The most widely distributed bla_CTX-M gene on a global scale is bla_CTX-M-15. The dissemination has been associated with clonal spread and different types of mobile genetic elements. This study aimed to review and describe the genetic environments of bla_CTX-M-15 gene detected from Enterobacteriaceae in published literature from Africa. A literature search for relevant articles was done through PubMed, and Google Scholars electronic databases, 43 articles from 17 African countries were included in the review based on the eligibility criteria. Insertion sequences were reported as part of the genetic environment of bla_CTX-M-15 gene in 32 studies, integrons in 13 studies, and plasmids in 23 studies. In this review, five insertion sequences including ISEcp1, IS26, orf447, IS903, and IS3 have been detected associated with the genetic environment of bla_CTX-M-15 in Africa. Seven different genetic patterns were seen in bla_CTX-M-15 genetic environment. Insertion sequence ISEcp1 was commonly located upstream of the end of the bla_CTX-M-15 gene while insertion sequence orf477 was located downstream. In some studies, ISEcp1 was truncated upstream of bla_CTX-M-15 by insertion sequences IS26 and IS3. Class 1 integron (Intl1) was most reported to be associated with bla_CTX-M-15 (13 studies), with Intl1/dfrA17–aadA5 being the most common gene cassette array. IncFIA-FIB-FII multi-replicons and IncHI2 replicon types were the most common plasmid replicon types that horizontally transfer bla_CTX-M-15 gene. Aminoglycoside modifying enzymes, and plasmid-mediated quinolone resistance genes were commonly collocated with bla_CTX-M-15 gene on plasmids. This review revealed the predominant role of ISEcp1, Intl1and IncF plasmid in the mobilization and continental dissemination of the bla_CTX-M-15 gene in Africa.

This review was carried out to identify different beta-lactamase resistance genes reported in published literature from Nigeria and to determine the proportion estimates of the important beta-lactamase resistance genes in Nigeria. Sixty-three (63) articles were included in this review based on the eligibility criteria. All the beta-lactamases reported were detected from the Gram-negative bacteria, most especially from Enterobacteriaceae (n=53). Thirty-six different beta-lactamase genes have been reported from Nigeria. These genes belong to the narrow-spectrum, AmpC, extended-spectrum, and carbapenemase beta-lactamase resistance genes. Eight (8) genes (bla_DHA, bla_CTXM-1, bla_CTXM-14, bla_GES-1, bla_VEB-1, bla_OXA-1, bla_OXA-2, and bla_TEM-1) were shared between animals and humans, 5 genes (bla_SHV-1, bla_SHV-2, bla_SHV-11, bla_SHV-12, and bla_NDM-1) were common to both humans and environment while none of the genes was unique to both animals and environment. Four genes including bla_CMY, bla_TEM-1, bla_AmpC, and internationally pandemic bla_CTXM-15 gene were unique to animals, humans, and the environment. No carbapenemase gene was reported from animals yet. The pooled proportion estimate of ESBL genes in Nigeria was 31% (95% CI: 26-36%, P<0.0001), while the estimate of bla_CTXM-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). This study has provided information on the beta-lactamases 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.

Backyard chickens are the most popular poultry in Bangladesh due to their production potential, and income generation. However, this farming can be a factor in zoonotic disease transmission. This study aimed to assess the knowledge, attitudes, and practices (KAP) related to biosecurity and management among backyard chicken households in Bangladesh. A cross-sectional survey was conducted among 295 households in six sub-districts of different six divisions of Bangladesh. The study used a convenient sampling technique to choose the divisions, then the districts and sub-districts. A well-structured pre-tested questionnaire was used to interview randomly selected households. In this study, most of the respondents relied on agriculture crop production (n=128) as their primary source of income, relied on scavenging for their birds’ feeding (34%), or fed their chickens whole or broken rice (32%), used tube well water (58%), used ash (38%) or sand (28%) as litter material. A significant proportion of households (40%) did not use any nest box at all. Results also showed that the most reported poultry diseases among backyard poultry farmers were Newcastle disease (49%), followed by coccidiosis (30%), fowl cholera (12%), and fowl pox (9%). In the multivariate logistic regression model, knowledge of biosecurity was associated with the household type (OR=1.4, p=0.04), knowledge of vaccination (OR=3.7, p=0.02), don’t know category (OR=4.2, p=<0.001), provision of the nest box (OR=9.5, p<0.001), training (OR=0.1, p=0.04), and air pollution (OR=0.1; p=0.04). The study found a huge knowledge gap on management and biosecurity practices present among backyard chicken farmers, which can negatively impact public health for instance in the outbreak of zoonotic diseases. Increasing farmers' biosecurity awareness through education and outreach activities could minimize the risk of disease transmission and improve both public and poultry health.