Assessing the mechanisms of multi-drug resistant non-typhoidal Salmonella (NTS) serovars isolated from layer chicken farms in Nigeria.

BACKGROUND: In Nigeria, there have been reports of widespread multiple antimicrobial resistance (AMR) amongst Salmonella isolated from poultry. To mitigate the impact of mortality associated with Salmonella on their farms, farmers resort to the use of antimicrobials without sound diagnostic advice. We conducted this study to describe the AMR patterns, mechanisms and genetic similarities within some Salmonella serovars isolated from different layer farms. METHOD: We determine the AMR profiles of two hundred Salmonella isolates, selected based on frequency, serovar, and geographical and sample type distribution. We also assessed the mechanisms of multi-drug resistance for specific genetic determinants by using PCR protocols and gene sequence analysis. Pulsed-field gel electrophoresis (PFGE) was conducted on seven selected serovars to determine their genetic relatedness. RESULTS: Of 200 isolates, 97 (48.5%) revealed various AMR profiles, with the multiple antibiotic resistance (MAR) index ranging from 0.07-0.5. Resistance to ciprofloxacin was common in all the multi-drug resistant isolates, while all the isolates were susceptible to cefotaxime, ceftazidime, and meropenem. Genotypic characterization showed the presence of resistance genes as well as mutations in the nucleotide genes with subsequent amino acid substitutions. Fifteen isolates (43%) of S. Kentucky were indistinguishable, but were isolated from four different states in Nigeria (Ogun, n = 9; Kaduna, n = 6; Plateau, n = 3, and: Bauchi, n = 2). PFGE revealed 40 pulsotype patterns (Kentucky, n = 12; Larochelle, n = 9; Virchow, n = 5; Saintpaul, n = 4; Poona, n = 3; Isangi, n = 2, and; Nigeria, n = 2). CONCLUSION: This study recorded strictly related but diversely distributed Salmonella serovars with high AMR rates in poultry. We recommend strict regulation on antimicrobial use and regular monitoring of AMR trends among bacteria isolated from animals and humans to inform public policy.

Determination of antimicrobial use in commercial poultry farms in Plateau and Oyo States, Nigeria.

BACKGROUND: Indiscriminate use of antimicrobials for the prevention and treatment of bacterial infection in animals is a common practice in Nigeria as in other developing countries. These antimicrobials are purchased over the counter without restrictions and often administered in form of medicated feedstuffs. In Nigeria, like most developing countries, antimicrobial prescription data are not routinely collected or reported at the farm level, instead import data are used in reporting antimicrobial consumption. Farmers can be useful sources of data on the use of antimicrobial agents by class, animal species, production type and age. The objective of the study was to determine the knowledge, attitude and practices of poultry farmers on antimicrobial resistance and to generate data on antimicrobial use (AMU) in poultry farms in Plateau and Oyo states in accordance with the guidelines of the World Organization for Animal Health (WOAH). METHODS: A questionnaire used by the Food and Agriculture Organization (FAO) of the United Nations in Ghana was adopted and modified to collect data on the knowledge, attitude and practices of farmers on AMR and AMU and to collect AMU data from selected poultry farms. A focus group discussion (FGD) was conducted in Plateau state with poultry farmers and representatives from the state veterinary services, using a checklist. The aim of the FGD was to have an idea on antimicrobial use among poultry farmers and to generate additional questions that might be added to the questionnaire. Stratified random sampling technique was used to select 50 farms from Plateau and Oyo states, using the list of registered poultry farms in the two states as sampling frame. RESULTS: Ninety eight percent (98%) of farmers gave antibiotics as prophylactic treatment to day old chicks. There were 47 different products used in the two states within the study period. We observed that five classes of antibiotics (Tetracyclines, Penicillins, Aminoglycosides, Polypeptides and Fluoroquinolone) were used in the two states. A total of 351 kg of active ingredients from seven different classes, namely: tetracyclines, penicillins, aminoglycosides, polypeptide, fluoroquinolones, amphenicol and macrolides were recorded from the two states. Some products contained cocktail of antibiotics, having up to six different classes with very high concentration of active ingredients which are not in the list of registered antimicrobials reported to WOAH. CONCLUSION: The concept used for this survey proved that the approach can be applied for AMU surveillance in the animal health sector. It also provided insight on farmers' knowledge and practices with regards to the use of antimicrobials which is missing in the national import data. The need for "stronger" antibiotics was identified as one of the drivers of antibiotic resistance.

