Liew Siew Mun, Rajasekaram Ganeswrei, Puthucheary Sd Ampalam, Chua Kek Heng
Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Department of Pathology, Hospital Sultanah Aminah, Johor Bahru, Johor, Malaysia.
PeerJ. 2019 Jan 22;7:e6217. doi: 10.7717/peerj.6217. eCollection 2019.
is ubiquitous, has intrinsic antibiotic resistance mechanisms, and is associated with serious hospital-associated infections. It has evolved from being a burn wound infection into a major nosocomial threat. In this study, we compared and correlated the antimicrobial resistance, virulence traits and clonal relatedness between clinical and fresh water environmental isolates of .
219 isolates were studied: (a) 105 clinical isolates from 1977 to 1985 ( = 52) and 2015 ( = 53), and (b) 114 environmental isolates from different fresh water sources. All isolates were subjected to ERIC-PCR typing, antimicrobial susceptibility testing and virulence factor genes screening.
Clinical and environmental isolates of were genetically heterogenous, with only four clinical isolates showing 100% identical ERIC-PCR patterns to seven environmental isolates. Most of the clinical and environmental isolates were sensitive to almost all of the antipseudomonal drugs, except for ticarcillin/clavulanic acid. Increased resistant isolates was seen in 2015 compared to that of the archived isolates; four MDR strains were detected and all were retrieved in 2015. All clinical isolates retrieved from 1977 to 1985 were susceptible to ceftazidime and ciprofloxacin; but in comparison, the clinical isolates recovered in 2015 exhibited 9.4% resistance to ceftazidime and 5.7% to ciprofloxacin; a rise in resistance to imipenem (3.8% to 7.5%), piperacillin (9.6% to 11.3%) and amikacin (1.9% to 5.7%) and a slight drop in resistance rates to piperacillin/tazobactam (7.7% to 7.5%), ticarcillin/clavulanic acid (19.2% to 18.9%), meropenem (15.4% to 7.5%), doripenem (11.5% to 7.5%), gentamicin (7.7% to 7.5%) and netilmicin (7.7% to 7.5%). Environmental isolates were resistant to piperacillin/tazobactam (1.8%), ciprofloxacin (1.8%), piperacillin (4.4%) and carbapenems (doripenem 11.4%, meropenem 8.8% and imipenem 2.6%). Both clinical and environmental isolates showed high prevalence of virulence factor genes, but none were detected in 10 (9.5%) clinical and 18 (15.8%) environmental isolates. The gene was not detected in any of the clinical isolates. Resistance to carbapenems (meropenem, doripenem and imipenem), β-lactamase inhibitors (ticarcillin/clavulanic acid and piperacillin/tazobactam), piperacillin, ceftazidime and ciprofloxacin was observed in some of the isolates without virulence factor genes. Five virulence-negative isolates were susceptible to all of the antimicrobials. Only one MDR strain harbored none of the virulence factor genes.
Over a period of 30 years, a rise in antipseudomonal drug resistance particularly to ceftazidime and ciprofloxacin was observed in two hospitals in Malaysia. The occurrence of resistant environmental isolates from densely populated areas is relevant and gives rise to collective anxiety to the community at large
[细菌名称]广泛存在，具有内在的抗生素耐药机制，且与严重的医院感染相关。它已从烧伤创面感染演变成主要的医院内威胁。在本研究中，我们比较并关联了[细菌名称]临床分离株和淡水环境分离株之间的抗菌药物耐药性、毒力特征及克隆相关性。
对219株[细菌名称]分离株进行了研究：(a) 1977年至1985年（n = 52）及2015年（n = 53）的105株临床分离株，以及(b) 来自不同淡水水源的114株环境分离株。所有分离株均进行ERIC-PCR分型、抗菌药物敏感性测试及毒力因子基因筛查。
[细菌名称]的临床和环境分离株在基因上具有异质性，仅有4株临床分离株与7株环境分离株呈现100%相同的ERIC-PCR图谱。大多数临床和环境分离株对几乎所有抗假单胞菌药物敏感，除替卡西林/克拉维酸外。与存档分离株相比，2015年耐药分离株有所增加；检测到4株多重耐药菌株，均于2015年获得。1977年至1985年获得的所有临床分离株对头孢他啶和环丙沙星敏感；但相比之下，2015年获得的临床分离株对头孢他啶的耐药率为9.4%，对环丙沙星的耐药率为5.7%；对亚胺培南（从3.8%升至7.5%）、哌拉西林（从9.6%升至11.3%）和阿米卡星（从1.9%升至5.7%）的耐药性有所上升，对哌拉西林/他唑巴坦（从7.7%降至7.5%）、替卡西林/克拉维酸（从19.2%降至18.9%）、美罗培南（从15.4%降至7.5%）、多利培南（从11.5%降至7.5%）、庆大霉素（从7.7%降至7.5%）和奈替米星（从7.7%降至7.5%）的耐药率略有下降。环境分离株对哌拉西林/他唑巴坦（1.8%）、环丙沙星（1.8%）、哌拉西林（4.4%）和碳青霉烯类药物（多利培南11.4%、美罗培南8.8%、亚胺培南2.6%）耐药。临床和环境分离株均显示毒力因子基因的高流行率，但在10株（9.5%）临床分离株和18株（15.8%）环境分离株中未检测到毒力因子基因。在任何临床分离株中均未检测到[特定基因名称]基因。在一些无毒力因子基因的分离株中观察到对碳青霉烯类药物（美罗培南、多利培南和亚胺培南）、β-内酰胺酶抑制剂（替卡西林/克拉维酸和哌拉西林/他唑巴坦）、哌拉西林、头孢他啶和环丙沙星的耐药性。5株无毒力分离株对所有抗菌药物敏感。仅1株多重耐药菌株未携带任何毒力因子基因。
在30年期间，马来西亚两家医院中对抗假单胞菌药物尤其是对头孢他啶和环丙沙星的耐药性有所上升。来自人口密集地区的耐药环境分离株的出现具有相关性，并引起了整个社区的集体焦虑。
