rome and Escherichia-coli-Infections

Quinolone and β-lactam resistance mechanisms and clonal relationships were characterized among Escherichia coli isolates resistant to ciprofloxacin and extended-spectrum cephalosporins associated with human extra-intestinal infections in Rome. The E. coli. ST131 clone was found to be prevalent. This clone invariably carried a specific pattern of substitutions in the topoisomerase genes and all isolates but one produced CTX-M-15. One ST131 isolate produced SHV-12. The new ST131 variant described here is of particular concern because it combines fluoroquinolone resistance and chromosomally encoded CTX-M-15.

Topics: Amino Acid Substitution; Anti-Bacterial Agents; Bacterial Typing Techniques; beta-Lactamases; Ciprofloxacin; Cluster Analysis; DNA Topoisomerase IV; Drug Resistance, Multiple, Bacterial; Escherichia coli; Escherichia coli Infections; Humans; Microbial Sensitivity Tests; Molecular Epidemiology; Molecular Typing; Mutation, Missense; Rome

Escherichia coli strains producing extended-spectrum beta-lactamases (ESBLs) are a major problem in many different hospitals worldwide, causing outbreaks as well as sporadic infections. The prevalence of Escherichia coli ESBL producers was analyzed in a surveillance study performed on the population attending the Policlinico Umberto I, the largest university hospital in Rome, Italy. We also investigated genotypes, pathogenicity islands, and plasmids in the ESBL-positive E. coli isolates as further markers that are useful in describing the epidemiology of the infections. In this survey, 163 nonreplicate isolates of Escherichia coli were isolated from patients from 86 different wards, and 28 were confirmed as ESBL producers. A high prevalence (26/28) of CTX-M-15 producers was observed within the bacterial population circulating in this hospital, and the dissemination of this genetic trait was associated with the spread of related strains; however, these do not have the characteristics of a single epidemic clone spreading. The dissemination was also linked to horizontal transfer among the prevalent E. coli genotypes of multireplicon plasmids showing FIA, FIB, and FII replicons in various combinations, which are well adapted to the E. coli species. The analysis of related bacteria suggests a probable interpatient transmission occurring in several wards, causing small outbreaks.

Topics: Anti-Bacterial Agents; beta-Lactamases; Cluster Analysis; Cross Infection; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Gene Transfer, Horizontal; Genomic Islands; Genotype; Hospitals, University; Humans; Microbial Sensitivity Tests; Molecular Epidemiology; Plasmids; Rome

A study on the prevalence of the faecal carriage of Escherichia coli O157 in lambs was performed in the major slaughterhouse in Rome, central Italy, during 2002. A total of 643 animals, consisting of 378 weaned and 265 suckling lambs, were assayed for the presence of E. coli O157. Five O157-agglutinating E. coli strains were isolated (0.8%, 95% CI 0.3-1.9). Only one was positive to PCR specific for the eae gene and produced verocytotoxin VT2, with a VTEC O157 overall prevalence of 0.2% (95% CI 0.0-1.0), whereas one strain possessed the eae gene only. All the other isolates were negative for the presence of all the virulence genes considered. The animals were either from local farms or imported from Eastern Europe. The results suggest an age-specific difference since the microorganism was isolated only from 0.3% (95% CI 0.0-1.7) of weaned lambs, while all samples from suckling lambs tested negative. From this study, the overall risk of human exposure to pathogenic E. coli O157 from lamb meat consumption derived from the major slaughterhouse in Rome can be considered reasonably low, particularly when suckling lamb meat is considered.

Topics: Abattoirs; Age Factors; Animals; Animals, Newborn; Escherichia coli Infections; Escherichia coli O157; Feces; Food Contamination; Humans; Meat; Prevalence; Risk Factors; Rome; Sheep Diseases

We report expanded-spectrum cephalosporin resistance in Escherichia coli from dogs and cats in Rome, Italy. Three major beta-lactamases (CMY-2, SHV-12, and CTX-M-1) are reported for the first time in E. coli from sick and healthy dogs and cats. Molecular characterization suggests the presence of several combinations of beta-lactamase genes in E. coli from companion animals.

