avoparcin and Gram-Positive-Bacterial-Infections

The selective pressure resulting from the extensive use of antibiotics over the last 50 years has led to the emergence of bacterial resistance and to the dissemination of resistance genes among pathogenic microorganisms. Consequently, we are now at serious risk of suffering intractable, life-threatening infections. The progressive emergence and rapid dissemination of resistance to glycopeptides, the last resort for treating nosocomial infections with enterococci resistant to usual antibiotics, constitute one of the most dramatic examples of such resistance. Enterococci are normal human commensals, but are also a frequent cause of nosocomial urinary tract infections and nosocomial bacteremia. Enterococcus faecalis causes 80 to 90% of human enterococcal infections, while Enterococcus faecium accounts for most of the remainder. During the last decade, our understanding of the genetics and biochemical basis of resistance to glycopeptides has increased greatly. Furthermore, the application of molecular methods for the diagnosis of glycopeptide-resistant enterococci has provided new insights into the epidemiology of enterococcal infections.

Topics: Animals; Anti-Bacterial Agents; Cell Wall; Drug Resistance, Microbial; Drug Synergism; Drug Utilization; Enterococcus; Glycopeptides; Gram-Positive Bacteria; Gram-Positive Bacterial Infections; Humans; Operon; Peptidoglycan; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Teicoplanin; Vancomycin; Vancomycin Resistance

In this report we examined the glycopeptide susceptibility of enterococci, isolated in 2005, from slaughtered animals, within the confines of Hungarian Antibiotic Resistance Monitoring System. We determined the presence of the van genes as well as their genetic relatedness in enterococci from poultry. Enterococcus sp. strains (n=175) were collected from intestinal samples of slaughtered poultry in 2005. The origin of the samples was registered at county level. After screening the strains with 30 mg vancomycin disc 19 (86%) intermediate resistant and 4 (3%) fully resistant strains were found. The distribution of minimum inhibitory concentration (MIC)-values among 23 enterococcus strains which were intermediate or resistant to vancomycin were 0.25 mg/L (4.4%), 2 mg/L (8.6%), 4 mg/L (8.6%), 8 mg/L (61%), 16 mg/L (8.6%) and 256 mg/L (8.6%). The MICs of teicoplanin were 0.25 mg/L (4.3%), 1 (8.6%), 4 mg/L (78.3%), 16 mg/L (4.3%) and 256 mg/L (4.3%). The two most vancomycin-resistant strains were vanA carriers (1 E. faecalis and 1 E. faeciuum). The farms that produced these strains can be reservoirs of VRE and the affected farms should change the technology of disinfection and breeding in order to prevent the emergence of high numbers of human VRE isolates in Hungary.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Bacterial Proteins; Carbon-Oxygen Ligases; Enterococcus faecalis; Enterococcus faecium; Glycopeptides; Gram-Positive Bacterial Infections; Humans; Hungary; Intestines; Microbial Sensitivity Tests; Poultry; Vancomycin; Vancomycin Resistance

Prevalence of vancomycin-resistant enterococci (VRE) was investigated in Korean livestock 4 years after the ban of avoparcin in feed additives. VRE were isolated from approximately 16.7% of the chicken samples (57 strains from 342 meat samples) and 1.9% of the pig samples (4 from 214 fecal samples). No VRE, however, was isolated from 110 bovine fecal samples. All the 61 VRE isolates were vanA-type Enterococcus faecium expressing a high-level resistance to vancomycin, and showed resistance to teicoplanin as well except two poultry isolates. In addition, the VRE isolates had heterogeneous pulsed-field gel electrophoresis (PFGE) patterns of SmaI-digested DNA, although identical or closely related profiles were observed among strains isolated from the same farm. Although the chicken isolates were all poultry type with G at position 8,234 of the vanX gene, the pig isolates were all swine type with T at position 8,234 of the vanX gene.

Topics: Animal Feed; Animals; Animals, Domestic; Anti-Bacterial Agents; Bacterial Proteins; Cattle; Cattle Diseases; Chickens; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecium; Feces; Food Microbiology; Glycopeptides; Gram-Positive Bacterial Infections; Korea; Meat; Mutation; Poultry Diseases; Serine-Type D-Ala-D-Ala Carboxypeptidase; Swine; Swine Diseases; Vancomycin Resistance

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Denmark; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecium; Feces; Glycopeptides; Gram-Positive Bacterial Infections; Humans; Legislation, Drug; Swine; Vancomycin Resistance

Fecal samples from poultry on farms established after the ban of avoparcin (study farms) and from poultry on farms previously exposed to avoparcin (control farms) were examined for the presence of vancomycin-resistant enterococci (VRE). The samples were collected during the autumn and winter of 2001-2002. One isolate from each positive sample was selected, identified to species level, and examined for the presence of the vanA gene. The concentration of VRE and generic enterococci in the samples were also determined. In addition, the susceptibility to the ionophoric coccidiostat narasin was examined in a number of enterococcal isolates from poultry and in some enterococci of porcine origin that had not been exposed to narasin. VanA-type VRE was detected in samples from 64% of the study farms and 96% of the control farms. However, the concentration of VRE in the control samples was about six times larger than in the samples from the study farms. The minimum inhibitory concentration values for narasin differed between the poultry (1-4 mg/liter) and the porcine (0.25-0.5 mg/liter) isolates, indicating a decreased susceptibility towards narasin among enterococci from poultry.

