Leite Suzana, Cotias Carlos, Rainha Kelly C, Santos Mayara Gil, Penna Bruno, F Moraes Renata F, Harmanus Céline, Smits Wiep Klaas, Ferreira Eliane de Oliveira
Departmento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes -IMPG, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Universidade Santa Úrsula, Rio de Janeiro, Brazil.
H&Diagnóstico, Veterinary Diagnosis Center, Rio de Janeiro, Brazil.
Anaerobe. 2023 Oct;83:102765. doi: 10.1016/j.anaerobe.2023.102765. Epub 2023 Aug 12.
Clostridioides difficile infections (CDI) have a high morbidity and mortality rate and have always been considered a nosocomial disease. Nonetheless, the number of cases of community-acquired CDI is increasing, and new evidence suggests additional C. difficile reservoirs exist. Pathogenic C. difficile strains have been found in livestock, domestic animals, and meat, so a zoonotic transmission has been proposed.
The goal of this study was to isolate C. difficile strains in dogs at a veterinary clinic in Rio de Janeiro, Brazil, and characterize clinical and pathological findings associated with lower gastrointestinal tract disorders.
Fifty stool samples and biopsy fragments from dogs were obtained and cultured in the CDBA selective medium. All suggestive C. difficile colonies were confirmed by MALDI-TOF MS and PCR (tpi gene). Vancomycin, metronidazole, moxifloxacin, erythromycin, and rifampicin were tested for antibiotic susceptibility. Biofilm, motility assays, and a PCR for the toxins (tcdA, tcdB, and cdtB), as well as ribotyping, were also performed.
Blood samples and colonic biopsy fragments were examined in C. difficile positive dogs. Ten animals (20%) tested positive for C. difficile by using stool samples, but not from biopsy fragments. Most C. difficile strains were toxigenic: six were A+B+ belonging to RT106; two were A+B+ belonging to RT014/020; and two were A-B- belonging to RT010. All strains were biofilm producers. In the motility test, 40% of strains were as motile as the positive control, CD630 (RT012). In the disc diffusion test, two strains (RT010) were resistant to erythromycin and metronidazole; and another to metronidazole (RT014/020). In terms of C. difficile clinicopathological correlations, no statistically significant morphological changes, such as pseudomembranous and "volcano" lesions, were observed. Regarding hematological data, dogs positive for C. difficile had leucopenia (p = 0.02) and lymphopenia (p = 0.03). There was a significant correlation between senility and the presence of C. difficile in the dogs studied (p = 0,02).
Although C. difficile has not been linked to canine diarrheal disorders, it appears to be more common in dogs with intestinal dysfunctions. The isolation of ribotypes frequently involved in human CDI outbreaks around the world supports the theory of C. difficile zoonotic transmission.
艰难梭菌感染（CDI）具有较高的发病率和死亡率，一直被认为是一种医院感染性疾病。尽管如此，社区获得性CDI的病例数正在增加，新的证据表明存在其他艰难梭菌储存库。在牲畜、家畜和肉类中发现了致病性艰难梭菌菌株，因此有人提出了人畜共患病传播的观点。
本研究的目的是在巴西里约热内卢的一家兽医诊所分离犬类中的艰难梭菌菌株，并对与下消化道疾病相关的临床和病理结果进行特征描述。
从犬类获取50份粪便样本和活检碎片，在CDBA选择性培养基中培养。所有疑似艰难梭菌菌落通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）和聚合酶链反应（PCR，tpi基因）进行确认。测试了万古霉素、甲硝唑、莫西沙星、红霉素和利福平的抗生素敏感性。还进行了生物膜、运动性测定以及毒素（tcdA、tcdB和cdtB）的PCR检测，以及核糖体分型。
对艰难梭菌阳性犬进行了血液样本和结肠活检碎片检查。10只动物（20%）粪便样本艰难梭菌检测呈阳性，但活检碎片检测未呈阳性。大多数艰难梭菌菌株具有产毒素能力：6株为A+B+型，属于RT106；2株为A+B+型，属于RT014/020；2株为A-B-型，属于RT010。所有菌株均为生物膜产生菌。在运动性试验中，40%的菌株运动能力与阳性对照CD630（RT012）相同。在纸片扩散试验中，2株菌株（RT010）对红霉素和甲硝唑耐药；另1株对甲硝唑耐药（RT014/020）。在艰难梭菌临床病理相关性方面，未观察到统计学上显著的形态学变化，如假膜性和“火山”样病变。关于血液学数据，艰难梭菌阳性犬有白细胞减少（p = 0.02）和淋巴细胞减少（p = 0.03）。在所研究的犬类中，衰老与艰难梭菌的存在之间存在显著相关性（p = 0.02）。
尽管艰难梭菌与犬类腹泻疾病没有关联，但在肠道功能障碍的犬类中似乎更为常见。在世界各地人类CDI暴发中经常涉及的核糖体分型的分离支持了艰难梭菌人畜共患病传播的理论。
