Antimicrobial drug resistance of enteric bacteria from broilers fed antimicrobial growth enhancers and exposed poultry abattoir workers

The usage of antimicrobials either as performance enhancers or for prophylactic and therapeutic purposes in food animals, such as chickens, increases the prevalence of antimicrobial drug resistance among enteric bacteria of these animals. This may be transferred to people working with such animals, e.g. abattoir workers, or the products arising from these animals. In this study antimicrobial drug resistance was investigated for selected enteric bacteria from broilers raised on feed supplemented with antimicrobial growth enhancers, and the people who carry out evisceration, washing and packing of intestines in a high throughput poultry abattoir in Gauteng, South Africa. Poultry farms (n=6) were purposively selected on the basis of allowing for sampling of farms from more than one grow out cycle. Broiler carcases (n=100) were randomly selected per farm five minutes after slaughter and sampled by incising caecae from the rest of the gastro-intestinal tract (GIT). The ends of each caecae were tied off to prevent contamination and to enhance the culturing of anaerobic bacteria. In the laboratory, caecal contents were selectively cultured for Clostridium perfringens, Escherichia coli, Enterococcus faecium, E. faecalis, and vancomycin-resistant enterococci (VRE). Salmonella enterica was isolated using pre-enrichment followed by selective culture. The minimum inhibitory concentration (MIC) micro broth dilution test as prescribed by the Clinical and Laboratory Standards Institute USA (CLSI), previously known as National Committee of Clinical Laboratories (NCCL), was used to determine the susceptibility of the isolates to the following antimicrobials: vancomycin, virginiamycin, doxycycline, trimethoprim, sulphamethoxazole, ampicillin, bacitracin, enrofloxacin, erythromycin, fosfomycin, ceftriaxone and nalidixic acid. The same was done on the faeces of 29 abattoir workers exposed to potentially resistant micro-organisms from broilers and 28 persons used as controls, who had not been equally exposed to potentially resistant micro-organisms from broilers. Both of the human populations had not been treated with antimicrobials within three months prior to sampling. Statistical analysis was done by Fisher’s exact test. No salmonellae and VRE on VRE selective agar (Oxoid UK) were cultured. Two Clostridium perfringens, 168 E. coli, 20 E. faecalis and 96 E. faecium isolates from the broiler caecae were cultured. Fifty four (28 and 26) E. coli, 24 (21 and 3) E. faecalis and 12 (2 and 10) E. faeciumfrom humans were cultured. The figures in brackets represent the abattoir workers and human controls respectively. The majority of E. coli isolates from broilers had MIC’s above the cut off point for the antimicrobials tested. Low resistance was observed among broiler enterococci isolates to vancomycin, virginiamycin, trimethoprim and ampicillin. A comparison of the median MIC’s of isolates from abattoir workers (packers) and the control group revealed significant differences in the median MIC’s for the following antimicrobials; E. faecalis: enrofloxacin (p=0.019). E. faecium, trimethoprim (p=0.01), enrofloxacin (p=0.029) and erythromycin (p=0.03). E. coli: trimethoprim (p=0.012) and ampicillin (p=0.036). Use of antimicrobials as feed additives causes resistance among enteric bacteria from broilers. Significant differences between median MIC’s of abattoir workers (packers) and the control group were observed for therapeutics and not growth enhancers. There was a tendency for isolates from abattoir workers to have a higher median MIC and a higher number of resistant isolates as compared to the control group. In spite of the fact that there was a high level of resistance in the enteric commensal bacteria of broiler caecae, an association could not be shown with that of the human enteric bacteria. It could not be concluded that a significant AMR transfer to poultry abattoir workers existed. This notwithstanding, both the control and experimental group, carried levels of resistance among their enteric bacteria that could be described as being high.Dissertation (MSc (Veterinary Science))--University of Pretoria, 2007.Paraclinical Sciencesunrestricte

Geographic distribution of Staphylococcus spp. infections and antimicrobial resistance among dogs from Gauteng Province presented at a veterinary teaching hospital in South Africa.

