ABSTRACT
A one-year (1993) survey of the distribution of pathogens causing respiratory and urinary infections and their antimicrobial susceptibility was performed. The most common bacteria isolated from the lower respiratory tract of patients in a district general hospital were Pseudomonas aeruginosa (35.9%) and Staphylococcus aureus (21.4%). About half of the Pseudomonas strains revealed a resistance to imipenem and gentamicin, whereas almost all Staphylococcus strains were resistant to penicillin G. The most common isolates from urine of in and out-patients were Escherichia coli (32.3% and 39.8%) and Enterococcus faecalis (16.6% and 14.2%). Escherichia coli strains were largely susceptible to almost all chemoantibiotics tested, whereas Enterococcus faecalis demonstrated a high resistance pattern. Pseudomonas aeruginosa isolated from urine were more sensitive to chemoantibiotics than respiratory strains and the susceptibility of Staphylococcus aureus isolated from hospitalized or out-patients was different. A periodic monitoring system devised to give information about the circulation of bacteria and the chemoantibiotic resistance in a local context would be useful to assess the local trends and select drugs for therapy.
Subject(s)
Drug Resistance, Microbial , Respiratory Tract Infections/microbiology , Urinary Tract Infections/microbiology , Evaluation Studies as Topic , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacteria/pathogenicity , Gram-Positive Bacteria/isolation & purification , Gram-Positive Bacteria/pathogenicity , Health Surveys , Humans , Microbial Sensitivity Tests , Sputum/microbiology , Time Factors , Urine/microbiologyABSTRACT
Two groups of Escherichia coli were assayed to evaluate hydrophobic characters and the secretion of enzymes and cytotoxic factors. Group 1 included strains isolated from the urine of patients with lower urinary tract infection (UTI) and group 2 included strains from the same sample of asymptomatic subjects. The bacterial hydrophobicity was similar in the two groups and related to their adhesion to plastic surfaces, while both cytotoxic factors (demonstrated using a microscopic and a spectrophotometric technique) and hydrolysing enymes were secreted more by the first group of E. coli. The superior production of these factors may be important in the pathogenesis and in the development of symptomatic UTI infections.