Bacteriologia, virusologia, parazitologia, epidemiologia (Bucharest, Romania : 1990)最新文献

Indoor Air Quality: biological contaminants and health effects; airborne organisms and sampling instruments. Biological contaminants include bacteria, molds, viruses, animal dander and cat saliva, house dust, mites, cockroaches and pollen. Symptoms of health problems caused by biological pollutants include sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fevers. Children, elderly people with breathing problems, allergies and lung diseases are particularly susceptible to disease-causing biological agents in the indoor air. It is convenient to consider microbiological samplers for collecting organisms in air as falling into several broad categories. Many popular microbiological air samplers use the principle of impaction to trap the organisms by impacting them directly on to agar. Further distinct groups are the impingers, which operate by impinging organisms into liquid.

After isolation in 1970s, Campylobacter jejuni become the most commonly recognized cause of bacterial gastroenteritis in man. In animals is frequently found in bovines on ovines. Publishing of the genome sequence of Campylobacter jejuni 11168 (Parkhill, 2000) revealed the presence of only one cytochrome P450 in an operon involved in sugar and cell surface biosynthesis. The gene name is Cj1411c, is 1359 bp long and encodes 453 aa. The sequence is strictly conserved in Campylobacter jejuni RM221. Similarities with two cytochrome P450s, one form Silicobacter sp. and one form Poloromonas sp., were identified. These two enzymes are known to be involved in ascorbate and aldarate metabolism. The recombinant construct allowed the expression of active P450 enzyme with a 450 nm peak when binds CO. The protein was purified in proportion of approximately 70%. By deleting the P450 gene from the Campylobacter jejuni 11168 genome clear changes in cell morphology were identified cells becoming wider and shorter. The capsular sugar profile of the NCI strain reveals the presence of arabinose which was not found in the wild type strain.

The urinary tract infections (UTI) in children represent an important problem both because of their frequency, particularly in small children, and because of the morbidity they generate, sometimes on a long term. Escherichia coli represents the etiologic cause of 80% of these urinary infections. In 2005, 66 E. coli strains were analyzed and, in 2006, 69 E. coli strains were analyzed, coming from significantly positive urocultures > 10(5) UFC/ml. The E. coli strains were identified by the morphologic, culture and biochemical characters. The testing of the sensitivity to antibiotics was performed by the disk-diffusimetry method on Mueller-Hinton agar, and the reading was done visually, according to standards recommended by the suppliers of antibiotics disks. The results were as follows: Sensitivity to antibiotics, even though it was only tested for two years, has recorded slight decreases for some of the antibiotics (beta-lactams simple or in association with beta-lactamase inhibitors). This situation is probably due to a wrong treatment with these drugs, which made E. coli acquire the resistance characters. For cephalosporins, a decrease in the sensitivity was noticed above all for cephalosporins in generations 1 and 2, leaving those in generation 3 with an increased sensitivity. An important decrease was also recorded for the combination trimethoprim-sulfamethoxazole. Still, some urinary strains of E. coli remain sensitive to drugs such as: colistin, aminoglycosides, cephalosporins (particularly the third generation), fosfomycin, imipenem and the fluoroquinolones.

The emergence of carbapenem resistance in Gram-negative bacilli has become a global concern since these beta-lactams are often the only effective treatment left against many multiresistant strains. Metallo-beta-lactamase-producing isolates are now widespread worldwide, and especially in Europe where they have been responsible for rather large outbreaks. Our study proposes to investigate the presence of such isolates in Romania and to characterize them at the molecular level. A total of 28 clinical isolates clinical isolates of Pseudomonas aeruginosa and Acinetobacter baumannii were collected between 2003 and 2007 from 5 hospitals in 3 cities in north-east of Romania (Iaşi, Bacău, Galaţi). Antimicrobial susceptibility testing was performed according to CLSI guidelines. MBL detection was performed using the EPI phenotypic test and PCR, that was confirmed by hydrolysis test. The structure of MBL-encoding class 1 integron was determined by PCR mapping and sequencing. Genotyping was performed by RAPD. Only 2 strains showed a positive EPI test. PCR and sequencing revealed the presence of bla(VIM-2) and bla(IMP-13) genes, in strains 16GL Pa and 247Pa, respectively. RAPD showed clonal relatedness between the Pa247 and an Italian IMP-13 producing strain. Despite the infrequent occurrence of metallo-beta-lactamases in our settings, both VIM- and IMP-types are present in Romanian Pseudomonas aeruginosa clinical isolates.