Vasco Karla, Graham Jay P, Trueba Gabriel
Microbiology Institute, Colegio de Ciencias Biologicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador.
Milken Institute School of Public Health, George Washington University, Washington, DC, USA.
Appl Environ Microbiol. 2016 Jun 30;82(14):4218-4224. doi: 10.1128/AEM.00795-16. Print 2016 Jul 15.
Animals are important reservoirs of zoonotic enteropathogens, and transmission to humans occurs more frequently in low- and middle-income countries (LMICs), where small-scale livestock production is common. In this study, we investigated the presence of zoonotic enteropathogens in stool samples from 64 asymptomatic children and 203 domestic animals of 62 households in a semirural community in Ecuador between June and August 2014. Multilocus sequence typing (MLST) was used to assess zoonotic transmission of Campylobacter jejuni and atypical enteropathogenic Escherichia coli (aEPEC), which were the most prevalent bacterial pathogens in children and domestic animals (30.7% and 10.5%, respectively). Four sequence types (STs) of C. jejuni and four STs of aEPEC were identical between children and domestic animals. The apparent sources of human infection were chickens, dogs, guinea pigs, and rabbits for C. jejuni and pigs, dogs, and chickens for aEPEC. Other pathogens detected in children and domestic animals were Giardia lamblia (13.1%), Cryptosporidium parvum (1.1%), and Shiga toxin-producing E. coli (STEC) (2.6%). Salmonella enterica was detected in 5 dogs and Yersinia enterocolitica was identified in 1 pig. Even though we identified 7 enteric pathogens in children, we encountered evidence of active transmission between domestic animals and humans only for C. jejuni and aEPEC. We also found evidence that C. jejuni strains from chickens were more likely to be transmitted to humans than those coming from other domestic animals. Our findings demonstrate the complex nature of enteropathogen transmission between domestic animals and humans and stress the need for further studies.
We found evidence that Campylobacter jejuni, Giardia, and aEPEC organisms were the most common zoonotic enteropathogens in children and domestic animals in a region close to Quito, the capital of Ecuador. Genetic analysis of the isolates suggests transmission of some genotypes of C. jejuni and aEPEC from domestic animals to humans in this region. We also found that the genotypes associated with C. jejuni from chickens were present more often in children than were those from other domestic animals. The potential environmental factors associated with transmission of these pathogens to humans then are discussed.
动物是人畜共患肠道病原体的重要宿主,在小规模畜牧生产常见的低收入和中等收入国家(LMICs),病原体向人类的传播更为频繁。在本研究中,我们调查了2014年6月至8月期间,厄瓜多尔一个半农村社区62户家庭中64名无症状儿童和203只家畜粪便样本中的人畜共患肠道病原体。采用多位点序列分型(MLST)评估空肠弯曲菌和非典型肠致病性大肠杆菌(aEPEC)的人畜共患传播情况,这两种细菌是儿童和家畜中最常见的细菌病原体(分别为30.7%和10.5%)。儿童和家畜中,空肠弯曲菌的4个序列型(STs)和aEPEC的4个STs相同。空肠弯曲菌感染人类的明显来源是鸡、狗、豚鼠和兔子,aEPEC的感染来源是猪、狗和鸡。在儿童和家畜中检测到的其他病原体有蓝氏贾第鞭毛虫(13.1%)、微小隐孢子虫(1.1%)和产志贺毒素大肠杆菌(STEC)(2.6%)。在5只狗中检测到肠炎沙门氏菌,在1头猪中鉴定出小肠结肠炎耶尔森菌。尽管我们在儿童中鉴定出7种肠道病原体,但仅发现空肠弯曲菌和aEPEC在家畜和人类之间有活跃传播的证据。我们还发现,来自鸡的空肠弯曲菌菌株比来自其他家畜的菌株更有可能传播给人类。我们的研究结果证明了家畜和人类之间肠道病原体传播的复杂性,并强调了进一步研究的必要性。
我们发现证据表明,在厄瓜多尔首都基多附近的一个地区,空肠弯曲菌、贾第虫和aEPEC是儿童和家畜中最常见的人畜共患肠道病原体。对分离株的基因分析表明,该地区空肠弯曲菌和aEPEC的一些基因型在家畜和人类之间传播。我们还发现,与来自鸡的空肠弯曲菌相关的基因型在儿童中出现的频率高于来自其他家畜的基因型。随后讨论了与这些病原体传播给人类相关的潜在环境因素。