiology of clinically important beta-lactamases, especially the extended-spectrum beta-lactamases and carbapenemases in Nigeria.

Multi-Drug Resistant Escherichia coli, Biosecurity and Anti-Microbial Use in Live Bird Markets, Abeokuta, Nigeria

Live bird markets (LBM) remain a critical link from farm to fork in the poultry value chain, which oftentimes promotes indiscriminate antimicrobial use (AMU) and resistance (AMR). In this study, we assessed biosecurity practices, AMU, and associated these with multidrug resistant (MDR) E. coli in LBMs in Abeokuta, Ogun State. A cross-sectional survey among live bird sellers (LBS) in eight LBMs was conducted using a semi-structured questionnaire. Also, cloacal samples (n = 200) were randomly collected and pooled for bacteriological detection of MDR E. coli in live chickens of consenting LBS. Susceptibility to 14 antimicrobials belonging to 6 different classes was determined using the disk diffusion method. Biosecurity level and AMU were generally low. LBS less than 46 years were 6.8- fold more likely to fall within the poor biosecurity level (Crudes odds ratio = 6.8; 95% CI; 1.20-38.56; p = 0.03) than others. An informal or primary school education increased the odds of having a poor practice of AMU by 15.1 folds (Crudes odds ratio = 15.1; 95% CI; 2.73-84.18; p = 0.002) than those with secondary or tertiary. The prevalence of E. coli and MDR E. coli at the LBM level were 80% and 56.3%, respectively. Extremely high resistance rates were observed for ceftazidime (96.9%) and imipenem (90.6%). The odds of MDR E. coli increased eight-fold in poultry kept by LBS who use AMs as prophylaxis. This current data could be useful for the development of targeted behavioral risk communication and mitigation strategies for AMR to impede the potential horizontal transfer of AMR genes to humans through animal-sourced food.

Systematic review and meta-analysis of veterinary-related occupational exposures to hazards

Understanding hazards within the veterinary profession is critical for developing strategies to ensure the health and safety of personnel in the work environment. This study was conducted to systematically review and synthesize data on reported risks within veterinary workplaces. A systematic review of published data on occupational hazards and associated risk factors were searched within three database platforms namely PubMed, Ebscohost, and Google scholar. To determine the proportion estimates of hazards and pooled odds ratio, two random-effects meta-analysis were performed. For the biological, chemical and physical hazards, the pooled proportion estimates were 17% (95% CI: 15.0-19.0, p < 0.001), 7.0% (95% CI: 6.0-9.0%, p < 0.001) and 65.0% (95% CI: 39.0-91.0%, p < 0.001) respectively. A pooled odds ratio indicated the risk of exposures to physical (OR=1.012, 95% CI: 1.008-1.017, p < 0.001) and biological hazards (OR=2.07, 95% CI: 1.70-2.52, p <0.001) increased when working or in contact with animals. The review has provided a better understanding of occupational health and safety status of veterinarians and gaps within the developing countries. This evidence calls for policy formulation and implementation to reduce the risks of exposures to all forms of occupational-related hazards in veterinary workplaces.

Development of a fixation-free fluorescence in situ hybridization for the detection of Salmonella species

Salmonella is one of the most important infectious bacteria causing severe gastroenteritis and deaths in humans and animals, and the prompt diagnosis is crucial for effective control and treatment. The detection of Salmonella still depends principally on culture-based methods, which is time-consuming and laborious. Recently, polyhexamethylene biguanide (PHMB) was discovered to have cellular delivery properties and its combination with the fluorescence in situ hybridization (FISH) method was exploited for oligomer delivery and the rapid detection of Salmonella spps in this study. Cell-associated fluorescence was quantified using Volocity^® 3-D image analysis software (Volocity 6.3, PerkinElmer, Inc.). PHMB complexed with fluorophore-labelled species-specific oligomers permeabilized freshly grown viable strains of Salmonella cells and mediated strong cell-associated fluorescence signals. This strategy further enabled a fixation-free protocol and hybridization in a single reaction. Using the modified FISH method, monoculture Salmonella strains were validated as well as detected in artificially contaminated water and milk within a turnaround period of 5 h. The method was observed to be comparable with the standard FISH technique (sFISH; P > 0.05). The findings suggest that fixation-free delivery and hybridization of oligomers using PHMB can provide a simplified and prompt strategy for Salmonella detection at the species level, and promote early management responses to the disease and appropriate antimicrobial therapy.