Cholera outbreak in some communities in North-East Nigeria, 2019: an unmatched case-control study.

BACKGROUND: Cholera, a diarrheal disease caused by the bacterium Vibrio cholerae, transmitted through fecal contamination of water or food remains an ever-present risk in many countries, especially where water supply, sanitation, food safety, and hygiene are inadequate. A cholera outbreak was reported in Bauchi State, North-eastern Nigeria. We investigated the outbreak to determine the extent and assess risk factors associated with the outbreak. METHODS: We conducted a descriptive analysis of suspected cholera cases to determine the fatality rate (CFR), attack rate (AR), and trends/patterns of the outbreak. We also conducted a 1:2 unmatched case-control study to assess risk factors amongst 110 confirmed cases and 220 uninfected individuals (controls). We defined a suspected case as any person > 5 years with acute watery diarrhea with/without vomiting; a confirmed case as any suspected case in which there was laboratory isolation of Vibrio cholerae O1 or O139 from the stool while control was any uninfected individual with close contact (same household) with a confirmed case. Children under 5 were not included in the case definition however, samples from this age group were collected where such symptoms had occurred and line-listed separately. Data were collected with an interviewer-administered questionnaire and analyzed using Epi-info and Microsoft excel for frequencies, proportions, bivariate and multivariate analysis at a 95% confidence interval. RESULTS: A total of 9725 cases were line-listed with a CFR of 0.3% in the state. Dass LGA had the highest CFR (14.3%) while Bauchi LGA recorded the highest AR of 1,830 cases per 100,000 persons. Factors significantly associated with cholera infection were attending social gatherings (aOR = 2.04, 95% CI = 1.16-3.59) and drinking unsafe water (aOR = 1.74, 95% CI = 1.07-2.83). CONCLUSION: Attending social gatherings and drinking unsafe water were risk factors for cholera infection. Public health actions included chlorination of wells and distribution of water guard (1% chlorine solution) bottles to households and public education on cholera prevention. We recommend the provision of safe drinking water by the government as well as improved sanitary and hygienic conditions for citizens of the state.

Salmonella enterica Newserovar Abeokuta Genome Sequence, Strain OG19FER4 Isolated from Poultry Feed in Nigeria.

This report announces the genome of a newly confirmed Salmonella serovar (Salmonella enterica serovar Abeokuta) that was isolated from a poultry feed sample collected on a farm in Abeokuta, capital of Ogun State in Nigeria. Salmonella Abeokuta has not been identified outside Nigeria, nor does it appear to be a cause for concern for animal and human health.

Perceptions and practices of farmers of indigenous poultry towards Salmonella infections in North-Central Nigeria.

Background: Salmonella infections continue to be of global concern to poultry health, productivity, and public health. About 44% of the poultry in Nigeria are indigenous and kept in close interaction with farmers who are mostly rural dwellers and have limited access to veterinary and extension services. Aim: The perceptions and practices of farmers of indigenous poultry toward Salmonella infections were assessed to obtain and document baseline data that can be used to create awareness among farmers about these infections and their attendant public health implications. Methods: A cross-sectional approach using a multistage sampling method was used in this survey. A total of 419 farmers keeping indigenous poultry were interviewed using a pre-tested electronic questionnaire in three randomly selected states within North-Central Nigeria. Data were analyzed using descriptive and regression analysis. Results: Out of the 419 respondents, 138 (32.9%), 141 (33.7%), and 140 (33.4%) were from Benue, Kwara, and Plateau States, respectively. Of the 419, 55.4% were females, 40.8% were above 40 years, and 35.8% have over 10 years of farming experience. The majority of the poultry are not housed (58.5%) and farmers predominantly rear chickens (51.8%). Also, 49.9% of the birds were 1-6 months with 41.5% of the flock sizes being 11-20. Respondents had a poor level of perception toward Salmonella infection as the majority did not know that Salmonella affects poultry (89.3%) and that Salmonella infections are zoonotic (94.5%). Significant (p = 0.000) associations existed between categorized perception score and age, educational status, family size, and farming experience of farmers. There were significant (p = 0.000) associations of categorized practice scores with gender, age, education status, family size, and farming experience of farmers. Conclusion: This study has revealed the poor perception of farmers on Salmonella infections and has highlighted their practices. There is a need to raise awareness about these infections to improve indigenous poultry health and productivity as well as public health.

