This study investigated the prevalence of diverse Ambler class β-lactamase-encoding genes in 40 carbapenem-insensitive Acinetobacter baumannii isolates collected from two hospitals in Egypt during the period January-March 2012. The resistance levels to different groups of antimicrobial agents were determined. PCR was used to detect the different Ambler class β-lactamases encoding the following genes: blaTEM, blaSHV, blaCTX-M, blaVEB, blaPER, blaGES, blaVIM, blaIMP, blaSIM, blaSPM, blaGIM, blaNDM, blaADC, blaOXA-23, blaOXA-24, blaOXA-51, and blaOXA-58. ISAba1 and int1 were detected by PCR. The isolates were 100% resistant to amoxicillin-clavulanate, aztreonam, cefepime, cefotaxime, and ceftazidime. Of the isolates, 5% were resistant to colistin, 45% to amikacin, 70% to imipenem, and 85% to ciprofloxacin. The blaADC- and blaOXA-51-like genes were detected in the entire collection. The prevalences of blaOXA-23, blaOXA-24, and blaOXA-58 were 50%, 7.5%, and 5%, respectively. However, the prevalences of blaTEM-, blaPER-, and blaGES-like genes were 87.5%, 55%, and 27.5%, respectively. SHV, CTX-M, VEB, KPC, and MBL encoding genes were not detected. The ISAba1 was found upstream to blaOXA-51, blaOXA-23, and blaADC in 85%, 80%, and 50%, respectively. Of note, 45% (18/40) of the isolates co-produced extended-spectrum β-lactamases (PER and GES) and carbapenemases (OXA-23 and OXA-58). The blaADC-, blaTEM-, blaPER-, blaOXA-23-, and blaGES-like genes were found to be the most prevalent types of β-lactamase-encoding gene in A. baumannii collected from Egypt. A high level of carbapenem resistance is mediated by blaOXA-23, blaOXA-24, and blaOXA-58 (minimum inhibitory concentration (MIC) 32 to >256μg/ml), and a low level of carbapenem resistance is mediated by blaGES (MIC 4-16μg/ml) and by up-regulation of ISAba1-OXA-51 (MIC 1-4μg/ml). Class B MBL was not identified to play a role in carbapenem resistance in A. baumannii isolates from Egypt.

Background: Escherichia coli (E. coli), the main human gut microorganism, is one of the evolved superbugs because of acquiring antimicrobial resistance (AMR) determinants via horizontal gene transfer (HGT). Purpose: This study aimed to screen isolates of gut commensal E. coli from healthy adult individuals for antimicrobial susceptibility and plasmid-mediated AMR encoding genes. Methods: Gut commensal E. coli bacteria were isolated from fecal samples that were taken from healthy adult individuals and investigated phenotypically for their antimicrobial susceptibility against diverse classes of antimicrobials using the Kirby Bauer disc method. PCR-based molecular assays were carried out to detect diverse plasmid-carried AMR encoding genes and virulence genes of different E. coli pathotypes (eaeA, stx, ipaH, est, elt, aggR and pCVD432). The examined AMR genes were β-lactam resistance encoding genes (bla_CTX-M1, bla_TEM, bla_CMY-2), tetracycline resistance encoding genes (tetA, tetB), sulfonamides resistance encoding genes (sul1, sulII), aminoglycoside resistance encoding genes (aac(3)-II, aac(6′)-Ib-cr) and quinolones resistance encoding genes (qnrA, qnrB, qnrS). Results: PCR results revealed the absence of pathotypes genes in 56 isolates that were considered gut commensal isolates. E. coli isolates showed high resistance rates against tested antimicrobial agents belonging to both β-lactams and sulfonamides (42/56, 75%) followed by quinolones (35/56, 62.5%), tetracyclines (31/56, 55.4%), while the lowest resistance rate was to aminoglycosides (24/56, 42.9%). Antimicrobial susceptibility profiles revealed that 64.3% of isolates were multidrug-resistant (MDR). High prevalence frequencies of plasmid-carried AMR genes were detected including bla_TEM (64%) sulI (60.7%), qnrA (51.8%), aac(3)-II (37.5%), and tetA (46.4%). All isolates harbored more than one gene with the most frequent genetic profile among isolates was bla_TEM-bla_CTX-M1-like-qnrA-qnrB-tetA-sulI. Conclusion: Results are significant in the evaluation of plasmid-carried AMR genes in the human gut commensal E. coli, suggesting a potential human health risk and the necessity of strict regulation of the use of antibiotics in Egypt. Commensal E. coli bacteria may constitute a potential reservoir of AMR genes that can be transferred to other bacterial species.

