Frequency of virulence genes and antibiotic resistances inEnterococcusspp. isolates from wastewater and feces of domesticated mammals and birds, and wildlife

2010 ◽  
Vol 56 (9) ◽  
pp. 715-729 ◽  
Author(s):  
Martin Lanthier ◽  
Andrew Scott ◽  
David R. Lapen ◽  
Yun Zhang ◽  
Edward Topp
Keyword(s):  
Virulence Genes ◽  
Animal Husbandry ◽  
Antibiotic Use ◽  
Source Tracking ◽  
Virulence Determinants ◽  
Host Group ◽  
Specific Host ◽  
Enterococcus Spp ◽  
Group Resistance ◽  
Virulence Typing

Enterococci are gastrointestinal tract residents and also an important cause of nosocomial infections. To understand which species, virulence determinants, and antibiotic resistances are prevalent in enterococci shed by various hosts groups, a total of 1460 strains isolated from 144 fecal samples obtained from wastewater, domesticated mammals and birds, and wildlife were characterized. Identification of isolates to the species level showed that Enterococcus faecalis was dominant in domesticated mammals and birds and wildlife feces, whereas Enterococcus faecium was dominant among wastewater isolates, and that no single Enterococcus species could be associated with a specific host group. The frequency of 12 virulence determinants was evaluated among isolates, but no single virulence determinant could be associated with a specific host group. Resistance to 12 antibiotics was evaluated among isolates, and it was shown that the highest frequency of resistance at breakpoint concentration was found in domesticated mammals and birds (P ≤ 0.05 for 4 antibiotics). Our results suggests that (1) species identification and virulence typing of Enterococcus spp. isolates are not useful for the identification of the host groups responsible for fecal contamination of water by microbial source tracking and that (2) antibiotic use for clinical, veterinary, or animal husbandry practices is promoting resistance.

Virulence determinants and production of extracellular enzymes in Enterococcus spp. from surface water sources

2016 ◽  
Vol 73 (8) ◽  
pp. 1817-1824 ◽  
Author(s):  
Lesego Gertrude Molale ◽  
Cornelius Carlos Bezuidenhout
Keyword(s):  
Surface Water ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Extracellular Enzymes ◽  
Virulence Gene ◽  
Water Sources ◽  
Virulence Determinants ◽  
North West ◽  
Enterococcus Spp

Virulence factors in Enterococcus may be indicative of potential pathogenicity. The aim of this study was to determine the relationship between the presence of clinically relevant virulence genes, in Enterococcus spp. from environmental water, and their in vitro expression. One hundred and twenty-four Enterococcus isolates (seven species), from five surface water systems in the North West Province, South Africa, were screened for the presence of asa1, cylA, esp, gelE and hyl using polymerase chain reaction. The expression of cylA, hyl and gelE was determined by phenotypic assessments. Sixty-five percent of the isolates were positive for one virulence gene and 13% for two or more. Most frequently detected genes were gelE (32%) and cylA (28%). Enterococcal surface protein was absent in all isolates screened. The presence of virulence genes was correlated with their extracellular enzyme production. The results show that a large percentage of these environmental Enterococcus spp. possess virulence factors that could be expressed in vitro. This is a cause for concern and could have implications for individuals using this water for recreational and cultural purposes. Further investigation is required into the sources of these potential pathogenic Enterococcus isolates and measures to minimize their presence in water sources.

scholarly journals Burden, Antibiotic Resistance, and Clonality of Shigella spp. Implicated in Community-Acquired Acute Diarrhoea in Lilongwe, Malawi

2021 ◽  
Vol 6 (2) ◽  
pp. 63
Author(s):  
Abel F.N.D. Phiri ◽  
Akebe Luther King Abia ◽  
Daniel Gyamfi Amoako ◽  
Rajab Mkakosya ◽  
Arnfinn Sundsfjord ◽  
...  
Keyword(s):  
Real Time ◽  
Antibiotic Susceptibility ◽  
Virulence Genes ◽  
Shigella Flexneri ◽  
Acute Diarrhoea ◽  
Virulence Determinants ◽  
African Countries ◽  
Shigella Species ◽  
Shigella Spp ◽  
Sub Saharan

