In vitro antibacterial effect of probiotics against Carbapenamase-producing multidrug-resistant Klebsiella pneumoniae clinical isolates, Cairo, Egypt.

BACKGROUND: Searching for a non-antibiotic therapeutic option such as probiotics is gaining momentum nowadays. We aimed to evaluate the in vitro antibacterial ability of cell-free supernatant (CFS) of selected Lactobacillus strains (with probiotic properties) against clinical isolates of OXA-48-producing multidrug-resistant (MDR) Klebsiella pneumoniae separately and in combination with cefoperazone antibiotic. METHODS: Over a period of 8 months, a cross-sectional experimental study involving 590 Klebsiella pneumoniae isolates was done. Our study took place at The Specialized Pediatric Teaching Hospital of Cairo University. Of the 590 Klebsiella pneumoniae isolates collected from blood cultures, pus, endotracheal aspirates, and pleural fluid, only 50 unrepeated clinical isolates of MDR Klebsiella pneumoniae-producing OXA-48-like detected by CHROMID® OXA-48 (bioMérieux, France) were selected for our study. After determining the minimal inhibitory concentration of CFS of ten Lactobacillus strains and cefoperazone each, the synergistic effect of both was tested. RESULTS: Among ten tested Lactobacillus spp., a significant increase in the mean value of inhibition zone diameter with CFS of L. helveticus (14.32 mm) and L. rhamnosus (13.3 mm) was detected separately. On the contrary, an antagonistic activity against all tested isolates was detected upon combination of Lactobacilli with cefoperazone (512 µg/ml). The mean value of inhibition zone diameter of L. helveticus CFS+ cefoperazone was (11.0 mm) and for L. rhamnosus CFS+ cefoperazone was (10.88 mm) (p value <0.001). CONCLUSION: The antimicrobial efficiency of using CFS of Lactobacillus species separately indicates that these therapies may be a substitute treatment strategy against MDR Klebsiella pneumoniae.

First reported nosocomial outbreak of Serratia marcescens harboring bla IMP-4 and bla VIM-2 in a neonatal intensive care unit in Cairo, Egypt.

INTRODUCTION: Serratia marcescens is a significant hospital-acquired pathogen, and many outbreaks of S. marcescens infection have been reported in neonates. We report a sudden breakout of S. marcescens harboring the bla IMP-4 and bla VIM-2 metallo-ß-lactamase (MBL) genes that occurred from March to August 2015 in the neonatal intensive care unit of Cairo University Hospital, Cairo, Egypt. METHODS: During the study period, 40 nonduplicate clinical isolates of S. marcescens were collected from blood culture samples. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify each isolate. Then, minimum inhibitory concentrations of different antibiotics were assessed by the Vitek 2 compact system. Screening of the MBL genes bla IMP, bla VIM, bla SIM-1, bla SPM-1, and bla GIM-1 as well as the carbapenemase genes KPC, NDM, OXA-48, SME-1, and SME-2 were evaluated. Pulsed field gel electrophoresis was preformed to detect the genetic relationship of the isolates. RESULTS: Analysis showed that 37.5% of the S. marcescens clinical isolates were resistant to meropenem (minimum inhibitory concentrations ≥ 2 µg/mL), and bla IMP-4 and bla VIM-2 were the most prevalent MBL genes (42.5% and 37.5%, respectively). None of the other investigated genes were observed. Pulsed field gel electrophoresis typing revealed two discrete clones; 33/40 (82.5%) were pulsotype A and 7/40 (17.5%) were pulsotype B. CONCLUSION: Here, we report for the first time the detection of MBL-producing S. marcescens isolates, particularly IMP-4 and VIM-2 recovered from inpatients with bacteremias from the intensive care unit at Cairo University Hospital.

Reduced susceptibility of Enterococcus spp. isolates from Cairo University Hospital to tigecycline: Highlight on the influence of proton pump inhibitors.

