Salamat Sonia, Ejaz Hasan, Zafar Aizza, Javed Humera
Sonia Salamat, M.Phil. Department of Microbiology, Government College University, Lahore, Pakistan.
Hasan Ejaz, PhD, Department of Microbiology, The Children's Hospital and The Institute of Child Health, Lahore, Pakistan.
Pak J Med Sci. 2016 Nov-Dec;32(6):1512-1516. doi: 10.12669/pjms.326.10861.
The objective of this study was to determine the occurrence and antimicrobial profile of AmpC β-lactamase producing bacteria.
The study was conducted at The Children's Hospital and The Institute of Child Health Lahore, Pakistan, during September 2011 to June 2012. A total number of 1,914 blood samples of suspected neonatal septicemia were processed. Isolates were identified using Gram's staining, API 20E and API 20NE tests. Gram negative isolates were screened for AmpC β-lactamase production against ceftazidime, cefotaxime and cefoxitin resistance and confirmed by inhibitor based method.
Total number of 54 (8.49%) Gram positive and 582 (91.5%) Gram negative bacteria were identified. Among Gram negative isolates 141 (22%) were AmpC producers and found to be 100% resistant to co-amoxiclav, cefoxitin, ceftazidime, cefotaxime, cefuroxime, cefixime, ceftriaxone, cefpodoxime, gentamicin, amikacin and aztreonam. Less resistance was observed against cefepime (30.4%), sulbactam-cefoperazone (24.8%), piperacillin-tazobactam (10.6%), ciprofloxacin (20.5%) and meropenem (2.1%). All the isolates were found sensitive to imipenem. The patients harbored AmpC β-lactamases were on various interventions in which intravenous line was noted among (51.1%), naso-gastric tube (37.6%), ambu bag (8.5%), endotracheal tube (3.5%), ventilator (2.1%) and surgery (0.7%).
Extensive use of invasive procedures and third generation cephalosporins should be restricted to avoid the emergence of AmpC beta-lactamases in neonates.
本研究的目的是确定产AmpCβ-内酰胺酶细菌的发生率及抗菌谱。
该研究于2011年9月至2012年6月在巴基斯坦拉合尔儿童医院及儿童健康研究所进行。共处理了1914份疑似新生儿败血症的血样。使用革兰氏染色、API 20E和API 20NE试验鉴定分离株。对革兰氏阴性分离株进行AmpCβ-内酰胺酶产生情况的筛查，检测其对头孢他啶、头孢噻肟和头孢西丁的耐药性，并通过基于抑制剂的方法进行确认。
共鉴定出54株（8.49%）革兰氏阳性菌和582株（91.5%）革兰氏阴性菌。在革兰氏阴性分离株中，141株（22%）为AmpC产生菌，发现它们对阿莫西林克拉维酸、头孢西丁、头孢他啶、头孢噻肟、头孢呋辛、头孢克肟、头孢曲松、头孢泊肟、庆大霉素、阿米卡星和氨曲南100%耐药。对头孢吡肟（30.4%）、舒巴坦-头孢哌酮（24.8%）、哌拉西林-他唑巴坦（10.6%）、环丙沙星（20.5%）和美罗培南（2.1%）的耐药性较低。所有分离株对亚胺培南均敏感。携带AmpCβ-内酰胺酶的患者接受了各种干预措施，其中使用静脉输液管的占（51.1%），鼻胃管的占（37.6%），复苏面罩的占（8.5%），气管内插管的占（3.5%），呼吸机的占（2.1%），手术的占（0.7%）。
应限制侵入性操作和第三代头孢菌素的广泛使用，以避免新生儿中出现AmpCβ-内酰胺酶。
