Drivers of antimicrobial resistance in layer poultry farming: Evidence from high prevalence of multidrug-resistant Escherichia coli and enterococci in Zambia

Prevalence and factors associated with multidrug resistant Escherichia coli carriage on chicken farms in west Nile region in Uganda: A cross-sectional survey

Infections with multi-drug-resistant (MDR) pathogens in food-animals threaten public health and food security. However, the epidemiology and factors associated with MDR Escherichia coli (MDR E. coli) on Ugandan farms are not well known. This study investigated the prevalence, resistance patterns and factors associated with MDR E. coli carriage on chicken farms. Escherichia coli was isolated from each of the 158 chicken farms sampled. The disc diffusion method for susceptibility testing was performed. Clinical breakpoints were interpreted according to Clinical and Laboratory Standards Institute guidelines. MDR was defined as resistance to three or more classes of antibiotics. MDR E. coli prevalence on chicken farms was 62.7% (95% CI: 55.0-70.3). High resistance was observed against ampicillin 79.8% (95% CI: 72.7-85.4), tetracycline 72.8% (95% CI: 65.2-79.2), cotrimoxazole 55.7% (95% CI: 47.8-63.3), and ciprofloxacin 38% (95% CI: 30.7-45.9). Male farm managers (Adjusted prevalence ratio [APR] = 0.72, CI: 0.55-0.93), attainence of at least secondary education (APR = 0.64, CI: 0.46-0.88) and administration of recommended antibiotic doses (APR = 0.76, CI: 0.59-0.96) posed a lower risk of MDR E. coli carriage while farms without footbaths posed a heighten risk (APR = 1.48, CI: 1.16-1.88). MDR E. coli carriage was highly prevalent on chicken farms in Uganda. This study underscores the urgent need for antimicrobial stewardship and improved infection prevention strategies on chicken farms.

Community pharmacists' knowledge and practices towards antimicrobial stewardship: findings and implications

BACKGROUND

Antimicrobial stewardship (AMS) programmes have been implemented around the world to optimally manage antimicrobial use to attenuate antimicrobial resistance (AMR). This study assessed the knowledge and practices of community pharmacists towards AMS strategies in the Lusaka District, Zambia.

METHODS

This cross-sectional study was conducted among 194 community pharmacists in the Lusaka district using a structured questionnaire from August 2022 to September 2022. Data analysis was done using Statistical Package for Social Science (SPSS) version 22.0.

RESULTS

Of the 194 participants, 86% of the community pharmacists had good knowledge of AMS. The present study found that 83.5% were aware of AMS strategies used in community pharmacy practice. Further, 83.5% of the CPs were familiar with the goals of AMS and 89.2% believed that AMS was necessary for their pharmacy practice. Furthermore, 66.7% of the participants exhibited good practice towards the AMS strategies. Finally, 61.3% frequently avoided the use of broad-spectrum antimicrobials that were not necessary.

CONCLUSIONS

According to the findings of this study, the majority of community pharmacists had good knowledge of the AMS strategies that were employed to combat AMR; nonetheless, some of them had poor practices. Therefore, there is a need for community pharmacists to have access to sufficient ongoing professional development programmes and educational activities through AMS programmes to address AMR.

Antimicrobial Use Survey and Detection of ESBL-Escherichia coli in Commercial and Medium-/Small-Scale Poultry Farms in Selected Districts of Zambia

Antimicrobial resistance (AMR) among Escherichia coli from food animals is a rising problem, and heavy antimicrobial use in poultry is a contributing factor. In Zambia, studies linking poultry-associated AMR and antibiotic use (AMU) are rare. This study aimed to investigate commercial and medium-/small-scale poultry farmers' usage of antimicrobials based on a questionnaire survey in ten districts of Zambia. In addition, the study characterized extended-spectrum β-lactamase (ESBL)-producing E. coli isolates obtained from poultry in the same districts. Data regarding knowledge and usage of antimicrobials were collected from commercial and medium-/small-scale poultry farmers using a pre-tested structured questionnaire. At the same time, cloacal samples were collected and analyzed. One hundred and fifty E. coli isolates were tested for antimicrobial susceptibility using eight antibiotic classes. The isolates were further screened for ESBL production by streaking them on cefotaxime (CTX)-supplemented MacConkey agar, then subjecting them to sequencing on a NextSeq. The questionnaire survey showed that more medium-/small-scale than commercial poultry farmers used antimicrobials (OR = 7.70, 95% CI = 2.88-20.61) but less prescriptions (OR = 0.02, 95% CI = 0.00-0.08). Susceptibility testing revealed that resistance was highest to ampicillin (128/148, 86.5%) and tetracycline (101/136, 74.3%) and that the prevalence of multidrug resistance (MDR) (28/30, 93.3%) was high. Whole-genome sequencing (WGS) of eight (8/30, 26.7%) isolates with CTX Minimum Inhibitory Concentration (MIC) ≥ 4 µg/mL revealed the presence of ESBL-encoding genes blaCTX-M-14, blaCTX-M-55, and blaTEM. WGS also detected other AMR genes for quinolones, aminoglycosides, phenicols, tetracycline, macrolides, and folate-pathway antagonists. Altogether, the questionnaire survey results showed a higher proportion of AMU and lower prescription usage among medium-/small-scale farmers. In addition, our results emphasize the circulation of ESBL-producing E. coli strains with associated MDR. It is critical to educate farmers about AMR risks and to encourage responsible usage of antimicrobials. Furthermore, there is a need to strengthen regulations limiting access to antimicrobials. Finally, there is a need to establish a one health system to guide public health response.

