multi drug resistant gram negative bacteria causing urinary tract infections a review

Urinary tract infections (UTIs) are among the most frequent infectious diseases affecting humans, and represent an important public health problem with a substantial economic burden. Due to the hig..

Real-time PCR assay for detection of Staphylococcus aureus, Panton-Valentine Leucocidin and Methicillin Resistance directly from clinical samples

Rapid detection of Methicillin Resistant Staphylococcus aureus (MRSA) is an important concern for both treatment and implementation of infection control policies. The present study provides an \u2018in house\u2019 real-time PCR assay to detect directly nuc, pvl, and mecA genes. The assay is able to perform identification of MRSA, Methicillin-Sensitive S. aureus, Methicillin-Resistant Coagulase Negative Staphylococci and the Panton-Valentine leukocidin virulence gene from rectal and pharyngeal swab samples in a screening context. We found an analytical sensitivity of this current Triplex PCR assay of 514 CFU/mL. Analytical specificity was tested with different Gram-positive and Gram-negative species and yielded no false-positive PCR signal. The sensitivity and specificity of the Triplex Real Time PCR were both 100% for these targets when compared with the culture and conventional methods. This assay is readily adaptable for routine use in a microbiology laboratory, as it will enable the implementation of timely and properly guided therapy and infection control strategies

Intrinsic role of coagulase negative staphylococci norA-like efflux system in fluoroquinolones resistance

NorA is a Staphylococcus aureus multidrug transporter that exports structurally distinct compounds including fluoroquinolones. In this study norA-like genes of Staphylococcus epidermidis (norASEP) and Staphylococcus haemolyticus (norASHAE) were identified and sequenced. The nucleotide identity of norASEP and norASHAE with norA was 75.3 and 74.1%, respectively, and the amino acid identity 87.7 and 86%, respectively. Inactivation of norASEP increased the ciprofloxacin susceptibility of E. coli DH5\u3b1 carrying the pB SK 198 norASEP EZ cat norASEP plasmid

Etest® versus broth microdilution for ceftaroline MIC determination with Staphylococcus aureus: results from PREMIUM, a European multicentre study

Objectives: To compare the concordance of ceftaroline MIC values 24 by reference broth microdilution (BMD) and Etest (BioMérieux, France) for MSSA and MRSA isolates, respectively, in isolates from PREMIUM (D372SL00001), a European multi-centre study.  Methods: Ceftaroline MICs were determined by reference BMD and by Etest for 1,242 MSSA and MRSA from adult patients with community-acquired pneumonia or complicated skin and soft tissue infections collected between February and May 2012; tests were performed across six European laboratories. Selected isolates with ceftaroline resistance in broth (MIC >1 mg/L) were retested in three central laboratories to confirm their behaviour.  Results: Overall concordance between BMD and Etest was good, with >97% essential agreement and >95% categorical agreement. Nevertheless, 12 of the 26 MRSA isolates found resistant by BMD scored as susceptible by Etest, with MICs ≤1 mg/L, thus counting as very major errors, whereas only five of 380 MRSA found ceftaroline susceptible in BMD were mis-categorised as resistant by Etest. Twenty-one of the 26 isolates with MICs of 2 mg/L by BMD were then re-tested twice by each of three central laboratories: BMD MICs of 2 mg/L were consistently found for 19 of the 21 isolates. Among 147 Etest results for these 21 isolates (original plus six repeats per isolate) 112 were >1 mg/L.  Conclusions: BMD and Etest have good overall agreement for ceftaroline against Staphylococcus aureus; nevertheless, reliable Etest-based discrimination of the minority of ceftaroline-resistant (MIC 2 mg/L) MRSA is extremely challenging, requiring careful reading of strips, ideally with duplicate testing

Characterization of Escherichia coli strains resistant to carbapenems isolated from rectal swab in a multidrug-resistant strains screening programme

The aim of the study is to characterize 28 Escherichia coli carbapenem-resistant strains isolated from multi-resistant screening. All the strains were tested through CARBA NP test and PCR analysis for molecular characterization of carbapenemase. Plasmid characterization and phylogenetic study was performed. The molecular characterization revealed that 24 of 28 strains harbour carbapenemases. The most involved plasmids are FIA, FIB, FIIS and FrepB replicons that belong to the IncF group. The phylo-typing analysis revealed a greater presence of the B2 group. Carbapenem resistance in E. coli, should be constantly monitored to avoid the onset of new epidemic episodes

Antimicrobial susceptibility of anaerobic clinical isolates: A two-year surveillance

: A total of 866 anaerobic strains isolated from clinical samples were tested by E-TEST for antimicrobial susceptibility. The most frequent antimicrobial resistance among the isolated genera, both Gram-positive and Gram-negative, was observed for clindamycin, and therefore, it cannot be considered as an empirical treatment. The antimicrobial resistance to benzylpenicillin was predominant among the Gram-negative bacteria, in particular the Bacteroides spp. The resistance percentages to meropenem and metronidazole are still low. However, metronidazole showed a considerable resistance in Finegoldia magna isolates, alone or in combination with other antibiotics. These data provide novel and useful epidemiological information on infections promoted by anaerobic bacteria

Isolation from Blood Culture of a Leclercia adecarboxylata Strain Producing an SHV-12 Extended-Spectrum Beta-Lactamase

We report on the first isolation of an extended-spectrum beta-lactamase-producing Leclercia adecarboxylata strain from the bloodstream in a 58-year-old man with acute myeloid leukemia. The strain, resistant to ceftazidime, cefotaxime, and aztreonam, produces the SHV-12 β-lactamase, one of the most common variants found in Italian nosocomial isolates of Enterobacteriaceae