Bacterial Carriage And Respective Antimicrobial Susceptibility Profiles, With Respect To Indigenous Chickens Marketed In Nairobi, Kenya; After Heavy Rains

Abstract

Indigenous chickens are mostly raised free-range, where they scavenge around, picking their food from the environment with little or no supplementation. During periods of heavy rains, the flooding water carries different materials and wastes, like bacteria, antibiotics and disinfectants among others, from one place to another. These may end up being picked by the feeding free-range chickens. If the picked bacteria are antibiotic/disinfectant resistant, the respective resistance may be transferred to other bacteria in chicken and humans who consume the chicken products. If transferred to pathogenic ones, this will complicate control of the resultant disease(s). Antimicrobial resistance is currently a worldwide problem that is attracting a lot of attention to scientists. This study was carried out to determine bacterial carriage and respective antimicrobial susceptibility profiles in slaughtered indigenous chickens after heavy rains of year 2018, in Nairobi. One hundred and twenty (120) intestine samples of indigenous chickens from three slaughter houses in Nairobi, namely: Kariokor, Burma and Kangemi were used in this study. Bacterial quantification was done using the method given by Miles and Misra (1938) while bacterial isolation and identification were done using standard bacteriological methods and tests by Markey et al., (2013). The three most isolated bacteria, Escherichia coli, Staphylococcus spp and Streptococcus spp, were further tested for antibiotic and disinfectant susceptibility using gel diffusion method. For antibiotic susceptibility, each of them was tested using 5 antibiotics as instructed by Clinical and Laboratory Standards Institute CLSI (2016); for disinfectant susceptibility, all the three were tested using the same 6 disinfectants, which are frequently used in poultry industry in Kenya. xix Total bacterial counts from intestinal samples ranged between 1.92x104 and 1.04x1012 colony-forming-units per milliliter (cfu/ml), with arithmetic means of 4.7x1011, 5.6x1011 and 1.3x1012 cfu/ml for Kariokor, Burma and Kangemi slaughterhouses, respectively. Escherichia coli was isolated at 85.8%, Staphylococcus spp at 55% and Streptococcus spp at 43.3%. Other bacteria, which were isolated at lower rates, included: Proteus spp, Listeria spp, Bacillus spp, Streptobacillus spp, Klebsiella spp, Campylobacter spp and Pseudomonas aeuroginosa. Escherichia coli isolates were resistant to the following antibiotics: Ampicillin at 100%, Sulphamethoxazole at 93.3%, Amoxicillin at 93.3%, Gentamycin at 13.3%; all were susceptible to Ciprofloxacin. Staphylococcus isolates were resistant to Clindamycin at 73.3%, Tetracycline at 46.7%, Chloramphenicol at 40% and were susceptible to Sulphamethoxazole and Erythromycin. Streptococcus isolates were resistant to Sulphamethoxazole, Clindamycin, Erythromycin, Tetracycline and Chloramphenicol at 93.3%, 86.7%, 60%, 60% and 53.3% respectively. The three tested isolates (Escherichia coli, Staphylococcus and Streptococcus) showed multidrug resistance at 100%; 46.7% and 93.3%, respectively. At recommended user concentration, E. coli isolates were resistant to the following coded disinfectants with their active ingredients in bracket: F (3.85% m/v of Sodium Hypochlorite) at 100%, D (Chloroxylenol 4.8%) at 26.7%, A (Glutaraldehyde 15% v/v; Benzalkonium chloride 10% v/v) at 40% and C (Glutaraldehyde 15%w/v; Coco-benzyl-dimethyl-Ammonium Chloride 10%w/v) at 46.7%. Staphylococcus isolates were resistant to F and B (Didecyl dimethyl ammonium HCl 18.75 gram; Diotyl dimethyl ammonium HCl 18.75g; Octyl decyl dimethyl ammonium HCl 37.5 gram; Alkyl dimethyl ammonium HCl 50 gram and Glutaraldehyde 62.50 gram) at 93.3% and 6.7%, respectively; Streptococcus isolates were only resistant to F at 93.3%. xx The isolates were susceptible to the remaining disinfectants. About seventy three percent (73.3%) of E. coli and 6.7 % of Staphylococcus isolates showed resistance to both antibiotic(s) and disinfectant(s). This study has demonstrated high concentration of various bacterial types in the intestinal tract of the indigenous chickens sampled after the heavy rains of year 2018, and that the isolated bacteria were variously resistant to the tested antibiotics and disinfectants. This highlights the possibility of the chickens serving as sources of pathogenic bacteria that can be transmitted to other chickens and humans; if resistant to antimicrobials, it would be difficult treating the resultant diseases. It is, therefore, recommended that chicken meat should be cooked well and that care be taken, during slaughtering of chickens since cross-contamination can occur and lead to food contamination. It is also recommended that before dispensing an antibiotic or using a disinfectant, one ascertains its susceptibility by carrying out antibiotic/disinfectant susceptibility testing and, where possible, free-range indigenous chickens be confined during rainy seasons. This data will aid policy makers come up with guidelines on reduction of environmental contamination.