Community antibiotic consumption and associated factors in Lusaka district of Zambia: findings and implications for antimicrobial resistance and stewardship

Introduction

Antimicrobial resistance (AMR) is a global public health crisis. This study assessed the general public's consumption of antibiotics and associated factors in the Lusaka district of Zambia.

Methods

This cross-sectional study was conducted among 2038 participants between December 2022 and January 2023. Data were analysed using Stata 13.0. Multivariable regression techniques were used to determine the factors that influenced antibiotic consumption.

Results

Of the 2038 participants, 53.4% were female, and 51.5% had attended at least secondary school. Antibiotic use was 99.2%, of which 40.9% were appropriately used. Overall, 79.1% of antibiotics were prescribed in hospitals, while 20.9% were used from leftovers and accessed without prescriptions. This study found that the appropriate use of antibiotics was associated with being female, being aged 35 years and above, attaining secondary school or tertiary education, having a monthly expenditure of 195 USD and above, being aware that antibiotics were not the same as painkillers, and being confident that when someone was hospitalized, they would get well.

Conclusions

This study found that the appropriate use of antibiotics was low, and this is an urgent public health issue requiring community engagement in tackling AMR and adherence to treatment guidelines in healthcare facilities. Additionally, there is a need to implement and strengthen antimicrobial stewardship programmes in healthcare facilities to promote the rational use of antibiotics in Zambia. There is also a need to heighten community awareness campaigns and educational activities on the appropriate use of antibiotics.

Detection of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Enterobacteriaceae from Diseased Broiler Chickens in Lusaka District, Zambia

Poultry products in Zambia form an integral part of the human diet in many households, as they are cheap and easy to produce. The burden of poultry diseases has, however, remained a major challenge. Growing consumer demand for poultry products in Zambia has resulted in non-prudent antimicrobial use on farms, intending to prevent and treat poultry diseases for growth optimisation and maximising profits. This cross-sectional study aimed to identify the different types of bacteria causing diseases in chickens in Lusaka and to detect the extended-spectrum lactamase (ESBL)-encoding genes. We collected 215 samples from 91 diseased chickens at three post-mortem facilities and screened them for Gram-negative bacteria. Of these samples, 103 tested positive for various clinically relevant Enterobacteriaceae, including Enterobacter (43/103, 41.7%), Escherichia coli (20/103, 19.4%), Salmonella (10/103, 9.7%), and Shigella (8/103, 7.8%). Other isolated bacteria included Yersinia, Morganella, Proteus, and Klebsiella, which accounted for 21.4%. E. coli, Enterobacter, Salmonella, and Shigella were subjected to antimicrobial susceptibility testing. The results revealed that E. coli, Enterobacter, and Shigella were highly resistant to tetracycline, ampicillin, amoxicillin, and trimethoprim-sulfamethoxazole, while Salmonella showed complete susceptibility to all tested antibiotics. The observed resistance patterns correlated with antimicrobial usage estimated from sales data from a large-scale wholesale and retail company. Six (6/14, 42.9%) E. coli isolates tested positive for blaCTX-M, whilst eight (8/14, 57.1%) Enterobacter samples tested positive for blaTEM. Interestingly, four (4/6, 66.7%) of the E. coli isolates carrying blaCTX-M-positive strains were also positive for blaTEM. Sanger sequencing of the PCR products revealed that five (5/6, 83.3%) of the abovementioned isolates possessed the blaCTX-M-15 allele. The results suggest the presence of potentially pathogenic ESBL-producing Enterobacteriaceae in poultry, threatening public health.