Introduction: Ventilator-associated pneumonia (VAP) is one of the common serious infectious diseases encountered in the intensive care unit (ICU), which highly affects the healthcare cost and patient prognosis. VAP is caused by various antimicrobial-resistant aetiological agents and the clinical manifestations lack sensitivity and specificity, making the prompt treatment is a challenge. This study aimed to investigate the microbial profile of VAP causing microorganisms among ICU patients in Egypt, antimicrobial susceptibility patterns and the genetic diversity among the frequently isolated organisms. Methodology: Throughout the period from August 2016 to August 2017, endotracheal aspirate (ETA) specimens were collected from ICU patients with clinically suspected VAP in two tertiary hospitals in Cairo. ETA specimens were investigated for the microbial content. The antimicrobial susceptibility was determined by the Kirby-Bauer method. ERIC-PCR was performed for genotyping. Results: Fifty microbiologically confirmed VAP cases were identified. The most frequently isolated microorganisms were Klebsiella spp., followed by Pseudomonas aeruginosa, Acinetobacter baumannii. Candida spp. was the most isolated fungi. A single isolate of each Cupriavidus pauculus and Aeromonas salmonicida was isolated. Antimicrobial susceptibility profiles indicated 40% of isolates were multidrug-resistant (MDR). ERIC-PCR revealed no genetic relatedness among K. pneumoniae isolates, the most frequently isolated microorganism. Conclusions: Gram-negative bacteria are the main causative agents of VAP cases, which mostly are MDR. Microorganisms like C. pauculus and A. salmonicida should be taken into consideration as VAP causative agents. There was no common source of infection suggesting likely endogenous sources of K. pneumoniae, the main causative agent of VAP in this study.

This study aimed at the characterization of carbapenem-resistant Klebsiella pneumoniae isolates focusing on typing of the bla_OXA-48-like genes. Additionally, the correlation between the resistance pattern and biofilm formation capacity of the carbapenem-resistant K. pneumoniae isolates was studied. The collected isolates were assessed for their antimicrobial resistance and carbapenemases production by a modified Hodge test and inhibitor-based tests. The carbapenemases encoding genes (bla_KPC, bla_NDM, bla_VIM, bla_IMP, and bla_OXA-48-like) were detected by PCR. Isolates harboring bla_OXA-48-like genes were genotyped by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) and plasmid profile analysis. The discriminatory power of the three typing methods (antibiogram, ERIC-PCR, and plasmid profile analysis) was compared by calculation of Simpson’s Diversity Index (SDI). The transferability of bla_OXA-48 gene was tested by chemical transformation. The biofilm formation capacity and the prevalence of the genes encoding the fimbrial adhesins (fimH-1 and mrkD) were investigated. The isolates showed remarkable resistance to β-lactams and non-β-lactams antimicrobials. The coexistence of the investigated carbapenemases encoding genes was prevalent except for only 15 isolates. The plasmid profile analysis had the highest discriminatory power (SDI = 0.98) in comparison with ERIC-PCR (SDI = 0.89) and antibiogram (SDI = 0.78). The transferability of bla_OXA-48 gene was unsuccessful. All isolates were biofilm formers with the absence of a significant correlation between the biofilm formation capacity and resistance profile. The genes fimH-1 and mrkD were prevalent among the isolates. The prevalence of carbapenemases encoding genes, especially bla_OXA-48-like genes in Egyptian healthcare settings, is worrisome and necessitates further strict dissemination control measures.