Questionnaire Survey on Knowledge, Attitude and Practices on COVID 19 Outbreak Among Veterinarians in Nigeria.

Coronavirus Disease 2019 (COVID-19), a viral pneumonia-like disease caused by novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) started in Wuhan, Hubei Province of China on December 31st 2019, and assumed a pandemic status; infecting about 30 million people, with a mortality in excess of 957,000 as at 20st September, 2020. This study assessed the knowledge, attitude, and practices concerning COVID-19 among veterinarians with a view to detecting variables that may hinder their effective contributions towards the management and control of COVID-19 outbreak in Nigeria.The study found that male veterinarians had significantly good knowledge (p=0.012, OR=0.157, CI=0.03-0.66) and attitude (OR=18.415, CI=1.45-5.16, P=0.011) towards COVID-19 than female counterparts. Similar results were also recorded regarding practices (OR=2.941, CI=1.03-8.36, P=0.043). Educational qualification was found to be significantly associated with attitude of veterinarians in respect of COVID-19 prevention (OR=0.473, CI=0.073-0.011, P=0.006). Thus, gender (male) was found to be independent predictors of good knowledge, attitude and practices regarding COVID-19. In addition, educational qualification was also found to be an independent predictor of attitude of veterinarians regarding COVID-19 control. Veterinarians generally had good knowledge about the epidemiology, diagnosis, treatment and prevention of COVID-19. However, despite their knowledge, the level of willingness of veterinarians to support national response activities was still poor. This study advocated for a collaborative efforts (one-health) between medics and vets in tackling future pandemics/infectious diseases like COVID-19. In addition, since most vet knows the basics of infectious diseases like COVID-19, they can be deployed for national response activities.

Investigation of potential risk factors associated with Salmonella presence in commercial laying hen farms in Nigeria.

BACKGROUND: In 2012/13, the Federal government of Nigeria approved the surveillance of salmonellae in commercial poultry farms with the aim of generating baseline data for the development of a control programme. That baseline provided an opportunity to investigate potential risk factors in commercial layer farms. METHODS: Five hundred and twenty-three farms were evaluated for the presence of Salmonella. Each farmer was interviewed through a structured questionnaire. Univariate analysis identified 26 variables potentially associated with Salmonella presence on the farms, with different levels of significance. To simultaneously evaluate the effect of these variables, a multivariable logistic regression model was implemented. RESULTS: Farmers that are member of the Poultry Association of Nigeria (PAN) emerged as a risk factor, as well as being farmer as exclusive occupation. The risk of Salmonella increased in farms with a combined housing system as compared to farms with a single housing system. Moreover, in terms of farm management the use of plastic egg crates had a higher risk of Salmonella presence compared to paper crates. Higher risk of contamination was also identified in farms having regular contact with animal health workers, since this could be indicative of animal health problems requiring continuous assistance. Farms with no previous outbreak of salmonellosis were associated with an increase risk, since most of the farms in this category were newly established. With regard to feeding, the use of coccidiostats and commercial feeds were associated with the spread of Salmonella. Unexpectedly, the presence of other farms at distances further than 1 km away was associated with an increase in Salmonella presence as compared to farms which were in closer proximity. Close proximity among farms could favour the application of stricter biosecurity measures. CONCLUSIONS: The results of the survey can be considered a baseline for implementing effective measures aimed at reducing the Salmonella prevalence in Nigerian laying hen farms.

Salmonella serovars and their distribution in Nigerian commercial chicken layer farms.

