ABSTRACT
The prevalence of methicillin-resistant Staphylococcus aureus nasal carriage among 959 healthy employees of the Hellenic Air Force was investigated from November 2004 to October 2005. Nine participants were found to be colonised by methicillin-resistant Staphylococcus aureus (MRSA) (SCCmec type IV). Eight of the MRSA isolates were PVL-negative and belonged to ST30 by MLST, while the remaining one isolate was PVL-positive and classified as ST-80.
Subject(s)
Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Military Personnel , Nasal Mucosa/microbiology , Staphylococcal Infections/epidemiology , Adolescent , Adult , Carrier State , Female , Greece/epidemiology , Humans , Male , Methicillin-Resistant Staphylococcus aureus/classification , Middle Aged , NoseSubject(s)
Cephalosporin Resistance , Klebsiella pneumoniae/drug effects , beta-Lactamases/analysis , Automation , Cephalosporins/pharmacology , False Negative Reactions , Humans , Klebsiella Infections/drug therapy , Klebsiella Infections/microbiology , Klebsiella pneumoniae/enzymology , Klebsiella pneumoniae/isolation & purification , Microbial Sensitivity Tests , Reproducibility of ResultsABSTRACT
Surveillance data on 12,944 bacterial isolates derived from nosocomial infections, reported to the Department of Microbiology and Infectious Diseases of the Hellenic Air Force and VA General Hospital over a 9-year period (1986-1994), were analyzed by the use of a microbial infection control software system. Overall, the isolation rate of Escherichia coli decreased from 25.2% in 1986 to 18.2% in 1994 and Proteus spp. from 5.3 to 2.6%. Remarkably, Pseudomonas spp. increased from 7.2 to 11.3%, Enterobacter spp. from 1.6 to 5.1%, Klebsiella spp. from 5.9 to 7.8% and Enterococcus spp. from 3 to 7.4%. Interestingly, the above phenomenon was paralleled by a significant increase in resistance rate to various antibiotics. Specifically, Staphylococcus aureus and coagulase-negative staphylococci, though they did not display any significant variation in isolation rates, showed an alarming increase in resistance rate to oxacillin, from 11 and 21% in 1986 to 51 and 75% in 1994, respectively. Enterococcus spp. sensitivity to vancomycin remained unlatered at 90%. The above-mentioned serious shift towards more resistant bacteria should be a matter of consideration.
Subject(s)
Bacteremia/microbiology , Cross Infection/microbiology , Enterobacteriaceae Infections/microbiology , Hospitals, Military , Klebsiella Infections/microbiology , Pseudomonas Infections/microbiology , Drug Resistance, Microbial , Greece , Hospital Bed Capacity, 300 to 499 , Humans , Microbial Sensitivity Tests , Respiratory Tract Infections/microbiology , Surgical Wound Infection/microbiology , Urinary Tract Infections/microbiologyABSTRACT
Plasmids encoding extended-spectrum beta-lactamases of the TEM, SHV, and AmpC families were introduced into common Escherichia coli and Klebsiella pneumoniae hosts to create a homogeneous panel for evaluating the abilities of five test systems to detect resistance to eight beta-lactam antibiotics. Although MICs, as determined by agar dilution or E test strips, were increased and disk diffusion zone diameters were diminished, breakpoints for resistance were often not reached, and neither approach was sensitive in detecting resistance to oxyimino-beta-lactams. The MicroScan 18-h microdilution or Vitek rapid automated procedures were similarly insensitive. Ceftazidime was the best single test antibiotic for detecting extended-spectrum beta-lactamase production. beta-Lactamases TEM-7 and TEM-12 were particularly difficult to detect. Because of such difficulties, the prevalence of extended-spectrum beta-lactamases is likely to be greater than is currently appreciated.
