First identification of an Escherichia coli clinical isolate producing both metalloβ-lactamase VIM-2 and extended-spectrum β-lactamase IBC-1

AbstractAn Escherichia coli strain with decreased susceptibility to carbapenems was isolated from a hospitalised patient in Athens, Greece. The strain was resistant to all β-lactams, including aztreonam, whereas the MIC of imipenem and meropenem was 0.5 mg/L. A positive EDTA-disk synergy test suggested the production of a metallo-β-lactamase. PCR experiments revealed the presence of the blaVIM-2, blaIBC-1 and blaTEM-1 genes. Resistance to β-lactams was not transferable by conjugation. This is the first report of a clinical isolate of E. coli producing VIM-2, and the first report of the coexistence of blaVIM-2 and blaIBC-1 in a single clinical isolate

Transferable plasmid mediating resistance to multiple antimicrobial agents in Klebsiella pneumoniae isolates in Greece

AbstractObjective To investigate the underlying resistance mechanisms in 10 Klebsiella pneumoniae isolates.Methods Ten K. pneumoniae strains according to distinct bacteriocin typing and REP-PCR, were examined for their plasmid content, their ability to transfer their resistance to aminoglycosides and third-generation cephalosporins, and their production of aminoglycoside-modifying enzymes and β-lactamases.Results Transfer of resistance to the above-mentioned antibiotics as well as to co-trimoxazole and tetracycline in Escherichia coli strain RC 85 at a frequency of 5–106 was achieved for all strains by conjugation. Similar strains harbor a self-transferable multiresistant plasmid (80 kb) with similar EcoRI and HindIII restriction patterns. This plasmid encodes an extended-spectrum β-lactamase which confers high-level resistance to third-generation cephalosporins and aztreonam. It produces SHV-5 β-lactamase, as demonstrated by isoelectric focusing and DNA sequencing. Aminoglycoside resistance was co-transferred, and AAC(6′)-I, mediating resistance to gentamicin, tobramycin, netilmicin and amikacin, and AAC(3)-I, mediating resistance to gentamicin and sisomycin, were encoded in all isolates and their transconjugants, while APH(3′)-I, mediating resistance to kanamycin and neomycin, was encoded in seven strains.Conclusions It appears that a multiresistant transferable plasmid encoding the SHV-5 β-lactamase, causing unusually high resistance to ceftazidime and aztreonam, and the combination AAC(6′)-I + AAC(3)-I of acetylating enzymes causing, also resistance to all clinically available aminoglycosides, is established in K. pneumoniae in Greece

Diversity in Acinetobacter baumannii isolates from paediatric cancer patients in Egypt

Acinetobacter baumannii is an important nosocomial pathogen, commonly causing infections in immunocompromised patients. It is increasingly reported as a multidrug-resistant organism, which is alarming because of its capability to resist all available classes of antibiotics including carbapenems. The aim of this study was to examine the genetic and epidemiological diversity of A. baumannii isolates from paediatric cancer patients in Egypt, by sequencing the intrinsic blaOXA -51-like gene, genotyping by pulsed-field gel electrophoresis and multi-locus sequence typing in addition to identifying the carbapenem-resistance mechanism. Results showed a large diversity within the isolates, with eight different blaOXA -51-like genes, seven novel sequence types and only 28% similarity by pulsed-field gel electrophoresis. All three acquired class-D carbapenemases (OXA-23, OXA-40 and OXA-58) were also identified among these strains correlating with resistance to carbapenems. In addition, we report the first identification of ISAba2 upstream of blaOXA -51-like contributing to high-level carbapenem resistance. This indicates the presence of several clones of A. baumannii in the hospitals and illustrates the large genetic and epidemiological diversity found in Egyptian strains

Ultrafast Structural Dynamics of BlsA, a Photoreceptor from the Pathogenic Bacterium Acinetobacter baumannii

Acinetobacter baumannii is an important human pathogen that can form biofilms and persist under harsh environmental conditions. Biofilm formation and virulence are modulated by blue light, which is thought to be regulated by a BLUF protein, BlsA. To understand the molecular mechanism of light sensing, we have used steady-state and ultrafast vibrational spectroscopy to compare the photoactivation mechanism of BlsA to the BLUF photosensor AppA from Rhodobacter sphaeroides. Although similar photocycles are observed, vibrational data together with homology modeling identify significant differences in the β5 strand in BlsA caused by photoactivation, which are proposed to be directly linked to downstream signaling

Procalcitonin (PCT) and C-reactive Protein (CRP) as severe systemic infection markers in febrile neutropenic adults