The objective of this study was to investigate spatial patterns of staphylococcal infections and resistance patterns of clinical isolates from dogs from Gauteng province in South Africa. Data from records of 1,497 dog clinical samples submitted to a veterinary teaching hospital between 2007 and 2012 were used in the study. Spatial empirical Bayesian smoothed risk maps were used to investigate spatial patterns of staphylococcal infections, antimicrobial resistance (AMR), and multidrug resistance (MDR). Moran’s I and spatial scan statistics were used to investigate spatial clusters at municipal and town spatial scales. Significant clusters of staphylococcal infections were identified at both the municipal (Relative Risk [RR]=1.71, p=0.003) and town (RR=1.65, p=0.039) scales. However, significant clusters of AMR (p=0.003) and MDR (p=0.007) were observed only at the town scale. Future larger studies will need to investigate local determinants of geographical distribution of the clusters so as to guide targeted control efforts

An Exploratory Descriptive Study of Antimicrobial Resistance Patterns of Staphylococcus Spp. Isolated from Horses Presented at a Veterinary Teaching Hospital

Background Antimicrobial resistant Staphylococcus are becoming increasingly important in horses because of the zoonotic nature of the pathogens and the associated risks to caregivers and owners. Knowledge of the burden and their antimicrobial resistance patterns are important to inform control strategies. This study is an exploratory descriptive investigation of the burden and antimicrobial drug resistance patterns of Staphylococcus isolates from horses presented at a veterinary teaching hospital in South Africa. Methods Retrospective laboratory clinical records of 1027 horses presented at the University of Pretoria veterinary teaching hospital between 2007 and 2012 were included in the study. Crude and factor-specific percentages of Staphylococcus positive samples, antimicrobial resistant (AMR) and multidrug resistant (MDR) isolates were computed and compared across Staphylococcus spp., geographic locations, seasons, years, breed and sex using Chi-square and Fisher’s exact tests. Results Of the 1027 processed clinical samples, 12.0% were Staphylococcus positive. The majority of the isolates were S. aureus (41.5%) followed by S. pseudintermedius(14.6%). Fifty-two percent of the Staphylococcus positive isolates were AMR while 28.5% were MDR. Significant (p \u3c 0.05) differences in the percentage of samples with isolates that were AMR or MDR was observed across seasons, horse breeds and Staphylococcus spp. Summer season had the highest (64.3%) and autumn the lowest (29.6%) percentages of AMR isolates. Highest percentage of AMR samples were observed among the Boerperds (85.7%) followed by the American saddler (75%) and the European warm blood (73.9%). Significantly (p \u3c 0.001) more S. aureus isolates (72.5%) were AMR than S. pseudintermedius isolates (38.9%). Similarly, significantly (p \u3c 0.001) more S. aureus (52.9%) exhibited MDR than S. pseudintermedius (16.7%). The highest levels of AMR were towards β-lactams (84.5%) followed by trimethoprim/sulfamethoxazole (folate pathway inhibitors) (60.9%) while the lowest levels of resistance were towards amikacin (14.%). Conclusions This exploratory study provides useful information to guide future studies that will be critical for guiding treatment decisions and control efforts. There is a need to implement appropriate infection control, and judicious use of antimicrobials to arrest development of antimicrobial resistance. A better understanding of the status of the problem is a first step towards that goal

Patterns and predictors of antimicrobial resistance among Staphylococcus spp. from canine clinical cases presented at a veterinary academic hospital in South Africa

