College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O. Box 7062, Kampala, Uganda.
College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, P.O. Box 7062, Kampala, Uganda.
Prev Vet Med. 2014 Jul 1;115(1-2):39-47. doi: 10.1016/j.prevetmed.2014.03.009. Epub 2014 Mar 18.
Non-typhoidal salmonellosis is of concern in humans in sub-Saharan Africa, and this is partly due to the high number of immunocompromised persons. Pork and pork products could be among the sources of these non-typhi Salmonella spp. The aim of this study was to identify Salmonella spp. in piglets and weaners in northern and eastern Uganda, characterize their antimicrobial resistance patterns and determine herd-level risk factors. Fecal samples were collected from 465 piglets and weaners from 93 herds (49 and 44 from northern and eastern Uganda, respectively). In addition, information about the herd management and potential risk factors were collected. The fecal samples were cultured for the identification of Salmonella spp. The Salmonella spp. confirmed by serotyping were further characterized by determination of minimum inhibitory concentration (MIC) to 12 antimicrobials by broth microdilution. At individual level, the total prevalence of Salmonella spp. was 12% (12.2% in northern and 11.9% in eastern Uganda). At herd level, the total prevalence was 39% (43% in northern and 34% in eastern Uganda). From 56 samples with Salmonella spp., 20 serovars were identified including two serovars identified only by their antigenic formulae. The predominant serovars were S. Zanzibar, S. Heidelberg, S. Infantis, S. Typhimurium, S. Stanleyville, S. Aberdeen and S. Kampala. In total, 57% of the 53 Salmonella spp. analyzed, originating from 27% of the herds, were resistant to at least one antimicrobial agent. The majority of drug-resistant isolates (60%) were from northern Uganda. Eight multidrug-resistant (MDR) isolates were from northern Uganda and three MDR isolates were from eastern Uganda. Increased prevalence of Salmonella spp. was associated with feeding the young and adults separately as compared to feeding the young and adults together (p=0.043, OR=4.3; 95% CI 1.1, 17.38). Protective factors were "intensive" method of keeping the pigs versus "tethering and roaming" (p=0.016, OR=0.11; 95% CI 0.02, 0.64), "intensive" method versus "semi-intensive" method (p=0.048, OR=0.12; 95% CI 0.01, 0.96) and cleaning feeders after every two days versus daily (p=0.017, OR=0.18; 95% CI 0.05, 0.72). This study has revealed a high prevalence of infection of piglets and weaners with diverse non-typhi Salmonella serovars and highlights the potential role of pork and pork products as sources of these organisms for humans. In addition, this study has identified protective factors that could be promoted to control Salmonella spp. and in antimicrobial resistance reduction programs in rural pigs from Uganda.
在撒哈拉以南非洲，非伤寒沙门氏菌对人类健康构成威胁，这在一定程度上是由于免疫功能低下人群数量较多。猪肉和猪肉产品可能是这些非伤寒沙门氏菌的来源之一。本研究旨在确定乌干达北部和东部仔猪和断奶仔猪中的沙门氏菌，对其抗菌药物耐药模式进行特征描述，并确定群体水平的风险因素。从 93 个群体（北部和东部分别为 49 和 44 个）的 465 头仔猪和断奶仔猪中采集粪便样本。此外，还收集了有关群体管理和潜在风险因素的信息。对粪便样本进行培养以鉴定沙门氏菌。通过肉汤微量稀释法测定 12 种抗菌药物的最低抑菌浓度（MIC），对血清型鉴定确认的沙门氏菌进行进一步特征描述。在个体水平上，沙门氏菌的总流行率为 12%（北部为 12.2%，东部为 11.9%）。在群体水平上，总流行率为 39%（北部为 43%，东部为 34%）。从 56 份含有沙门氏菌的样本中，鉴定出 20 种血清型，其中包括两种仅根据其抗原配方确定的血清型。主要的血清型为 S. Zanzibar、S. Heidelberg、S. Infantis、S. Typhimurium、S. Stanleyville、S. Aberdeen 和 S. Kampala。在分析的 53 株沙门氏菌中，有 57%至少对一种抗菌药物具有耐药性，其中 27%的菌株来自 27%的群体。大多数耐药分离株（60%）来自乌干达北部。8 株多重耐药（MDR）分离株来自乌干达北部，3 株 MDR 分离株来自乌干达东部。与同时喂养仔猪和成年猪相比，单独喂养仔猪和成年猪的沙门氏菌感染流行率更高（p=0.043，OR=4.3；95%CI 1.1，17.38）。保护因素为“集约化”饲养方式与“拴系和漫游”饲养方式（p=0.016，OR=0.11；95%CI 0.02，0.64）、“集约化”饲养方式与“半集约化”饲养方式（p=0.048，OR=0.12；95%CI 0.01，0.96）以及每两天清洁一次饲料器与每天清洁（p=0.017，OR=0.18；95%CI 0.05，0.72）。本研究表明，仔猪和断奶仔猪中非伤寒沙门氏菌血清型的感染率很高，这突出了猪肉和猪肉产品可能成为人类这些生物体的来源。此外，本研究还确定了一些保护因素，可在乌干达农村猪群中用于控制沙门氏菌和减少抗菌药物耐药性。