Abstract\ud \ud \ud \ud Background\ud \ud Procalcitonin (PCT) is an inflammatory marker that has been used as indicator of severe bacterial infection. We evaluated the concentrations of PCT as a marker for systemic infection compared to C-reactive protein (CRP) in patients neutropenic febrile.\ud \ud \ud \ud Methods\ud \ud 52 adult patients were enrolled in the study. Blood sample was collected in order to determine the serum concentrations of PCT, CRP and other hematological parameters at the onset of fever. The patients were divided into 2 groups, one with severe infection (n = 26) and the other in which the patients did not present such an infection (n = 26). Then PCT and CRP concentrations at the fever onset were compared between groups using non parametric statistical tests, ROC curve, sensitivity, specificity, likelihood ratio, and Spearman's correlation coefficient.\ud \ud \ud \ud Results\ud \ud The mean of PCT was significantly higher in the group with severe infection (6.7 ng/mL versus 0.6 ng/mL – p = 0.0075) comparing with CRP. Serum concentrations of 0.245 ng/mL of PCT displayed 100% de sensitivity and 69.2% specificity. PCT concentrations of 2,145 ng/mL presented a likelihood ratio of 13, which was not observed for any concentration of CRP.\ud \ud \ud \ud Conclusion\ud \ud PCT seems to be an useful marker for the diagnosis of systemic infection in febrile neutropenic patients, probably better than CRP

Management of KPC-Producing Klebsiella pneumoniae Infections

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) has become one of the most important contemporary pathogens, especially in endemic areas

Multiple lung abscesses due to acinetobacter infection: a case report

Acinetobacter species are well-known causes of nosocomial infections. Recent increasing evidence emphasize on the role of these pathogens in community-acquired infections

Immunomodulatory intervention in sepsis by multidrug-resistant Pseudomonas aeruginosa with thalidomide: an experimental study

BACKGROUND: Thalidomide is an inhibitor of tumour necrosis factor-alpha (TNFα) that has been proven effective for the treatment of experimental sepsis by Escherichia coli. It was tested whether it might behave as an effective immunomodulator in experimental sepsis by multidrug-resistant (MDR) Pseudomonas aeruginosa. METHODS: Sepsis was induced by the intraperitoneal injection of 1 × 10(8 )cfu/kg inoculum of the test isolate in a total of 109 Wistar rats divided in three groups as follows: group A controls; group B administered seed oil 30 minutes before bacterial challenge; and group C administered 50 mg/kg of thalidomide diluted in seed oil 30 minutes before bacterial challenge. Blood was sampled for estimation of endotoxins (LPS), TNFα, interferon-gamma (IFNγ), nitric oxide (NO) and malondialdehyde (MDA). LPS was measured by the QCL-1000 LAL assay, TNFα and IFNγ by ELISA, NO by a colorimetric assay and MDA by the thiobarbiturate assay. RESULTS: Mean (± SE) survival of groups A, B and C were 18.60 ± 1.84, 12.60 ± 0.60 and 30.50 ± 6.62 hours (p of comparisons A to C equal to 0.043 and B to C equal to 0.002). Decreased TNFα and NO levels were found in sera of animals of group C compared to group A. Plasma levels of LPS, MDA and IFNγ did not differ between groups. CONCLUSION: Intake of thalidomide considerably prolonged survival in experimental sepsis by MDR P.aeruginosa an effect probably attributed to decrease of serum TNFα

Molecular characterization of extended spectrum β -lactamases enterobacteriaceae causing lower urinary tract infection among pediatric population.

The β-lactam antibiotics have traditionally been the main treatment of Enterobacteriaceae infections, nonetheless, the emergence of species producing β- Lactamases has rendered this class of antibiotics largely ineffective. There are no published data on etiology of urinary tract infections (UTI) and antimicrobial resistance profile of uropathogens among children in Qatar. The aim of this study is to determine the phenotypic and genotypic profiles of antimicrobial resistant Enterobacteriaceae among children with UTI in Qatar. Bacteria were isolated from 727 urine positive cultures, collected from children with UTI between February and June 2017 at the Pediatric Emergency Center, Doha, Qatar. Isolated bacteria were tested for antibiotic susceptibility against sixteen clinically relevant antibiotics using phoenix and Double Disc Synergy Test (DDST) for confirmation of extended-spectrum beta-lactamase (ESBL) production. Existence of genes encoding ESBL production were identified using polymerase chain reaction (PCR). Statistical analysis was done using non-parametric Kappa statistics, Pearson chi-square test and Jacquard's coefficient. 201 (31.7%) of samples were confirmed as Extended Spectrum β -Lactamases (ESBL) Producing Enterobacteriaceae. The most dominant pathogen was 166 (83%) followed by 22 (11%). Resistance was mostly encoded by CTX-M (59%) genes, primarily CTX-MG1 (89.2%) followed by CTX-MG9 (7.7%). 37% of isolated bacteria were harboring multiple genes (2 genes or more). isolates were categorized into 11 clusters, while were grouped into five clonal clusters according to the presence and absence of seven genes namely TEM, SHV, CTX-MG1, CTX-MG2, CTX-MG8 CTX-MG9 CTX-MG25. Our data indicates an escalated problem of ESBL in pediatrics with UTI, which mandates implementation of regulatory programs to reduce the spread of ESBL producing Enterobacteriaceae in the community. The use of cephalosporins, aminoglycosides (gentamicin) and trimethoprim/sulfamethoxazole is compromised in Qatar among pediatric population with UTI, leaving carbapenems and amikacin as the therapeutic option for severe infections caused by ESBL producers

Management of KPC-Producing Klebsiella pneumoniae Infections

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) has become one of the most important contemporary pathogens, especially in endemic areas