Background Antimicrobial resistance in staphylococci, often associated with treatment failure, is increasingly reported in veterinary medicine. The aim of this study was to investigate patterns and predictors of antimicrobial resistance among Staphylococcus spp. isolates from canine samples submitted to the bacteriology laboratory at the University of Pretoria academic veterinary hospital between 2007 and 2012. Retrospective data of 334 Staphylococcus isolates were used to calculate the proportion of samples resistant to 15 antimicrobial agents. The Cochran-Armitage trend test was used to investigate temporal trends and logistic regression models were used to investigate predictors of antimicrobial resistance in Staphylococcus aureus and Staphylococcus pseudintermedius. Results Results show that 98.2% (55/56) of the S. aureus isolates were resistant to at least one drug while 42.9% were multidrug resistant. Seventy-seven percent (214/278) of the S. pseudintermedius isolates were resistant to at least one drug and 25.9% (72/278) were multidrug resistant. Resistance to lincospectin was more common among S. aureus(64.3%) than S. pseudintermedius (38.9%). Similarly, resistance to clindamycin was higher in S. aureus (51.8%) than S. pseudintermedius (31.7%) isolates. There was a significant (p = 0.005) increase in S. aureus resistance to enrofloxacin over the study period. Similarly, S. pseudintermedius exhibited significant increasing temporal trend in resistance to trimethoprim-sulphamethoxazole (p = 0.004), clindamycin (p = 0.022) and orbifloxacin (p = 0.042). However, there was a significant decreasing temporal trend in the proportion of isolates resistant to doxycycline (p = 0.041), tylosin (p = 0.008), kanamycin (p = 0.017) and amoxicillin/clavulanic acid (p = 0.032). Conclusions High levels of multidrug resistance and the increasing levels of resistance to sulphonamides, lincosamides and fluoroquinolones among Staphylococcus spp. isolates in this study are concerning. Future studies will need to investigate local drivers of antimicrobial resistance to better guide control efforts to address the problem

Antimicrobial resistance patterns of Staphylococcus species isolated from cats presented at a veterinary academic hospital in South Africa

Background Antimicrobial resistance is becoming increasingly important in both human and veterinary medicine. This study investigated the proportion of antimicrobial resistant samples and resistance patterns of Staphylococcus isolates from cats presented at a veterinary teaching hospital in South Africa. Records of 216 samples from cats that were submitted to the bacteriology laboratory of the University of Pretoria academic veterinary hospital between 2007 and 2012 were evaluated. Isolates were subjected to antimicrobial susceptibility testing against a panel of 15 drugs using the disc diffusion method. Chi square and Fisher’s exact tests were used to assess simple associations between antimicrobial resistance and age group, sex, breed and specimen type. Additionally, associations between Staphylococcus infection and age group, breed, sex and specimen type were assessed using logistic regression. Results Staphylococcus spp. isolates were identified in 17.6% (38/216) of the samples submitted and 4.6% (10/216) of these were unspeciated. The majority (61.1%,11/18) of the isolates were from skin samples, followed by otitis media (34.5%, 10/29). Coagulase Positive Staphylococcus (CoPS) comprised 11.1% (24/216) of the samples of which 7.9% (17/216) were S. intermedius group and 3.2% (7/216) were S. aureus. Among the Coagulase Negative Staphylococcus (CoNS) (1.9%, 4/216), S. felis and S. simulans each constituted 0.9% (2/216). There was a significant association between Staphylococcus spp. infection and specimen type with odds of infection being higher for ear canal and skin compared to urine specimens. There were higher proportions of samples resistant to clindamycin 34.2% (13/25), ampicillin 32.4% (2/26), lincospectin 31.6% (12/26) and penicillin-G 29.0% (11/27). Sixty three percent (24/38) of Staphylococcus spp. were resistant to one antimicrobial agent and 15.8% were multidrug resistant (MDR). MDR was more common among S. aureus 28.6% (2/7) than S. intermedius group isolates 11.8% (2/17). One S. intermedius group isolate was resistant to all β-lactam antimicrobial agents tested. Conclusion S. intermedius group was the most common cause of skin infections and antimicrobial resistance was not wide spread among cats presented at the veterinary academic hospital in South Africa. However, the presence of MDR-Staphylococcus spp. and isolates resistant to all β-lactams is of both public health and animal health concern

Disparities in Beef Tapeworm Identification Rates in the Abattoirs of Gauteng Province, South Africa: A Descriptive Epidemiologic Study