OBJECTIVES: The incidence of reduced susceptibility to tigecycline (TIG) is increasing. This study aimed to analyse the in vitro activity of TIG against Enterococcus spp. isolates recovered from hospitalised patients and to evaluate the effect of omeprazole on the in vitro antimicrobial activity of TIG against several enterococcal species. METHODS: A total of 67 Enterococcus clinical isolates were identified by MALDI-TOF/MS and multiplex PCR. Minimum inhibitory concentrations (MICs) of TIG alone and in combination with omeprazole (10, 30 and 60mg/L) were determined by broth microdilution. Antibiotic susceptibility to other antibiotics was determined by disk diffusion. The presence of van, tet(X) and tet(X1) genes was tested by multiplex PCR. RESULTS: Of the 67 Enterococcus isolates, 2 (3.0%) were resistant to TIG and 13 (19.4%) were intermediate-resistant according to EUCAST. The frequencies of resistance to norfloxacin (80.6%), doxycycline (80.6%), levofloxacin (74.6%) and ciprofloxacin (71.6%) were highest, whilst that of vancomycin (25.4%) was lowest. The vanA gene was detected in 11 Enterococcus isolates (8 Enterococcus faecalis, 3 Enterococcus faecium), vanB in 3 Enterococcus isolates (2 E. faecium, 1 E. faecalis) and vanC-2/3 in 3 Enterococcus casseliflavus. Nine isolates (13.4%) were positive for tet(X1). TIG resistance occurred both in patients receiving or not TIG and/or omeprazole. Omeprazole increased TIG MICs by 4-128-fold. CONCLUSIONS: The possibility of selection of TIG-non-susceptible Enterococcus in the gut may occur with long-term use of omeprazole. Omeprazole influenced TIG activity in a concentration-dependent manner. To our knowledge; this is the first report of TIG-non-susceptible Enterococcus spp. in Egypt.

The emergence of a novel sequence type of MDR Acinetobacter baumannii from the intensive care unit of an Egyptian tertiary care hospital.

BACKGROUND AND AIM OF WORK: Acinetobacter baumannii is known for nosocomial outbreaks worldwide. In this study, we aimed to investigate the antibiotic susceptibility patterns and the clonal relationship of A. baumannii isolates from the intensive care unit (ICU) of an Egyptian hospital. METHODS: In the present study, 50 clinical isolates of multidrug resistant (MDR)-A. baumannii were obtained from patients admitted into the ICU from June to December 2015. All isolates were analyzed for antimicrobial susceptibilities. Multiplex PCR was performed to detect genes encoding oxacillinase genes (bla OXA-51-like, bla OXA-23-like, bla OXA-24-like, and bla OXA-58-like). Multilocus sequence typing (MLST) based on the seven-gene scheme (gltA, gyrB, gdhB, recA, cpn60, gpi, rpoD) was used to examine these isolates. RESULTS: All A. baumannii clinical isolates showed the same resistance pattern, characterized by resistance to most common antibiotics including imipenem (MIC ≥ 8µ/mL), with the only exception being colistin. Most isolates were positive for bla OXA-51-like and bla OXA-23-like (100 and 96%, respectively); however, bla OXA-24-like and bla OXA-58-like were not detected. MLST analysis identified different sequence types (ST195, ST208, ST231, ST441, ST499, and ST723) and a new sequence type (ST13929) with other sporadic strains. CONCLUSIONS: MDR A. baumannii strains harboring bla OXA-23-like genes were widely circulating in this ICU. MLST was a powerful tool for identifying and epidemiologically typing our strains. Strict infection control measures must be implemented to contain the worldwide spread of MDR A. baumannii in ICUs.

Rapid identification of nosocomial Acinetobacter baumannii isolated from a surgical intensive care unit in Egypt.

BACKGROUND: The rapid and accurate identification of nosocomial clinical isolates is the first essential step in investigating nosocomial outbreaks. We aimed to evaluate the performance of MDR-CHROMagar Acinetobacter versus matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in rapid detection of nosocomial Acinetobacter baumannii isolated from patients admitted to the surgical intensive care unit (SICU) of Kasr Alainy- Cairo University. METHODS: Over a period of 9 months from January 2014 until September 2014, 234 samples were collected. All samples were directly cultured on MDR-CHROMagar Acinetobacter media. MALDI-TOF MS was used to identify all non-lactose fermenting colonies on conventional media. Confirmation of species identification was done by detecting the blaOXA-51 like gene by PCR. RESULTS: Statistical evaluation of MDR-CHROMagar Acinetobacter against blaOXA-51 like PCR as the reference method for identification of A baumannii showed a sensitivity of 100% (95% confidence interval [CI]: 93.36% to 100%), specificity 98.8% (95% confidence interval [CI]: 96.04% to 99.68%), positive predictive value 96.4% (95%CI: 86.61% to 99.37%), negative predictive value 100% (95% CI: 97.36% to 100%). The statistical evaluation of MALDI-TOF against blaOXA-51 PCR was 100% concordance. CONCLUSION: MALDI-TOF MS was more specific than CHROMagar in identifying Acinetobacter spp and allowed further identification of non-A Baumannii species such as A hemolyticus and A nosocomialis, which are less common Acinetobacter spp involved in hospital-acquired infections.