Topics: Animals; beta-Lactamases; Cat Diseases; Cats; Cephalosporin Resistance; Dog Diseases; Dogs; Escherichia coli; Escherichia coli Infections; Microbial Sensitivity Tests; Reverse Transcriptase Polymerase Chain Reaction; Rome

Escherichia coli strains producing a variant of Shiga toxin 2 (Stx2), designated Stx2f, have been recently described in the stools of feral pigeons. During 1997-1998, 649 pigeons were trapped and examined in three different squares of Rome. Stool samples were collected from each bird and enrichment cultures were examined for the presence of Stx by the vero cell assay. Stx-producing E. coli (STEC) were isolated from the positive cultures and characterized by serotyping and PCR analysis of stx and other virulence-related genes. Stx was detected in 10.8% of the stool enrichment cultures. The percentage of positive birds did not differ significantly for the three flocks considered and the season of sample collection. Conversely, STEC carriage was significantly more frequent in young than in adult birds (17.9 versus 8.2%). None of the birds examined showed signs of disease. STEC strains were isolated from 30 of 42 Stx-positive cultures examined. All the strains produced Stx2f, and most of them possessed genes encoding for intimin and the cytolethal distending toxin (CLDT). Six serogroups were identified, but most of the isolates belonged to O45, O18ab, and O75. Molecular typing indicated that most of the isolates within a flock were clonally-related. This work confirms that pigeons represent a natural reservoir of STEC strains characterized by the production of the toxin variant Stx2f, and by the frequent presence of eae and cldt genes. Further work is needed to clarify whether these STEC may represent a cause of avian disease or even a potential health hazard for humans.

Topics: Animals; Animals, Wild; Bird Diseases; Chlorocebus aethiops; Columbidae; Disease Reservoirs; DNA Fingerprinting; Escherichia coli; Escherichia coli Infections; Feces; Polymerase Chain Reaction; Prevalence; Rome; Serotyping; Shiga Toxins; Vero Cells; Virulence

The results of a study on the incidence of nosocomial infections in a 1800 bed University hospital are reported. The study, carried out over a 9 months period, included: continuous microbiological surveillance, and a clinical and epidemiological survey. On the basis of the microbiological data collected and analyzed by a computer data system, developed and employed for the control of nosocomial infections, a weekly bed-to-bed survey was carried out by the staff of the Institute of Infectious Diseases. Among 2777 suspected nosocomial infections, as revealed by microbiological monitoring, 701 were confirmed after the bed-to-bed survey. The nosocomial infection rate was 6.75 per 100 discharges. It was higher in the surgical than in the medical wards (7.3 and 6 per 100 discharges, respectively). Nosocomial urinary tract infections were the most frequent (74.2%). The urinary infection rate was higher in the surgical than in the medical wards (5.3 and 4.6 per 100 discharges, respectively). Escherichia coli (19.4%), Pseudomonas aeruginosa (19.3%), Proteus spp. (18.4%) were the pathogens most frequently associated with nosocomial infections. They were followed by Klebsiella pneumoniae (7.8%) and Staphylococcus aureus (6.5%) in frequency. Among the risk factors, involved in nosocomial infections, the importance of catheterization was confirmed: among our patients with nosocomial urinary tract infections, 73.4% and 79.5%--in the medical and surgical wards, respectively--underwent urological instrumentation, mainly catheterization. An analogous and more detailed study is now in progress and will be extended in the next years.

Topics: Aged; Computers; Cross Infection; Data Collection; Escherichia coli Infections; Hospital Units; Hospitals, Teaching; Hospitals, University; Humans; Proteus Infections; Pseudomonas Infections; Rome; Urinary Catheterization; Urinary Tract Infections