Background Bovine Taenia saginata cysticercus infections (also called bovine cysticercosis or beef measles) is usually diagnosed in cattle only during post-mortem meat inspection. The aim of this study was to investigate the identification rates of these infections in and to identify predictors/determinants of variations in the identification rates in abattoirs in Gauteng province, South Africa. Methods Retrospective data for over 1.4 million cattle carcasses inspected in 26 abattoirs between January 2010 and December 2013 were used for the study. The identification rates (proportion of bovine Taenia saginata cysticercus positive carcasses) were computed and generalized estimating equations used to identify predictors/determinants of identification rates. Results The overall identification rate was 0.70% (95% CI: 0.45, 0.95). Significantly (p\u3c 0.05) lower rates were reported during summer (0.55%) than other seasons. Some geographic areas reported significantly (p\u3c0.05) higher rates than others. The identification rates in high throughput abattoirs was significantly (p\u3c0.05) higher (RR: 9.4; 95% CI: 4.7–19.1) than in low throughput abattoirs. Similarly, the identification rates among animals from feedlots were significantly (p\u3c0.05) higher (RR: 1.6; 95% CI: 1.7–3.5) than those from non-feedlot sources. No significant (p\u3e0.05) association was identified between identification rates and either the number of meat inspectors per abattoir or the provider of inspection services. Conclusion Although no significant association was found between identification rates and provider of inspection services, follow-up studies will need to be done to specifically investigate the potential conflict of interest arising from the fact that abattoir owners hire meat inspection services directly. Capture of abattoir surveillance data needs to include farm address and for each case to be reported separately. Finally, information on the type of identified cysts (alive or calcified) need to be collected to help better estimate risk to consumers. This study provides useful baseline data to guide future studies, surveillance and control efforts

Antimicrobial resistance among Escherichia coli isolates from dogs presented with urinary tract infections at a veterinary teaching hospital in South Africa

Abstract Background This study investigated the burden and predictors of canine E. coli urinary tract infections (UTI) and antimicrobial resistance among dogs presented at a veterinary teaching hospital in South Africa, 2007–2012. Methods The Cochran-Armitage trend test was used to investigate temporal trends while logistic regression models were used to investigate predictors (age, sex, breed, year) of E. coli infections and antimicrobial resistance (AMR). Results A total of 22.3% (168/755) of the urinary specimens tested positive for E. coli. A significant (p = 0.0004) decreasing temporal trend in the percentage of E. coli positive isolates was observed over the study period. There were high levels of AMR to penicillin-G (99%), clindamycin (100%), tylosine (95%), cephalothin (84%) but relatively low levels of resistance to enrofloxacin (16%), orbifloxacin (21%). Almost all (98%, 164/167) the isolates exhibited multidrug resistance (MDR), while only 11% (19/167) and 2% (4/167) exhibited extensive drug resistance (XDR) and pan-drug resistance (PDR), respectively. Conclusions Although, the risk of E. coli UTI declined during the study period, the risk of AMR increased. The high levels of AMR and MDR as well as the presence of XDR and PDR is concerning as these have the potential of affecting prognosis of UTI treatments

Antimicrobial resistance among Escherichia coli isolates from dogs presented with urinary tract infections at a veterinary teaching hospital in South Africa

Background This study investigated the burden and predictors of canine E. coli urinary tract infections (UTI) and antimicrobial resistance among dogs presented at a veterinary teaching hospital in South Africa, 2007–2012. Methods The Cochran-Armitage trend test was used to investigate temporal trends while logistic regression models were used to investigate predictors (age, sex, breed, year) of E. coli infections and antimicrobial resistance (AMR). Results A total of 22.3% (168/755) of the urinary specimens tested positive for E. coli. A significant (p = 0.0004) decreasing temporal trend in the percentage of E. coli positive isolates was observed over the study period. There were high levels of AMR to penicillin-G (99%), clindamycin (100%), tylosine (95%), cephalothin (84%) but relatively low levels of resistance to enrofloxacin (16%), orbifloxacin (21%). Almost all (98%, 164/167) the isolates exhibited multidrug resistance (MDR), while only 11% (19/167) and 2% (4/167) exhibited extensive drug resistance (XDR) and pan-drug resistance (PDR), respectively. Conclusions Although, the risk of E. coli UTI declined during the study period, the risk of AMR increased. The high levels of AMR and MDR as well as the presence of XDR and PDR is concerning as these have the potential of affecting prognosis of UTI treatments