Topics: Agriculture; Animals; Anti-Bacterial Agents; Chickens; Enterococcus; Feces; Glycopeptides; Gram-Positive Bacterial Infections; Norway; Poultry Diseases; Prevalence; Pyrans; Turkeys; Vancomycin Resistance

Glycopeptide resistant enterococci (GRE) isolated from animals and humans were characterised using both AFPL typing and genetic characterisation of the glycopeptide resistance transposon Tn1546. All isolates were collected in 1997 when the glycopeptide avoparcin was still being used as growth promoter. All investigated animal isolates were from mixed pig and poultry farms in the Netherlands and the human isolated from the farmers of these farms. A total of 24 isolates were investigated. AFLP and Tn1546 typing revealed that both pig and poultry related enterococcal and vanA transposon genotypes were found among the human isolates indicating spread of glycopeptide resistance from both pig and poultry to the farmers. These findings contradict previous finding that showed that GRE recovered from the general population were genotypically undistinguishable from GRE isolated from pigs but are in line with other studies that demonstrated spread of GRE from poultry to farmers in poultry farms.

Topics: Agriculture; Animals; Anti-Bacterial Agents; Chickens; DNA, Bacterial; Enterococcus; Feces; Glycopeptides; Gram-Positive Bacterial Infections; Humans; Netherlands; Phylogeny; Polymerase Chain Reaction; Poultry Diseases; Swine; Swine Diseases; Vancomycin Resistance

The number of vancomycin-resistant enterococci (VRE) relative to the total number of enterococci was determined in fecal samples from turkeys and three human populations in 1996, each with a different level of contact with turkeys, i.e., turkey farmers, turkey slaughterers, and (sub)urban residents. The percentage of VRE relative to the total enterococcal population (i.e., the degree of resistance) was low (2 to 4%) in all groups (except in six samples). No difference was observed between farmers who used avoparcin and those who did not. The pulsed-field gel electrophoresis (PFGE) patterns of the VRE isolates from the different populations were quite heterogeneous, but isolates with the same PFGE pattern were found among animal and human isolates, in addition to the isolates which were described previously (A. E. van den Bogaard, L. B. Jensen, and E. E. Stobberingh, N. Engl. J. Med. 337:1558-1559, 1997). Detailed molecular characterization of vanA-containing transposons from different isolates showed, that in addition to a previously reported strain, similar transposons were present in VRE isolates from turkeys and turkey farmers. Moreover, similar VanA elements were found not only in isolates with the same PFGE pattern but also in other strains from both humans and animals.

Topics: Animals; Anti-Bacterial Agents; Disease Transmission, Infectious; DNA Transposable Elements; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecalis; Feces; Glycopeptides; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Netherlands; Occupations; Suburban Population; Turkeys; Vancomycin Resistance

Australia is unique among Western countries in allowing animal use of this vancomycin-like antibiotic.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Animals, Domestic; Anti-Bacterial Agents; Bacterial Proteins; Drug Resistance, Microbial; Enterococcus; Gene Expression Regulation, Bacterial; Glycopeptides; Gram-Positive Bacterial Infections; Guidelines as Topic; Humans; Serine-Type D-Ala-D-Ala Carboxypeptidase; Vancomycin

There are major differences in the epidemiology of vancomycin-resistant enterococci (VRE) between the United States and Europe. In contrast with Europe, VRE in the United States are resistant to many antibiotics, and there appears to be less genetic variability among these isolates. European VRE of human origin are usually susceptible to many other antibiotics and are highly polyclonal. These clinical isolates have the same susceptibility profiles as VRE isolated from animals. The differences in the spread of VRE between the United States and Europe might be explained by the overconsumption of glycopeptides and other antibiotics in hospitals in the United States and the use of avoparcin as a growth promotor in Europe.

Topics: Animals; Animals, Domestic; Anti-Bacterial Agents; Cross Infection; Disease Vectors; Drug Resistance, Microbial; Drug Resistance, Multiple; Enterococcus; Europe; Glycopeptides; Gram-Positive Bacterial Infections; Humans; Microbial Sensitivity Tests; Practice Patterns, Physicians'; Prevalence; United States; Vancomycin

Topics: Animal Diseases; Animals; Anti-Bacterial Agents; Drug Resistance, Microbial; Enterococcus; Europe; Glycopeptides; Gram-Positive Bacterial Infections; Legislation, Drug; Legislation, Veterinary; Vancomycin

We determined the association between the use of the glycopeptide antibiotic avoparcin as a growth promoter and the occurrence of Enterococcus faecium (VREF) with high-level resistance to vancomycin (MIC > or = 64 micrograms ml-1) on poultry and pig farms. The investigations were conducted as retrospective cohort studies, where groups of farms exposed or not exposed to avoparcin between September 1994 and April 1995 were compared. In poultry, the association between the use of avoparcin and the occurrence of VREF was confounded by the use of broad-spectrum antibiotics, and the adjusted relative risk was 2.9 (1.4-5.9). In pigs, the association had a similar magnitude with a non-adjusted relative risk of 3.3 (0.9-12.3). The similar findings in the two studies provide evidence in favour of a causal association between the use of avoparcin and the occurrence of VREF on farms, and suggest that food animals constitute a potential reservoir of infection for VREF in humans.

Topics: Animals; Anti-Bacterial Agents; Antibodies, Bacterial; Chickens; Cohort Studies; Denmark; Disease Susceptibility; Drug Resistance, Microbial; Enterococcus faecium; Female; Glycopeptides; Gram-Positive Bacterial Infections; Growth Substances; Male; Poultry; Poultry Diseases; Retrospective Studies; Specific Pathogen-Free Organisms; Swine; Swine Diseases; Vancomycin

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Chickens; Drug Resistance, Microbial; Enterococcus; Enterococcus faecalis; Enterococcus faecium; Glycopeptides; Gram-Positive Bacterial Infections; Humans; London; Opportunistic Infections; Teicoplanin; Vancomycin