title: Multidrug-Resistant Salmonella Isolates from Swine in the Eastern Cape Province, South Africa.
abstract: The exposure of farm animals to antimicrobials for treatment, prophylaxis, or growth promotion can select for resistant bacteria that can be transmitted to humans, and Salmonella as an important zoonotic pathogen can act as a potential reservoir of antimicrobial resistance determinants. We assessed the antibiogram profiles of Salmonella species isolated from pig herds in two commercial farms in South Africa. Two hundred fifty-eight presumptive Salmonella isolates were recovered from the fecal samples of 500 adult pigs. Specific primers targeting Salmonella serogroups A, B, C1, C2, and D were used to determine the prevalence of different serogroups. Only serogroup A (n = 48) was detected, while others were not. Antimicrobial susceptibility of the confirmed Salmonella serogroup A isolates was performed by using the disk diffusion method against a panel of 18 antibiotics. All the 48 isolates were resistant to tetracycline and oxytetracycline, while 75% were resistant to ampicillin, sulphamethoxazole-trimethoprim, nalidixic acid, and streptomycin. All the isolates exhibited multidrug resistance, with the predominant phenotype being against 11 antibiotics, and multiple antibiotic resistance index ranged between 0.3 and 0.6. The incidence of genes encoding resistance against ampicillin (ampC), tetracycline (tetA), and streptomycin (strA) were 54, 61, and 44%, respectively. We conclude that healthy pigs are potential reservoirs of multidrug-resistant Salmonella that could be transmitted to humans through the food chain and, hence, a significant public health threat.
authors.affiliation: South African Medical Research Council Microbial Water Quality Monitoring Centre, , University of Fort Hare, Alice 5700, Eastern Cape, South Africa; Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, Eastern Cape, South Africa. chinwelolo@gmail.com.
authors.forename: Chinwe Juliana
authors.initials: CJ
authors.lastname: Iwu
authors.affiliation: South African Medical Research Council Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, Eastern Cape, South Africa;Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, Eastern Cape, South Africa.
authors.forename: Benson Chuks
authors.initials: BC
authors.lastname: Iweriebor
authors.affiliation: Academic and Research Division, University of Fort Hare, Alice 5700, Eastern Cape, South Africa.
authors.forename: Larry Chikwelu
authors.initials: LC
authors.lastname: Obi
authors.affiliation: Department of Biochemistry and Microbiology, University of Zululand, KwaDlangezwa, 3886, South Africa.
authors.forename: Albertus Kotze
authors.initials: AK
authors.lastname: Basson
authors.affiliation: South African Medical Research Council Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice 5700, Eastern Cape, South Africa; Applied and Environmental Microbiology Research Group, Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, Eastern Cape, South Africa.
authors.forename: Anthony Ifeanyi
authors.initials: AI
authors.lastname: Okoh
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D012475:Salmonella / Q000302:isolation & purification*; D012481:Salmonella Infections, Animal / Q000382:microbiology; D013019:South Africa; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents