Unit of Biomedical Sciences, College of Veterinary Medicine and Animal Sciences, University of Gondar, P O. box: 196, Gondar, Ethiopia.
Department of Medical Microbiology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, P O. box: 196, Gondar, Ethiopia.
BMC Microbiol. 2021 Nov 8;21(1):309. doi: 10.1186/s12866-021-02378-w.
The hospital environment serves as a source of nosocomial infections, which pose a major therapeutic challenge. Although many bacteria species are common in hospital environments, their distribution, frequency, and antimicrobial susceptibility pattern from high-touch surfaces, leftover drugs, and antiseptics in different wards remain largely unknown. Hence, the aim of this study was to assess the magnitude and frequency of bacterial contaminants and their antimicrobial susceptibility patterns.
A total of 384 samples were collected from five selected wards and processed according to standard bacteriological procedures. Samples were collected from high-touch surface using swabs and inoculated on Blood agar, MacConkey agar, Chocolate agar and Mannitol salt agar plates, and incubated at 37 °C for 24 h. On the other hand, the leftover drugs and 80% ethanol samples were collected using sterile cotton swab immersed in sterile tryptone soy broth then inoculated on culture medias and incubated at 37 °C for 24 h. Identification of bacteria species was done using the morphological characteristics, Gram stain, and biochemical tests while antimicrobial susceptibility tests were done using modified Kirby-Bauer disk diffusion technique following the Clinical Laboratory Standards Institute 2021guidelines.
Among the 384 samples processed, 102 (26.6%) were culture positive and a total of 114 bacterial isolates were identified. Gram-positive bacterial isolates were predominant, 64.9%, while Gram-negatives were 35.1%. The most frequently isolated bacteria were coagulase negative Staphylococci (38.6%) followed by S. aureus (13.2%) and P. aeruginosa (11.4%). On the other hand, the proportion of bacteria isolated from surgical ward, post-natal ward, orthopedic ward, trauma ward, and neonatal intensive care unit ward were 24.6, 21, 20.2, 18.4,15.8%, respectively. Sinks were mainly contaminated with Klebsiella species (81.8%) and A. baumannii (55.6%), while A. baumannii (22.2%) was the most contaminant for 80% ethanol. Gram-positive bacteria had significantly high resistance levels to penicillin (67.6%), cotrimoxazole (67.8%), and cefepime (80%). On the other hand, Gram-negative bacteria revealed the highest resistance levels to tetracycline (82.4%), amoxicillin-clavulanic acid (76.5%), cefepime (66.7%), ceftazidime (67.5%), and piperacillin (92.3%). Moreover, the proportion of multidrug resistant bacteria isolates was 44.7%.
Data of the present study showed that coagulase negative Staphylococci was the dominant bacterial isolates followed by S. aureus and P. aeruginosa. The proportion of multi-drug resistant bacteria isolates was relatively high. Therefore, appropriate infection prevention and control measures should be implemented.
医院环境是医院感染的源头,这对治疗构成了重大挑战。尽管许多细菌种类在医院环境中很常见,但它们在不同病房的高接触表面、剩余药物和防腐剂中的分布、频率和抗生素敏感性模式在很大程度上仍然未知。因此,本研究的目的是评估细菌污染物的程度和频率及其抗生素敏感性模式。
从五个选定的病房共采集 384 个样本,并按照标准细菌学程序进行处理。使用拭子从高接触表面采集样本,并接种于血琼脂、麦康凯琼脂、巧克力琼脂和甘露醇盐琼脂平板上,在 37°C 下孵育 24 小时。另一方面,使用无菌拭子从剩余药物和 80%乙醇样本中采集,并将其浸入无菌胰蛋白酶大豆肉汤中,然后接种于培养介质中,在 37°C 下孵育 24 小时。使用形态特征、革兰氏染色和生化试验对细菌种类进行鉴定,同时使用改良 Kirby-Bauer 纸片扩散技术根据临床实验室标准研究所 2021 年指南进行抗生素敏感性试验。
在所处理的 384 个样本中,有 102 个(26.6%)培养阳性,共鉴定出 114 个细菌分离株。革兰氏阳性细菌分离株占优势,为 64.9%,而革兰氏阴性细菌为 35.1%。最常分离的细菌是凝固酶阴性葡萄球菌(38.6%),其次是金黄色葡萄球菌(13.2%)和铜绿假单胞菌(11.4%)。另一方面,从外科病房、产后病房、骨科病房、创伤病房和新生儿重症监护病房采集的细菌比例分别为 24.6%、21%、20.2%、18.4%和 15.8%。水槽主要受到克雷伯菌属(81.8%)和鲍曼不动杆菌(55.6%)的污染,而 80%乙醇中最主要的污染物是鲍曼不动杆菌(22.2%)。革兰氏阳性菌对青霉素(67.6%)、复方新诺明(67.8%)和头孢吡肟(80%)的耐药率显著较高。另一方面,革兰氏阴性菌对四环素(82.4%)、阿莫西林克拉维酸(76.5%)、头孢吡肟(66.7%)、头孢他啶(67.5%)和哌拉西林(92.3%)的耐药率最高。此外,多药耐药菌分离株的比例为 44.7%。
本研究的数据表明,凝固酶阴性葡萄球菌是主要的细菌分离株,其次是金黄色葡萄球菌和铜绿假单胞菌。多药耐药菌分离株的比例相对较高。因此,应采取适当的感染预防和控制措施。