Meireles Júlia, Moraes Renata F F, Lins Débora, Oliveira Thaís da Silveira, de Carvalho Eduardo Butturini, Rainha Kelly, Ferreira Eliane de O
Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, IMPG, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Universidade de Vassouras, Vassouras, Brazil.
Anaerobe. 2024 Dec;90:102917. doi: 10.1016/j.anaerobe.2024.102917. Epub 2024 Oct 10.
In the past decade, the incidence of community-acquired Clostridioides difficile infection (CA-CDI) has increased, suggesting a role for community reservoirs such as animals in its spread.
This study aimed to isolate and characterize C. difficile strains from domestic dogs at veterinary clinics to enhance our understanding of C. difficile epidemiology in Rio de Janeiro.
For this study 90 stool samples from dogs were collected and cultured in a selective medium (Clostridioides difficile Brucella agar - CDBA) for isolation. Species were identified by MALDI-TOF MS, with confirmation provided by PCR targeting the tpi gene. The antibiotic susceptibility test of the strains was performed using five antibiotics: vancomycin, metronidazole, moxifloxacin, rifampicin, and erythromycin. Strains resistant to metronidazole were further analyzed for the presence of the plasmid pCD-METRO using PCR. The presence of toxin genes (tcdA, tcdB, and cdtB) was investigated, alongside ribotyping and tcdC sequencing analyses. The strains were also tested for biofilm formation and motility.
C. difficile was isolated in 15.5 % (14/90) of the samples. Among the strains analyzed, 87.71 % (12/14) tested positive for both toxin genes tcdA and tcdB and belonged to ribotypes 106 (10/14) and 014/020 (2/14). The remaining 14.3 % (2/14) were non-toxigenic and were identified as ribotype 010. Regarding the antibiotic profile, 42.85 % (6/14) of the strains exhibited resistance to at least one antibiotic, including vancomycin (1/14) and metronidazole (1/14). The metronidazole-resistant strain was also positive for the plasmid pCD-METRO. All strains exhibited both biofilm formation and motility. Among the 12 toxigenic strains sequenced for the tcdC gene, two exhibited a deletion in the same region as the epidemic strain, NAP1 (RT027).
Our study found some overlap between C. difficile ribotypes isolated from dogs and from cases of CDI in humans, and the C. difficile prevalence was higher in dogs with diarrhea (p = 0.034).
在过去十年中，社区获得性艰难梭菌感染（CA-CDI）的发病率有所上升，这表明动物等社区宿主在其传播中发挥了作用。
本研究旨在从兽医诊所的家犬中分离并鉴定艰难梭菌菌株，以增进我们对里约热内卢艰难梭菌流行病学的了解。
本研究收集了90份犬类粪便样本，并在选择性培养基（艰难梭菌布鲁氏菌琼脂 - CDBA）中培养以进行分离。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）鉴定菌种，并通过靶向tpi基因的PCR进行确认。使用五种抗生素对菌株进行药敏试验：万古霉素、甲硝唑、莫西沙星、利福平及红霉素。对耐甲硝唑的菌株进一步使用PCR分析质粒pCD-METRO的存在情况。研究毒素基因（tcdA、tcdB和cdtB）的存在情况，同时进行核糖体分型和tcdC测序分析。还对菌株进行生物膜形成和运动性测试。
在15.5%（14/90）的样本中分离出艰难梭菌。在分析的菌株中，87.71%（12/14）的tcdA和tcdB两种毒素基因检测均呈阳性，属于核糖体分型106（10/14）和014/020（2/14）。其余14.3%（2/14）为非产毒菌株，被鉴定为核糖体分型010。关于抗生素谱，42.85%（6/14）的菌株对至少一种抗生素耐药，包括万古霉素（1/14）和甲硝唑（1/14）。耐甲硝唑的菌株质粒pCD-METRO也呈阳性。所有菌株均表现出生物膜形成和运动性。在对tcdC基因进行测序的12株产毒菌株中，有两株在与流行菌株NAP1（RT027）相同的区域出现缺失。
我们的研究发现，从犬类中分离出的艰难梭菌核糖体分型与人类CDI病例中的存在一些重叠，并且腹泻犬的艰难梭菌患病率更高（p = 0.034）。
