Possa de Menezes Mareliza, Vedovelli Cardozo Marita, Pereira Natália, Bugov Mariana, Verbisck Newton Valerio, Castro Vanessa, Figueiredo de Castro Nassar Alessandra, Castro Moraes Paola
Department of Clinic and Veterinary Surgery, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo, 14884-900, Brazil.
Department of Pathology, Reproduction, and One Health, School of Agricultural and Veterinarian Sciences, São Paulo State University (UNESP), Jaboticabal, São Paulo, 14884-900, Brazil.
BMC Vet Res. 2025 Mar 6;21(1):147. doi: 10.1186/s12917-025-04611-4.
This prospective cross-sectional study aimed to determine the occurrence of resistance genes and genetic diversity in Staphylococcus spp., Enterococcus spp., and Escherichia coli isolated from dogs' superficial surgical site (SS), surgeons' hands, and the operating room (OR) during the intraoperative period.
Thirty dogs undergoing clean/clean-contaminated (G1, n = 20) and contaminated surgeries (G2, n = 10), along with eight surgeons, were included in the study. Specimens were collected using sterile swabs, transported in 0.1% peptone salt solution, and spread onto blood agar. Environmental samples were collected through passive exposure using BHI agar plates. Seventy-five isolates were selected and classified using MALDI-TOF MS. Resistance genes were screened via PCR: tet(M), ermA, aacA-aphD, blaZ, mecA, bla, bla, bla, bla, bla, bla, mcr, mcr, mcr, mcr, and ndm. Genetic diversity was assessed through PFGE analysis using SmaI and XbaI restriction enzymes, with clustering performed by the UPGMA method. The chi-square test compared the frequency of resistance gene detected.
Staphylococcus pseudintermedius (83.33%), Enterococcus spp. (52.63%), and E. coli (62.50%) were more frequently isolated from dogs' skin, while coagulase-negative staphylococci (CoNS; 62.50%) were more frequent in the OR. Resistance genes detected in Staphylococcus spp. included blaZ (79.17%), mecA (43.75%), tet(M) (41.67%), and aacA-aphD (25%). Among Enterococcus spp., tet(M) (78.95%) and blaZ (10.53%) were identified. S. pseudintermedius harbored tet(M) and aacA-aphD genes more frequently than CoNS. No E. coli isolates tested positive for the investigated genes. Twenty-four PFGE banding patterns were observed in CoNS (24/24), 15 in S. pseudintermedius (15/24), 4 in E. coli (4/8), and 7 in Enterococcus spp. (7/19). Genetically related S. pseudintermedius and E. coli were obtained from SS and OR in G2. Seven indistinguishable Enterococcus spp. were identified across different procedures and patients.
Our study revealed high rates of methicillin-resistant Staphylococcus spp. and tetracycline-resistant Enterococcus spp. colonizing the environment in a veterinary teaching hospital in Brazil. PFGE analysis indicated a high diversity of CoNS and Enterococcus spp. Genetically related strains in S. pseudintermedius, Enterococcus spp., and E. coli emphasize the importance of effective infection control policies to minimize the spread of resistant bacteria.
本前瞻性横断面研究旨在确定术中从犬类浅表手术部位（SS）、外科医生手部及手术室（OR）分离出的葡萄球菌属、肠球菌属和大肠杆菌中的耐药基因发生情况及遗传多样性。
本研究纳入了30只接受清洁/清洁-污染手术（G1组，n = 20）和污染手术（G2组，n = 10）的犬，以及8名外科医生。使用无菌拭子采集标本，置于0.1%蛋白胨盐溶液中运输，然后涂布于血琼脂平板上。环境样本通过使用脑心浸液（BHI）琼脂平板进行被动暴露采集。挑选出75株分离株并使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）进行分类。通过聚合酶链反应（PCR）筛选耐药基因：tet(M)、ermA、aacA-aphD、blaZ、mecA、bla、bla、bla、bla、bla、bla、mcr、mcr、mcr、mcr和ndm。使用SmaI和XbaI限制性内切酶通过脉冲场凝胶电泳（PFGE）分析评估遗传多样性，并采用非加权组平均法（UPGMA）进行聚类。采用卡方检验比较检测到的耐药基因频率。
从犬类皮肤中更频繁分离出中间型葡萄球菌（83.33%）、肠球菌属（52.63%）和大肠杆菌（62.50%），而凝固酶阴性葡萄球菌（CoNS；62.50%）在手术室中更为常见。在葡萄球菌属中检测到的耐药基因包括blaZ（79.17%）、mecA（43.75%）、tet(M)（41.67%）和aacA-aphD（25%）。在肠球菌属中，鉴定出tet(M)（78.95%）和blaZ（10.53%）。中间型葡萄球菌比CoNS更频繁地携带tet(M)和aacA-aphD基因。没有大肠杆菌分离株对所研究的基因检测呈阳性。在CoNS中观察到24种PFGE条带模式（24/24），在中间型葡萄球菌中为15种（15/24），在大肠杆菌中为4种（4/8），在肠球菌属中为7种（7/19）。在G2组中，从手术部位和手术室获得了基因相关的中间型葡萄球菌和大肠杆菌。在不同手术程序和患者中鉴定出7株无法区分的肠球菌属。
我们研究揭示了巴西一家兽医教学医院环境中耐甲氧西林葡萄球菌属和耐四环素肠球菌属的高定植率。PFGE分析表明CoNS和肠球菌属具有高度多样性。中间型葡萄球菌、肠球菌属和大肠杆菌中的基因相关菌株强调了有效感染控制策略对于最大限度减少耐药菌传播的重要性。