Geographic distribution of staphylococcus spp. infections and antimicrobial resistance among dogs from Gauteng Province presented at a veterinary teaching hospital in South Africa

The objective of this study was to investigate spatial patterns of staphylococcal infections and resistance patterns of clinical isolates among dogs from Gauteng province in South Africa. Data from records of 1497 dog clinical samples submitted to a veterinary teaching hospital between 2007 and 2012 were used in the study. Spatial empirical Bayesian smoothed risk maps were used to investigate spatial patterns of staphylococcal infections, antimicrobial resistance (AMR), and multidrug resistance (MDR). Moran's I and spatial scan statistics were used to investigate spatial clusters at municipal and town spatial scales. Significant clusters of staphylococcal infections were identified at both the municipal (Relative Risk [RR] = 1.71, p = 0.003) and town (RR = 1.65, p = 0.039) scales. However, significant clusters of AMR (p = 0.003) and MDR (p = 0.007) were observed only at the town scale. Future larger studies will need to investigate local determinants of geographical distribution of the clusters so as to guide targeted control efforts.http://www.elsevier.com/locate/sstehj2020Paraclinical Science

Spatial patterns of anthrax outbreaks and cases among livestock in Lesotho, 2005–2016

BACKGROUND: Although anthrax occurs globally, the burden of the disease remains particularly high in Africa. Furthermore, the disease anthrax has significant public health and economic implications. However, sufficient attention has not been given to the geographic distribution of anthrax outbreaks and cases in Lesotho. Therefore, this study investigates the spatial patterns of anthrax outbreaks and cases among livestock in Lesotho from 2005 to 2016. METHODS: A cross-sectional study design was adopted to realise the objectives of this study using retrospective data of anthrax outbreaks and cases recorded by the Department of Livestock Services (DLS) between 2005 and 2016. Anthrax outbreaks were geo-coded at village level and aggregated at district level. Proportions and 95% CI of anthrax outbreaks and cases by village and district were calculated. Cartographic maps displaying the distribution of anthrax outbreaks and cases at village and district level were constructed. RESULTS: A total of 38 outbreaks were reported over the study period, and they were clustered in the Lowlands districts of Lesotho. Most outbreaks (52.6%, 20/38) in livestock were reported in the Maseru district. The Leribe district reported the lowest proportions of outbreaks (5.3%, 2/38) and cases (0.6%, 3/526). At the village level, 18% (7/38) of outbreaks were in Maseru Urban, followed by Ratau (16%, 6/38) and Mofoka (13%, 5/38). The Maseru district reported the highest (1.3%, 369/29,070) proportion of cases followed by Mafeteng (0.9%, 73/8530). The village with the most cases was Kolo (10.5%, 21/200), followed by Thaba-Chitja (7.7%, 33/430). CONCLUSION: Anthrax outbreaks and cases exclusively occur in the Lowlands districts of Lesotho, with villages such as Mahobong, Pitseng, Kolo, and Thaba-Chitja having a higher risk of anthrax disease. Findings of the present study have serious public health implications in light of the fact that between 2003 and 2008 Lesotho’s main abattoir was closed; hence, most of the meat in Lesotho was imported and/or sourced from the informal slaughter facilities. Much larger studies are needed to further investigate factors contributing to spatial disparities in anthrax outbreaks and cases observed in this study. Findings of the present study can be used to guide the formulation of a policy on prevention and control of anthrax in Lesotho.http://www.mdpi.com/journal/ijerphpm2021Paraclinical Science