Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt.
Department of Microbiology, Faculty of Science, Zagazig University, Zagazig, Egypt.
J Appl Microbiol. 2022 Jun;132(6):4555-4568. doi: 10.1111/jam.15563. Epub 2022 Apr 13.
The aim of this study was to investigate the frequency, molecular characterization, virulence genes, resistance genes and antimicrobial profile of nosocomial extended spectrum beta lactamase producing Klebsiella species. A total of 22 (12.2%) K. pneumoniae strains were isolated from 180 clinical samples collected from hospitalized patients in Egypt. K. pneumoniae biotypes were B1 (72.8%), B3 (13.6%) and B4 (13.6%). The isolates were classified for the capsular serotypes, 86.4% (20/22) were of K1 serotype, while only two isolates (13.64%) were of K2 serotype. Hypermucoviscous K. pneumoniae isolates accounted for 68.2%. Biofilm formation ability of K. pneumoniae was determined by microtitre plate method. The majority of the isolates (40.9%) were moderate biofilm producers, while 27.3% were strong biofilm producers. All K. pneumoniae strains were positive for fimH and traT genes, while magA was identified in only 63.6% of the isolates. The antibiotic susceptibility profile of the isolates (n = 22) was determined by the disc diffusion technique using 23 different antibiotics. Streptomycin and imipenem are the most effective antibiotics against 22 tested K. pneumoniae isolates with sensitivity rates of 63.64% and 54.54% respectively. All tested K. pneumoniae isolates showed high resistance to amoxicillin∕clavulanate (100%), cefuroxime (100%) and ceftazidime (95.45%). Extended spectrum beta lactamases (ESBL) production and the presence of ESBL-related genes were tested in the isolates. All the isolates tested positive for blaVIM, NDM1 and blaTEM, while only 81.8 %tested positive for the blaSHV gene. Increasing antimicrobial resistance in K. pneumoniae causing nosocomial infections limits the use of antimicrobial agents for treatment. Furthermore, the spread of biofilm, multiple drug resistant and ESBL-producing K. pneumoniae isolates is a public threat for hospitalized patients.
本研究旨在调查产超广谱β-内酰胺酶（ESBL）的医院获得性肺炎克雷伯菌的频率、分子特征、毒力基因、耐药基因和抗菌谱。从埃及住院患者采集的 180 份临床样本中分离出 22 株（12.2%）肺炎克雷伯菌。肺炎克雷伯菌生物型为 B1（72.8%）、B3（13.6%）和 B4（13.6%）。对分离株进行荚膜血清型分类，86.4%（20/22）为 K1 血清型，仅有两株（13.64%）为 K2 血清型。高黏液性肺炎克雷伯菌分离株占 68.2%。通过微量滴定板法测定肺炎克雷伯菌的生物膜形成能力。大多数分离株（40.9%）为中度生物膜产生菌，27.3%为强生物膜产生菌。所有肺炎克雷伯菌均为 fimH 和 traT 基因阳性，而 magA 仅在 63.6%的分离株中检出。采用 23 种不同抗生素的纸片扩散法测定分离株（n=22）的抗生素敏感性谱。链霉素和亚胺培南是对 22 株测试肺炎克雷伯菌最有效的抗生素，敏感性率分别为 63.64%和 54.54%。所有测试的肺炎克雷伯菌分离株对阿莫西林/克拉维酸（100%）、头孢呋辛（100%）和头孢他啶（95.45%）表现出高度耐药性。检测分离株产超广谱β-内酰胺酶（ESBL）和 ESBL 相关基因的存在。所有分离株均blaVIM、NDM1 和 blaTEM 基因阳性，而 blaSHV 基因仅 81.8%阳性。导致医院获得性感染的肺炎克雷伯菌对抗菌药物的耐药性不断增加，限制了抗菌药物的使用。此外，生物膜、多药耐药和产 ESBL 肺炎克雷伯菌分离株的传播对住院患者构成公共威胁。