Assessment of the Biorisk Status of Veterinary Laboratories in Southwest Nigeria: Application of the Food and Agriculture Organization Laboratory Mapping Tool-Safety Module

Introduction

Because of the nature of work conducted in veterinary laboratories and potential exposures to pathogenic microorganisms, good laboratory practices, risk assessments, biosafety, and biosecurity capacity is becoming vital. In this study, the Food and Agriculture Organization Laboratory Mapping Tool-Safety Module was applied to demonstrate its practical implementation in the assessment of biosafety and biosecurity statuses of veterinary laboratories in Nigeria.

Methods

The Laboratory Mapping Tool-Safety Module, a standardized questionnaire, systematically and semiquantitatively gathered data on 98 subcategories covering 4 areas of biosafety and biosecurity capabilities: administrative, operational, engineering, and personal protective equipment.

Results

Overall, the various areas and categories covered by the Laboratory Mapping Tool-Safety Module were weak across the board, with a mean performance of 19.5% (95% confidence interval, 14.0%-25.1%; range, 0.8%-29.6%). The weakest functionality was in emergency preparedness (0.8%; ie, emergency responses and exercises such as fire drills, spill cleanup, and biological spill kit availability). Also, many laboratories were deficient in metrology procedures, biosafety cabinets, chemical hazard containment, regular maintenance and external calibration procedures for laboratory equipment, and personnel health and safety. However, a few functionalities within individual laboratories scored above average (50%), for example, a university microbiology laboratory animal facility (100%). Interlaboratory comparison indicated that biosafety and biosecurity performance was similar across laboratories (P = .07) and did not vary by location (P = .37).

Conclusions

Significant biosafety and biosecurity improvements are needed to guarantee the health and safety of workers and the global community, efficient responses to infectious disease containment, and compliance with the Global Health Security Agenda.

Knowledge, Attitudes, and Perceptions Associated With Antimicrobial Stewardship Among Veterinary Students: A Multi-Country Survey From Nigeria, South Africa, and Sudan

In African countries, antimicrobial resistance (AMR) issue remains pertinent. Despite this, little efforts have been made to assess the future veterinary prescribers on their knowledge, attitudes and practices (KAP) related to antimicrobial usage. This multi-country survey attempts to explore the KAP of future veterinarians on stewardship of antimicrobial and identify knowledge gaps. Eight veterinary schools participated from Nigeria, Sudan and South Africa. Data regarding perceptions and knowledge were analyzed using Chi-square χ² test, Spearman's (Rho) Rank order correlation and factor analysis using principal component factoring extraction method. Fifty-two percent of the study participants were final year veterinary students, respectively, and majority (77.2%) had no previous knowledge of biomedical sciences. Majority age were 22-27 years (24.7 ± 2.8) 79% and multiple career fields post-graduation were preferred. Overall, poor perceptions and knowledge of antimicrobial stewardship were observed with variations among countries and only 36.3% (n = 123) of the students were confident in their ability to choose the ideal antimicrobial agents for a specific patient/group of animals. The majority of the final year students were confident of their knowledge regarding AMR (68%), making of Gram staining (69.2%) and in choosing the most ideal route for administering a specific antimicrobial (74.7%). The final year students had significantly (p < 0.05) higher confidence level for knowledge compared with the pre-final year students. Tetracyclines, penicillins, and sulphonamides represent the three most abused veterinary antimicrobials with similar ranking across countries. South African (69.7 ± 20.5) and Sudanese (68.1 ± 15.4) had significantly (p < 0.0001) higher mean scores compared to the Nigerian students (44.3 ± 6.8) in the student's ability to correctly match some specific antimicrobials against their classes but Nigerian students performed better in ranking antimicrobials. This survey revealed poor to average knowledge of antimicrobial stewardship among veterinary students with significant knowledge gaps across the countries. It is recommended that the relevant regulatory and standardization authorities should make concerted efforts and interventions to regularly review curricula to ensure the delivery of targeted formative and normative training, and improved lectures on antimicrobial usage and stewardship in order to improve the awareness and behaviors of future prescribers. The identified knowledge gaps of veterinary medical students on antimicrobial stewardship must be bridge to safeguard the future.

