Gamuya Ezekiel, Salum Mulki S, Mtewele Beatrice Augustino, Minja Baraka, Damiano Prisca, Mtemisika Conjester I, Mnibi Kulwa P, Abednego Reuben N, Okamo Bernard C, Silago Vitus, Mshana Stephen E, Claus Heike, Seni Jeremiah
Department of Microbiology and Immunology, Weill Bugando School of Medicine, Catholic University of Health and Allied Sciences, P. O. Box 1464, Mwanza, Tanzania.
Department of Microbiology, National Public Health Laboratory, P. O. Box 9083, Dar es Salaam, Tanzania.
Infect Prev Pract. 2025 Jul 5;7(3):100475. doi: 10.1016/j.infpip.2025.100475. eCollection 2025 Sep.
Hospital surfaces are critical reservoirs of multidrug-resistant pathogens, including third-generation cephalosporin-resistant Gram-negative bacteria (3GC-R-GNB), significantly contributing to healthcare-associated infections (HCAIs). This challenge is pronounced in low- and middle-income countries, where resource constraints limit effective infection prevention and control (IPC) measures. This study screened hospital surfaces for 3GC-R-GNB in selected District Hospitals (DHs) in Mwanza, Tanzania.
This cross-sectional hospital-based study was conducted between June and July, 2023. Door handles, hand-washing sinks, patients' beds, and ward floors were sampled. Isolation of 3GC-R-GNB was done on MacConkey agar supplemented with cefotaxime (2 μg/ml). Bacterial identification was done by MALDI-TOF on Vitek MS while antimicrobial susceptibility testing was done by the Kirby-Bauer method. A multiplex PCR assay was applied for the detection of extended-spectrum beta-lactamase (ESBL) genes ( , , and ).
A total of 892 swabs were collected from hospital surfaces, of which 243 (27.2%) were 3GC-R-GNB positive. From the 243 positive samples, 55 samples exhibited polymicrobial growth making a total of 300 bacterial isolates. The most prevalent species was (26.0%, 78/300), followed by (11.0%, 33/300), (8.0%, 24/300), and (7.0%, 21/300). Multiplex PCR of selected isolates (n=243) revealed that 99.6% (242/243), 93.4% (227/243), and 2.9% (7/243) 3GC-R-GNB harbored , , and genes encoding ESBLs, respectively.
This study reveals substantial dispersion of highly resistant Gram-negative bacteria to hospital surfaces, showing the need to prevent dispersion of such contamination and targeted hospital hygiene measures to protect patients.
医院环境表面是多重耐药病原体的重要储存库，包括耐第三代头孢菌素的革兰氏阴性菌（3GC-R-GNB），对医疗相关感染（HCAIs）有显著影响。在低收入和中等收入国家，这一挑战尤为突出，因为资源限制阻碍了有效的感染预防和控制（IPC）措施。本研究在坦桑尼亚姆万扎的选定地区医院（DHs）对医院环境表面进行了3GC-R-GNB筛查。
本横断面医院研究于2023年6月至7月进行。对门把手、洗手池、患者病床和病房地面进行采样。在添加头孢噻肟（2μg/ml）的麦康凯琼脂上分离3GC-R-GNB。通过Vitek MS上的基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）进行细菌鉴定，同时通过 Kirby-Bauer 方法进行药敏试验。应用多重PCR检测超广谱β-内酰胺酶（ESBL）基因（ 、 和 ）。
共从医院环境表面采集了892份拭子，其中243份（27.2%）为3GC-R-GNB阳性。在243份阳性样本中，55份呈现多菌生长，共计300株细菌分离株。最常见的菌种是 （26.0%，78/300），其次是 （11.0%，33/300）、 （8.0%，24/300）和 （7.0%，21/300）。对选定分离株（n = 243）进行的多重PCR显示，99.6%（242/243）、93.4%（227/243）和2.9%（7/243）的3GC-R-GNB分别携带编码ESBL的 、 和 基因。
本研究揭示了高耐药革兰氏阴性菌在医院环境表面的大量扩散，表明需要防止此类污染的扩散并采取针对性的医院卫生措施以保护患者。