Commercial poultry farms (n° 523), located in all the six regions of Nigeria were sampled with a view to generate baseline information about the distribution of Salmonella serovars in this country. Five different matrices (litter, dust, faeces, feed and water) were collected from each visited farm. Salmonella was isolated from at least one of the five matrices in 228 farms, with a farm prevalence of 43.6% (CI95[39.7-48.3%]). Altogether, 370 of 2615 samples collected (14.1%, CI95[12.8; 15.5%]) contained Salmonella. Considering the number of positive farms and the number of positive samples, it was evident that for the majority of the sampled farms, few samples were positive for Salmonella. With regard to the matrices, there was no difference in Salmonella prevalence among the five matrices considered. Of the 370 isolates serotyped, eighty-two different serotypes were identified and Salmonella Kentucky was identified as having the highest isolation rate in all the matrices sampled (16.2%), followed by S. Poona and S. Elisabethville. S. Kentucky was distributed across the country, whereas the other less frequent serovars had a more circumscribed diffusion. This is one of few comprehensive studies on the occurrence and distribution of Salmonella in commercial chicken layer farms from all the six regions of Nigeria. The relatively high prevalence rate documented in this study may be attributed to the generally poor infrastructure and low biosecurity measures in controlling stray animals, rodents and humans. Data collected could be valuable for instituting effective intervention strategies for Salmonella control in Nigeria and also in other developing countries with a similar poultry industry structure, with the final aim of reducing Salmonella spread in animals and ultimately in humans.

Motile Salmonella serotypes causing high mortality in poultry farms in three South-Western States of Nigeria.

This study was carried out to identify the Salmonella serotypes causing high mortality in chickens in Lagos, Ogun and Oyo states, Nigeria. Chickens presented for postmortem examination during disease outbreaks that were characterised by high mortality (40 per cent to 80 per cent) in poultry farms in the study area were examined from January to December, 2013. Samples of the lungs, heart, liver, spleen, kidneys, proventriculus, intestine and caecum were collected from suspected cases of salmonellosis, for bacterial culture and identification. Salmonella isolates were confirmed using PCR and serotyped using the Kauffman-White scheme. Twenty-six day-old pullets were raised to two weeks and inoculated orally with 0.2 mL of 1×108 colony forming units of Salmonella Zega identified in the present study to determine their pathogenicity, while another 26 served as control. The Salmonella serotypes were S Zega (n=13; 35.14 per cent), Salmonella Kentucky (n=9; 24.32 per cent), Salmonella Herston (n=6; 16.22 per cent), Salmonella Nima (n=4; 10.81 per cent), Salmonella Telelkebir (n=3; 8.11 per cent), Salmonella Colindale (n=1; 2.70 per cent) and Salmonella Tshiongwe (n=1; 2.70 per cent). Clinical signs in both natural and experimental infections were acute (70 per cent) and chronic (30 per cent), and included weakness, anorexia, yellowish diarrhoea, pasted vents, somnolescence and mortality, while gross lesions showed marked pulmonary congestion and oedema, necrotic foci in the myocardium; the liver, spleen and kidneys were markedly enlarged and had subcapsular multifocal necrosis. There were catarrhal proventriculitis and enteritis, and haemorrhagic typhlitis. While most of the serotypes identified in the present study have been isolated from poultry sources from commercial farms in Nigeria, to the best of the authors' knowledge, they have not been previously reported to cause high mortality in chickens in the study area.

Response of Nigerian farmers to a questionnaire on chloramphenicol application in commercial layers.

The authors assessed the occurrence of chloramphenicol (CAP) residues in commercial eggs. Of the 105 farmers surveyed for the use of CAP, 35 (33.3%) and 70 (66.7%) responded regarding their awareness or complete lack of awareness of the legislation that stipulates the use of CAP in food animals, including poultry, respectively. Only 28 (26.7%) of respondent farmers were aware that CAP was one of the drugs that is not recommended for use in food animals. Amongst the farms surveyed in the preliminary phase of this study, 24 were randomly sampled for further investigation, of which 21 (20.0%) admitted the use of CAP in forms of human and veterinary preparations, while 15 (62.5%) admitted the use of human CAP preparation only. The presence of antimicrobial residues was confirmed using specific thin-layer chromatography (STLC) in 8 out of 144 pooled egg samples (10 eggs per sample). The only positive CAP sample was identified on a farm that adopted the use of a human CAP preparation.