Antimicrobial usage in pig production: Effects on Escherichia coli virulence profiles and antimicrobial resistance

Antimicrobials (AM) are used for growth promotion and therapy in pig production. Its misuse has led to the development of resistant organisms. We evaluated Escherichia coli virulence genes, and compared phenotypic-genotypic antimicrobial resistance (AMR) patterns of faecal E. coli from pigs receiving routine farm treatment without antimicrobial agents against pigs treated routinely with AM over 70 days. Recovered E. coli were tested for AMR using disk diffusion and polymerase chain reaction. Virulence genes were detected in 24.8% of isolates from antimicrobial group and 43.5% from non-antimicrobial group (p = 0.002). The proportion of virulence genes heat-stable enterotoxins a b (STa, STb), enteroaggregative heat stable enterotoxin 1 [EAST1] and Shiga toxin type 2e [Stx2e]) were 18.1%, 0.0%, 78.7% and 3.0% for antimicrobial group and 14.8%, 8.5%, 85.1% and 12.7% for non-antimicrobial groups, respectively. Resistance to oxytetracycline was most common (p = 0.03) in samples collected between days 10 and 21. Resistance shifted to amoxicillin on days 56-70, and trimethoprim resistance was observed throughout. Seventeen phenotypic AMR combinations were observed and eight were multidrug resistant. At least one tetracycline resistance gene was found in 63.9% of the isolates. tet (A) (23.3%) was most common in the antimicrobial group, whereas tet (B) (43.5%) was prevalent in the non-antimicrobial group. Usage or non-usage of antimicrobial agents in growing pigs does not preclude virulence genes development and other complex factors may be involved as previously described. Heavily used AM correspond to the degree of resistance and tetracycline resistance genes were detected during the growth phase.

Implication of the knowledge and perceptions of veterinary students of antimicrobial resistance for future prescription of antimicrobials in animal health, South Africa

Understanding the knowledge and perceptions of veterinary students of antimicrobial resistance (AMR) as potential future prescribers of antimicrobials may serve as an opportunity to improve stewardship of AMR. Pre-final (n = 42) and final (n = 29) year veterinary students of the University of Pretoria completed questionnaires to determine their knowledge and perceptions of AMR. Of the 71 respondents, mixed practice (48%) and small animal practice (45%) were the most preferred career choices post-graduation, with the field of gross pathology being the least preferred. Over 80% of the respondents believed that veterinary practitioners' misuse of antimicrobials contributes to AMR and a higher percentage (98.6%) believed that farmers' misuse of antimicrobials encourages the development of AMR, in particular, in food animals (60.6%) compared to companion animals (50.7%). Agreement in the ranking of abuse of antimicrobials between pre-final and final year students was fair (36.4%; kappa 0.3), and the most abused antimicrobials in descending order listed by the students were tetracyclines, penicillins, sulphonamides and aminoglycosides. There was wide disparity between training and potential field application, as well as variations in the correct matching of antimicrobials to their respective antibiotic classes. Responses to the clinical application of antimicrobials also varied widely. Despite the apparent teaching of AMR to veterinary students, gaps may exist in the translation of theoretical concepts to clinical applications, hence the need for focused and targeted antimicrobial prescription and stewardship training to bridge these potential identified gaps.