Although numerous studies have investigated diarrhoea aetiology in many sub-Saharan African countries, recent data on Shigella species’ involvement in community-acquired acute diarrhoea (CA-AD) in Malawi are scarce. This study investigated the incidence, antibiotic susceptibility profile, genotypic characteristics, and clonal relationships of Shigella flexneri among 243 patients presenting with acute diarrhoea at a District Hospital in Lilongwe, Malawi. Shigella spp. were isolated and identified using standard microbiological and serological methods and confirmed by identifying the ipaH gene using real-time polymerase chain reaction. The isolates’ antibiotic susceptibility to 20 antibiotics was determined using the VITEK 2 system according to EUCAST guidelines. Genes conferring resistance to sulfamethoxazole (sul1, sul2 and sul3), trimethoprim (dfrA1, dfrA12 and dfrA17) and ampicillin (oxa-1 and oxa-2), and virulence genes (ipaBCD, sat, ial, virA, sen, set1A and set1B) were detected by real-time PCR. Clonal relatedness was assessed using ERIC-PCR. Thirty-four Shigella flexneri isolates were isolated (an overall incidence of 14.0%). All the isolates were fully resistant to sulfamethoxazole/trimethoprim (100%) and ampicillin (100%) but susceptible to the other antibiotics tested. The sul1 (79%), sul2 (79%), sul3 (47%), dfrA12 (71%) and dfrA17 (56%) sulfonamide and trimethoprim resistance genes were identified; Oxa-1, oxa-2 and dfrA1 were not detected. The virulence genes ipaBCD (85%), sat (85%), ial (82%), virA (76%), sen (71%), stx (71%), set1A (26%) and set1B (18%) were detected. ERIC-PCR profiling revealed that the Shigella isolates were genetically distinct and clonally unrelated, indicating the potential involvement of genetically distinct S. flexneri in CA-AD in Malawi. The high percentage resistance to ampicillin and sulfamethoxazole/trimethoprim and the presence of several virulence determinants in these isolates emphasises a need for continuous molecular surveillance studies to inform preventive measures and management of Shigella-associated diarrhoeal infections in Malawi.

scholarly journals Transcription of Candidate Virulence Genes ofHaemophilus ducreyi during Infection of Human Volunteers

2001 ◽  
Vol 69 (3) ◽  
pp. 1483-1487 ◽  
Author(s):  
Robert E. Throm ◽  
Stanley M. Spinola
Keyword(s):  
Experimental Infection ◽  
Virulence Genes ◽  
Human Model ◽  
Specific Gene ◽  
Gene Products ◽  
Virulence Determinants ◽  
Reverse Transcription Pcr ◽  
Human Volunteers

ABSTRACT Haemophilus ducreyi expresses several putative virulence factors in vitro. Isogenic mutant-to-parent comparisons have been performed in a human model of experimental infection to examine whether specific gene products are involved in pathogenesis. Several mutants (momp, ftpA, losB, lst, cdtC, and hhdB) were as virulent as the parent in the human model, suggesting that their gene products did not play a major role in pustule formation. However, we could not exclude the possibility that the gene of interest was not expressed during the initial stages of infection. Biopsies of pustules obtained from volunteers infected with H. ducreyiwere subjected to reverse transcription-PCR. Transcripts corresponding to momp, ftpA, losB, lst, cdtB, and hhdA were expressed in vivo. In addition, transcripts for other putative virulence determinants such as ompA2, tdhA, lspA1, andlspA2 were detected in the biopsies. These results indicate that although several candidate virulence determinants are expressed during experimental infection, they do not have a major role in the initial stages of pathogenesis.

scholarly journals Genetic but No Phenotypic Associations between Biocide Tolerance and Antibiotic Resistance in Escherichia coli from German Broiler Fattening Farms

2021 ◽  
Vol 9 (3) ◽  
pp. 651
Author(s):  
Alice Roedel ◽  
Szilvia Vincze ◽  
Michaela Projahn ◽  
Uwe Roesler ◽  
Caroline Robé ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Acquired Resistance ◽  
Antibiotic Resistance Genes ◽  
Animal Husbandry ◽  
Metal Resistance ◽  
Resistant Bacteria ◽  
Virulence Determinants ◽  
Phylogenetic Distribution ◽  
Resistance Determinants

