Molecular characterization of bacteremic Escherichia coli isolates in Romania.

The increasing prevalence of invasive infections caused by antibiotic resistant Escherichia coli strains in Romanian patients, already mentioned in the European reports, requires better knowledge of their specific traits. Thus, a set of 38 E. coli blood isolates, collected between 2010 and 2012 at one of the local hospitals participating into the European Antimicrobial Resistance Surveillance Network, was investigated retrospectively with respect to the phylogenetic origin, extraintestinal virulence-associated markers (i.e. fimH, papC, papG alleles, sfa/foc, afa/dra, hly, cnf1, sat, iucC, fyuA, ibeA), and beta-lactamase encoding genes (i.e. bla CTX-M, bla TEM, and bla SHV alleles). The isolates with extended-spectrum beta-lactamase (ESBL) phenotypes were further characterized using PCR-based replicon typing and multilocus sequencing typing. For ST131 members, pulsed-field gel electrophoresis (PFGE) and PCR-based detection of fimH30 allele were performed. Overall, the isolates were more likely members of the major phylogenetic group A (53 %) and to a lesser extent of groups B2 (29 %), D (10 %), and B1 (8 %). All but three of the virulence markers sought (i.e. papGI, hly, cnf1) were detected with prevalence ranging from 3 % (i.e. ibeA, papGIII) to 87 % (fimH). As expected, the most complex genotypes (four to seven virulence markers) defined the isolates derived from phylogenetic groups B2 and D. ESBL producers were bla CTX-M-15-positive, mostly of phylogroup A (67 %), harboured IncF multireplicon plasmids, and belonged to six sequence types (i.e. ST10, ST131, ST167, ST410, ST540, ST1275). Members of ST10 clonal complex (i.e. ST10, ST167) were the most common. The ST131 isolates belonged to H30 subclone and displayed 74 % similarity at PFGE analysis.

Bloodstream infections in immunocompromised hosts.

Immunocompromised hosts are at high risk for bloodstream infections (BSIs); the outcome is unpredictable (even with adequate therapy), frequently severe (mortality 27%). A 26 months survey in a haematology/oncology hospital was set-up; it comprised 158 patients and detected 171 positive blood cultures. The origin of the infections was primitive in 27.22% and secondary in 72.78% of the cases; the most frequent cause was the presence of a vascular catheter (23.41%). The second most important cause were the respiratory infections (19.62%), followed by the urinary tract infections (UTIs) (11.39%). Gram negative bacilli represented 59.4%, the enterobacteriaceae were predominant (35.59%), followed by Pseudomonas aeruginosa (10.73%) and species like Serratia marcescens and Acinetobacter baumannii. Although isolated at low level, they worry by an increasing frequency. Among Gram positive cocci (43.51%) coagulase negative staphylococci (CoNS) were the most frequent (25.42%), followed by Staphylococcus aureus (18.08%); Enterococcus faecalis (5.65%) was isolated from polymicrobial (associated) infections. The strains of E. coli, K. pneumoniae and P. aeruginosa were constantly susceptible to carbapenems, demonstrating otherwise various susceptibility patterns, generally elevated to the antibiotics we tested. The production of extended spectrum betalactamase (ESBL) was 22.58%. The methicillin resistance was 54.4% in S. aureus strains; the susceptibility was variable among 7 other antibiotics tested. One Staphylococcus strain had reduced susceptibility to vancomycin. A multidisciplinary survey is necessary for the control of the multidrug resistant organisms (MDRO).

[Antibiotic resistance of bacterial strains isolated from bacteremias in immuno-compromised patients]. / Antibiorezistenta tulpinilor bacteriene izolate din bacteriemii la pacientii imunodeprimati.

UNLABELLED: Immunocompromised hosts are subjects of predilection to bloodstream infections. The global mortality is high. Bacterial strains are frequently multiresistant; fungemias are almost always deadly, in spite of the susceptibility of the fungus. OBJECTIVE: to evaluate the positive blood cultures in patients with malignant and non-malignant diseases and to determine the resistance mechanisms with the Vitek2. MATERIAL AND METHOD: a 29 months study--181 episodes of invasive infections--168 patients. The blood culture vials were Bactec Plus. The isolates were identified using Api galleries and with the Vitek 2. The susceptibility was tested by the disk-diffusion method (Oxoid Ltd.). Minimal inhibitory concentrations: Vitek2. INTERPRETATION: EUCAST 2008 standard. RESULTS: overall mortality: 27%. Gram-negative bacilli: 59.4% and 48.5% Gram-positive cocci. Klebsiella pneumoniae and Escherichia coli isolates accounted for 16.43% and 71.23%respectively; 25% of E. coli strains and 33% of K. pneumoniae respectively, produced extended-spectrum beta-lactamases. Oxacillin resistance: 54.4% of S. aureus isolates. No resistance to carbapenems in enterobacteria. CONCLUSIONS: Bacterial resistance is not likely to decrease, if at all; Death produced by infections is an event that can be prevented. Molecular determinations should be performed to assess the role of the virulence genes and of the resistance mechanisms and to help the better understanding of the interractions between bacteria and the human organism.

[Study of Streptococcus pneumoniae strains resistant to antibiotics analyzed at "Cantacuzino" NIRDMI during 2006-2008]. / Studiul tulpinilor de Streptococcus pneumoniae rezistente la antibiotice analizate la INCDMI "Cantacuzino" în perioada 2006-2008.

OBJECTIVE: The aim of the this study was the analysis of the resistance to antibiotics of Streptococcus pneumoniae isolated in last years. METHODS: 328 S. pneumoniae strains, coming from blood, CSF tracheal aspirate (TA), or sputum, pleural fluid (PL) and other samples (ear and sinus fluid) isolated in 2006-2008, were analyzed at INCDMI "Cantacuzino", National Reference Center for Streptococcus pneumoniae. Strains were tested for susceptibility to by agar diution method (minimal inhibitory concentration-MIC) to the following antibiotics: penicillin (Pc), erythromycin (Em), cephalothin (Kf). cefuroxim (Cxm), cefotaxim (Ctx), trimethoprim/sulfamethoxazol (Sxt), ofloxacin (Ojx), amoxicillin (Amx). tetracycline (Te), cloramphenicol (Cm), vancomycin (Va). RESULTS: The analysis of the results was done according to CLSI 2009. Pneumococci strains isolated from blood, CSF, TA or sputum and PL showed lower resistance level to antibiotics (38.8% Pc, 9.3% Cxm. 4.1% Ctx, 2.7% Amx. 24% Em, 2.4% Ofx, 68% Sxt) against those isolated from ear ans sinus fluid which revealed high levels of resistance (70% Pc, 11.2 % Cxm, 5.9 % Ctx, 3.4% Amx, 58.4 % Em. 3.8% Ofx, 73% Sxt). Strains resistant to penicillin, isolated from blood and CSF revealed the following aspects: 17% low level of resistance and 11 % high level of resistance. CONCLUSIONS. The most efficient antibiotics were Ctx, Amx and Oft. A continuous surveillance of pneumococci strains resistant to antibiotics is needed, as well as the use of an pneumococcal efficient vaccine.