Mataj Valbona, Guney Mustafa, Sig Ali Korhan, Uskudar-Guclu Aylin, Albay Ali, Bedir Orhan, Baysallar Mehmet
Clin Lab. 2020 Aug 1;66(8). doi: 10.7754/Clin.Lab.2020.191033.
Bloodstream infections are one of the major causes of healthcare-associated morbidity and mortality. The present study aims to investigate the prevalence of the microorganisms isolated from blood cultures and to evaluate susceptibilities to antimicrobial agents in a tertiary center, Gulhane Training and Research Hospital, Ankara, Turkey.
Blood cultures (BCs) were incubated in BACTEC/9050 (Becton Dickinson, USA) (2007 - 2015) and BacT/ALERT (bio-Merieux, France) (2014 - 2016) automated systems. PhoenixTM 100 system (Becton Dickinson, USA) (2007 - 2014), MALDI-TOF MS (Bruker, USA) (2015 - 2016) and conventional techniques were used for the identification of isolated microorganisms. According to CLSI (2007 - 2014) and EUCAST (2015 - 2016) criteria, Kirby-Bauer disc diffusion method, PhoenixTM system, and broth microdilution were applied for antimicrobial susceptibility testing. Two five-year periods were statistically compared regarding antibiotic resistance.
From the overall evaluated 31,380 BCs, 7,367 cultures (23.5%) were positive, excluding 503 BCs (6.4%), which were interpreted as contamination. Of 7,367 isolated microorganisms, 3,680 (50.0%) were gram-negative, 3,303 (44.8%) were gram-positive bacteria, and 384 (5.2%) were fungi. Coagulase-negative staphylococci (CoNS) were predominantly isolated (n = 2,075; 28.2%) among gram-positives. E.coli (n = 978; 13.3%) was the most frequently isolated gram-negative species. Between the first and the last five-year period, three genera (Enterococcus spp., Acinetobacter spp., Streptococcus spp.) showed significant differences when isolated, and only Enterococcus spp. showed increased isolation rates. In total, 90.3% of CoNS and 32% of S. aureus were methicillin-resistant. Only 75 strains of Enterococcus spp. (12.1%) were vancomycin-resistant. ESBL was detected in 40.6% of E. coli and 30.7% of Klebsiella spp. isolates. Carbapenem resistance showed a significant increase, particularly in K. pneumoniae (> 20%).
The findings suggest that there was a threatening condition in antimicrobial resistance rates, especially for some antimicrobials between two periods. Although antimicrobial resistance is usually associated with MRSA, carbapenem resistance, ESBL, and VRE, the problem is far beyond these definitions, consisting of not just medicine, but also commercial companies, food industry, veterinarians, and other areas.
血流感染是医疗相关发病和死亡的主要原因之一。本研究旨在调查从血培养中分离出的微生物的流行情况，并评估土耳其安卡拉古尔汗培训与研究医院这一三级中心中分离出的微生物对抗菌药物的敏感性。
血培养（BCs）在BACTEC/9050（美国BD公司）（2007 - 2015年）和BacT/ALERT（法国生物梅里埃公司）（2014 - 2016年）自动化系统中进行培养。使用PhoenixTM 100系统（美国BD公司）（2007 - 2014年）、基质辅助激光解析电离飞行时间质谱（MALDI-TOF MS，美国布鲁克公司）（2015 - 2016年）和传统技术对分离出的微生物进行鉴定。根据临床和实验室标准协会（CLSI）（2007 - 2014年）和欧洲抗菌药物敏感性试验委员会（EUCAST）（2015 - 2016年）的标准，采用 Kirby-Bauer纸片扩散法、PhoenixTM系统和肉汤微量稀释法进行抗菌药物敏感性试验。对两个五年期的抗生素耐药性进行统计学比较。
在总共评估的31380份血培养中，7367份培养物（23.5%）呈阳性，排除503份（6.4%）被判定为污染的血培养。在7367株分离出的微生物中，3680株（50.0%）为革兰氏阴性菌，3303株（44.8%）为革兰氏阳性菌，384株（5.2%）为真菌。凝固酶阴性葡萄球菌（CoNS）在革兰氏阳性菌中分离得最为多见（n = 2075；28.2%）。大肠埃希菌（n = 978；13.3%）是最常分离出的革兰氏阴性菌。在第一个和最后一个五年期之间，三个菌属（肠球菌属、不动杆菌属、链球菌属）在分离时显示出显著差异，只有肠球菌属的分离率有所增加。总体而言，90.3%的CoNS和32%的金黄色葡萄球菌对甲氧西林耐药。只有75株肠球菌属菌株（12.1%）对万古霉素耐药。在40.6%的大肠埃希菌和30.7%的克雷伯菌属分离株中检测到超广谱β-内酰胺酶（ESBL）。碳青霉烯类耐药性显著增加，尤其是肺炎克雷伯菌（> 20%）。
研究结果表明，抗菌药物耐药率存在令人担忧的情况，特别是两个时期之间某些抗菌药物的耐药率。虽然抗菌药物耐药性通常与耐甲氧西林金黄色葡萄球菌（MRSA）、碳青霉烯类耐药、ESBL和耐万古霉素肠球菌（VRE）有关，但问题远不止这些定义，它不仅涉及医学领域，还包括商业公司、食品行业、兽医及其他领域。
