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Abstract：
BACKGROUND: Acinetobacter baumannii is an opportunistic pathogen that can cause a variety of nosocomial infections in humans. This study aimed to molecularly characterize extended-spectrum beta-lactamase (ESBL) producing and carbapenem-resistant Acinetobacter species isolated from surgical site infections (SSI).
METHODS: A multicentre cross-sectional study was performed among SSI patients at four hospitals located in Northern, Southern, Southwest, and Central parts of Ethiopia. The isolates were identified by microbiological methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility was determined using disk diffusion. The presence of phenotypic ESBL and carbapenemase production was detected by employing standard microbiological tests, including combined disk diffusion (CDT). ESBL and carbapenem resistance determinants genes were studied by polymerase chain reaction (PCR) and sequencing.
RESULTS: A total of 8.7% Acinetobacter species were identified from 493 culture-positive isolates out of 752 SSI wounds. The species identified by MALDI-TOF MS were 88.4% A. baumannii, 4.7% Acinetobacter pittii, 4.7% Acinetobacter soli, and 2.3% Acinetobacter lactucae. Of all isolates 93% were positive for ESBL enzymes according to the CDT. Using whole genome sequencing 62.8% of the A. baumannii harbored one or more beta-lactamase genes, and 46.5% harbored one or more carbapenemase producing genes. The distribution of beta-lactamases among Acinetobacter species by hospitals was 53.8%, 64.3%, 75%, and 75% at JUSH, TASH, DTCSH, and HUCSH respectively. Among ESBL genes, blaCTX-M alleles were detected in 21.4% of isolates; of these 83.3% were blaCTX-M-15. The predominant carbapenemase gene of blaOXA type was detected in 24 carbapenem-resistant A. baumannii followed by blaNDM alleles carried in 12 A. baumannii with blaNDM-1 as the most common.
CONCLUSIONS: The frequency of Acinetobacter species that produce metallobetalactamases (MBLs) and ESBLs that were found in this study is extremely scary and calls for strict infection prevention and control procedures in health facilities helps to set effective antibiotics stewardship.
METHODS: A multicentre cross-sectional study was performed among SSI patients at four hospitals located in Northern, Southern, Southwest, and Central parts of Ethiopia. The isolates were identified by microbiological methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility was determined using disk diffusion. The presence of phenotypic ESBL and carbapenemase production was detected by employing standard microbiological tests, including combined disk diffusion (CDT). ESBL and carbapenem resistance determinants genes were studied by polymerase chain reaction (PCR) and sequencing.
RESULTS: A total of 8.7% Acinetobacter species were identified from 493 culture-positive isolates out of 752 SSI wounds. The species identified by MALDI-TOF MS were 88.4% A. baumannii, 4.7% Acinetobacter pittii, 4.7% Acinetobacter soli, and 2.3% Acinetobacter lactucae. Of all isolates 93% were positive for ESBL enzymes according to the CDT. Using whole genome sequencing 62.8% of the A. baumannii harbored one or more beta-lactamase genes, and 46.5% harbored one or more carbapenemase producing genes. The distribution of beta-lactamases among Acinetobacter species by hospitals was 53.8%, 64.3%, 75%, and 75% at JUSH, TASH, DTCSH, and HUCSH respectively. Among ESBL genes, blaCTX-M alleles were detected in 21.4% of isolates; of these 83.3% were blaCTX-M-15. The predominant carbapenemase gene of blaOXA type was detected in 24 carbapenem-resistant A. baumannii followed by blaNDM alleles carried in 12 A. baumannii with blaNDM-1 as the most common.
CONCLUSIONS: The frequency of Acinetobacter species that produce metallobetalactamases (MBLs) and ESBLs that were found in this study is extremely scary and calls for strict infection prevention and control procedures in health facilities helps to set effective antibiotics stewardship.
摘要：
背景：鲍曼不动杆菌是一种机会性病原体，可引起人类多种医院感染。这项研究旨在对从手术部位感染（SSI）中分离出的产超广谱β-内酰胺酶（ESBL）和耐碳青霉烯的不动杆菌进行分子表征。
方法：对位于北部的四家医院的SSI患者进行了一项多中心横断面研究，南方,西南，和埃塞俄比亚中部地区。通过微生物学方法和基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）鉴定了分离株。使用圆盘扩散确定抗生素敏感性。通过使用标准的微生物测试来检测表型ESBL和碳青霉烯酶的产生。包括组合磁盘扩散(CDT)。通过聚合酶链反应（PCR）和测序研究了ESBL和碳青霉烯抗性决定基因。
结果：从752个SSI伤口中的493个培养阳性分离株中鉴定出总共8.7%的不动杆菌。通过MALDI-TOFMS鉴定的物种为88.4％鲍曼不动杆菌，4.7%皮氏不动杆菌，4.7%固体不动杆菌，和2.3%的乳酸不动杆菌。根据CDT，在所有分离物中，有93％的ESBL酶呈阳性。使用全基因组测序，62.8％的鲍曼不动杆菌具有一个或多个β-内酰胺酶基因，46.5%的人携带一种或多种碳青霉烯酶产生基因。医院不动杆菌中β-内酰胺酶的分布为53.8%,64.3%,75%,JUSH的75%，塔什,DTCSH,和HUCSH分别。在ESBL基因中，在21.4％的分离株中检测到blaCTX-M等位基因；其中83.3％是blaCTX-M-15。在24个耐碳青霉烯的鲍曼不动杆菌中检测到blaOXA型的主要碳青霉烯酶基因，其次是在12个鲍曼不动杆菌中携带的blaNDM等位基因，最常见的是blaNDM-1。
结论：本研究中发现的不动杆菌产生金属β内酰胺酶（MBL）和ESBLs的频率非常可怕，要求在医疗机构中严格的感染预防和控制程序有助于建立有效的抗生素管理。
方法：对位于北部的四家医院的SSI患者进行了一项多中心横断面研究，南方,西南，和埃塞俄比亚中部地区。通过微生物学方法和基质辅助激光解吸/电离飞行时间质谱（MALDI-TOFMS）鉴定了分离株。使用圆盘扩散确定抗生素敏感性。通过使用标准的微生物测试来检测表型ESBL和碳青霉烯酶的产生。包括组合磁盘扩散(CDT)。通过聚合酶链反应（PCR）和测序研究了ESBL和碳青霉烯抗性决定基因。
结果：从752个SSI伤口中的493个培养阳性分离株中鉴定出总共8.7%的不动杆菌。通过MALDI-TOFMS鉴定的物种为88.4％鲍曼不动杆菌，4.7%皮氏不动杆菌，4.7%固体不动杆菌，和2.3%的乳酸不动杆菌。根据CDT，在所有分离物中，有93％的ESBL酶呈阳性。使用全基因组测序，62.8％的鲍曼不动杆菌具有一个或多个β-内酰胺酶基因，46.5%的人携带一种或多种碳青霉烯酶产生基因。医院不动杆菌中β-内酰胺酶的分布为53.8%,64.3%,75%,JUSH的75%，塔什,DTCSH,和HUCSH分别。在ESBL基因中，在21.4％的分离株中检测到blaCTX-M等位基因；其中83.3％是blaCTX-M-15。在24个耐碳青霉烯的鲍曼不动杆菌中检测到blaOXA型的主要碳青霉烯酶基因，其次是在12个鲍曼不动杆菌中携带的blaNDM等位基因，最常见的是blaNDM-1。
结论：本研究中发现的不动杆菌产生金属β内酰胺酶（MBL）和ESBLs的频率非常可怕，要求在医疗机构中严格的感染预防和控制程序有助于建立有效的抗生素管理。