Biocides are frequently applied as disinfectants in animal husbandry to prevent the transmission of drug-resistant bacteria and to control zoonotic diseases. Concerns have been raised, that their use may contribute to the selection and persistence of antimicrobial-resistant bacteria. Especially, extended-spectrum β-lactamase- and AmpC β-lactamase-producing Escherichia coli have become a global health threat. In our study, 29 ESBL-/AmpC-producing and 64 NON-ESBL-/AmpC-producing E.coli isolates from three German broiler fattening farms collected in 2016 following regular cleaning and disinfection were phylogenetically characterized by whole genome sequencing, analyzed for phylogenetic distribution of virulence-associated genes, and screened for determinants of and associations between biocide tolerance and antibiotic resistance. Of the 30 known and two unknown sequence types detected, ST117 and ST297 were the most common genotypes. These STs are recognized worldwide as pandemic lineages causing disease in humans and poultry. Virulence determinants associated with extraintestinal pathogenic E.coli showed variable phylogenetic distribution patterns. Isolates with reduced biocide susceptibility were rarely found on the tested farms. Nine isolates displayed elevated MICs and/or MBCs of formaldehyde, chlorocresol, peroxyacetic acid, or benzalkonium chloride. Antibiotic resistance to ampicillin, trimethoprim, and sulfamethoxazole was most prevalent. The majority of ESBL-/AmpC-producing isolates carried blaCTX-M (55%) or blaCMY-2 (24%) genes. Phenotypic biocide tolerance and antibiotic resistance were not interlinked. However, biocide and metal resistance determinants were found on mobile genetic elements together with antibiotic resistance genes raising concerns that biocides used in the food industry may lead to selection pressure for strains carrying acquired resistance determinants to different antimicrobials.

DIFFERENCES IN GENOTYPE OF E. FAECALIS AND E. FAECIUM CLINICAL ISOLATES REGARDING CYTOLYSIN AND GELATINASE PRODUCTION IN BULGARIAN PATIENTS

2020 ◽  
Vol 18 (Suppl.1) ◽  
pp. 130-137
Author(s):  
R. Yordanova ◽  
S. Stanilova
Keyword(s):  
Virulence Genes ◽  
Clinical Isolates ◽  
University Hospitals ◽  
Gelatinase Activity ◽  
Non Invasive ◽  
Genotypic Analysis ◽  
Enterococcus Spp ◽  
Virulent Gene ◽  
One Year ◽  
Genotype Correlation

Purpose - compare the phenotype and genotype correlation of cytolysin and gelatinase production in clinical isolates Enterococcus spp. Materials and methods - 100 Enterococcus strains collected over a period of one year from inpatients of two Bulgarian university hospitals, were tested for phenotype production of cytolysin and gelatinase. Multiplex PCR was performed to screen the presence of gelE and cylA virulence genes. Results – 17% of the enterococcal isolates demonstrated only cytolysin production phenotypically. Gelatinase activity was found in 21% of the isolates. Only E. faecalis showed combined phenotypic production of cytolysin plus gelatinase (21%). Forty-five percent of the tested enterococci were identified negative for both hemolysin and gelatinase activity. GelE was the most prevalent virulent gene (48% of the isolates). CylA gene was present alone only in four non-invasive E. faecalis isolates. Twenty-six percent of the isolates possessed both cylA and gelE genes and 21% did not harbor any of the virulence factors genotypically. Conclusion - our results prove that it is appropriate to perform both phenotypic and genotypic analysis of the enterococci virulence profile in parallel in order to better characterize the strains, which in turn may serve to develop more effective methods to limit the spread of infections caused by these microorganisms.

Occurrence of virulence-associated genes in clinical Enterococcus faecalis strains isolated in Londrina, Brazil

2004 ◽  
Vol 53 (11) ◽  
pp. 1069-1073 ◽  
Author(s):  
Elisa Bittencourt de Marques ◽  
Sérgio Suzart
Keyword(s):  
Enterococcus Faecalis ◽  
Virulence Genes ◽  
Epidemiological Studies ◽  
Wide Distribution ◽  
Virulence Determinants ◽  
Simultaneous Presence ◽  
Common Pattern ◽  
Clinical Strains ◽  
Virulence Markers ◽  
Serious Infections

Epidemiological studies have reinforced the importance of Enterococcus faecalis in causing serious infections, and to date, our understanding of how certain virulence factors are involved in the pathogenesis of enterococcal infections is still limited. The aim of the present study was to examine the occurrence of known virulence determinants in a group of E. faecalis strains isolated from different clinical sources in Brazil. A total of 95 E. faecalis strains were investigated for the presence of nine virulence genes including aggA, cylA, cylB, cylM, eep, efaA, enlA, esp and gelE by using PCR. The data showed a relatively wide distribution of the virulence genes among the investigated strains. The clinical strains carried at least one and concomitantly up to as many as eight virulence markers, with two or three being the most common pattern. Most of the strains carried efaA (58.9 %), eep (58.9 %) and esp (57.9 %) genes, whereas the remaining virulence markers were detected in variable percentages ranging from 9.5 to 45 %. Simultaneous presence of virulence markers was observed among clinical strains regardless of their sources. In this study, the efaA + esp + gelE + profile was the virulence genotype most frequently detected among E. faecalis strains. Finally, there was no significant association between virulence markers and clinical sources.

The Future of Antibiotics and Meat

2016 ◽  
pp. 178-200 ◽  
Author(s):  
Talia Raphaely ◽  
Dora Marinova ◽  
Mira Marinova
Keyword(s):  
Antibiotic Resistance ◽  
Food Chain ◽  
Animal Husbandry ◽  
Meat Consumption ◽  
Antibiotic Use ◽  
Meat Production ◽  
Livestock Industry ◽  
Antibiotic Resistant ◽  
New Challenges ◽  
Food Animals

This chapter discusses antibiotic use in the livestock industry and potential ramifications for human health. Antibiotics are routinely administered to food animals, primarily at sub-therapeutic levels. The extensive use of antibiotics in global animal husbandry in quantities greater than used for humans is creating antibiotic resistance. There is evidence that antibiotic resistant organisms emerging in food animals transfer to humans through the food chain, environmental contamination, direct association with animals or through mobile resistant genetic elements resulting in co-resistance to other antibiotics. No new classes of antibiotics have been developed since the 1980s. Intensifying use of existing antibiotics for meat production poses new challenges for treating humans, needs to be taken seriously and dealt with urgently. This chapter argues that reduced meat consumption is an under-considered but essential part in any suite of solutions aimed at preserving the use of antibiotics for human treatment.

scholarly journals Oxytetracycline and Monensin Uptake by Tifton 85 Bermudagrass from Dairy Manure-Applied Soil

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 468
Author(s):  
Sheldon S. Hilaire ◽  
Barbara Bellows ◽  
Jeff A. Brady ◽  
James P. Muir
Keyword(s):  
Animal Husbandry ◽  
Soil Surface ◽  
Antibiotic Use ◽  
Dairy Manure ◽  
Human Medicine ◽  
Enzyme Linked Immunosorbent Assay ◽  
Forage Grass ◽  
Veterinary Antibiotics ◽  
Animal Products ◽  
Plant Matter

To address concerns regarding the potential impact of antibiotic use in animal husbandry on antibiotic resistance in humans, we conducted a greenhouse-based study examining uptake of the veterinary antibiotics oxytetracycline (OTC) and monensin (MON) by Tifton 85 Bermudagrass (T85), the most commonly grown forage grass in the southeastern U.S.A. Since oxytetracycline is used in both veterinary and human medicine, its accumulation in animal products could impact human resistance to this antibiotic. Monensin is not used in human medicine but has a high potential for accumulating in the environment. Our research examined antibiotic uptake by forage grass T85, the effect of dairy manure application on its uptake, and antibiotic retention in soil. We compared unspiked, wet dairy manure to wet dairy manure spiked with MON or OTC that was soil surface applied to pots or incorporated into soil. After 6 wk, plant stem/leaf and root tissue, as well as soil samples, were assessed for antibiotic residues using enzyme-linked immunosorbent assay (ELISA). Results confirmed Tifton 85 MON and OTC uptake. Six weeks after adding the antibiotics, the greatest plant matter OTC and MON contents were 157.9 ± 70.6 and 234.4 ± 19.6 µg kg−1, respectively, and 17.6 and 369.5 µg kg−1, respectively, for soil. When spiked with OTC, manure incorporation led to decreased OTC uptake by T85 tissue. Bioaccumulation of these antimicrobials in livestock and in the environment is a potential concern for animal, environmental, and human health.

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