Phenotypic and Molecular Characterization of Plasmid-Mediated Virulence and Antimicrobial Resistance Traits among Multidrug Resistant Enterococcus spp. in Egypt

Enterococcus spp. are remarkable multidrug resistant (MDR) bacteria that are causing serious healthcare-associated infections. The current study investigated the frequency of Enterococcus spp., antimicrobial susceptibility, biofilm formation and the presence of some plasmid-mediated virulence characters and antimicrobial resistance determinants in enterococcal isolates from Egyptian hospitals in Cairo. Enterococcus bacterial isolates were recovered from different clinical specimens and identified using biochemical testing and KB005A HiStrep™ identification kit. Kirby-Bauer disc diffusion method and/or broth microdilution method were used to determine the antimicrobial susceptibility patterns. Phenotypic assays were performed to study biofilm formation and cytolysin and gelatinase production. PCR assays targeting the plasmid-carried genes aac(6’)-aph(2’), aph(3)-IIIa, vanA, agg and cylA were performed. In this study, 50 isolates of diverse Enterococcus spp. were identified with E. faecium was the most frequently isolated one. High resistance profiles were determined against tested antimicrobials and all isolates were MDR. Moderate biofilm formation was detected in 20% of isolates, 18% showed complete blood hemolysis and 12% produced gelatinase. All isolates carried the tested aminoglycosides resistance genes, while vanA was found only in 4 isolates (8%). The virulence genes agg and cylA were detected in 4% and 32% of isolates, respectively. In conclusion, E. faecium was the most prevalent species. The entire isolates set were MDR and the plasmid-carried aminoglycoside resistance genes were extensively disseminated among MDR isolates. Thus, regular surveillance studies, from the area of study or other geographical regions in Egypt, and strict infection control measures are required to monitor the emerging MDR enterococci.

Download Full-text

Rethinking Manure Application: Increase in Multidrug-Resistant Enterococcus spp. in Agricultural Soil Following Chicken Litter Application

Microorganisms ◽

10.3390/microorganisms9050885 ◽

2021 ◽

Vol 9 (5) ◽

pp. 885

Author(s):

Dorcas Oladayo Fatoba ◽

Akebe Luther King Abia ◽

Daniel G. Amoako ◽

Sabiha Y. Essack

Keyword(s):

Antimicrobial Resistance ◽

Agricultural Soil ◽

Multidrug Resistant ◽

Diffusion Method ◽

Resistant Bacteria ◽

Manure Application ◽

Unamended Soil ◽

Enterococcus Spp ◽

Chicken Litter ◽

Amended Soil

The current study investigated the impact of chicken litter application on the abundance of multidrug-resistant Enterococcus spp. in agricultural soil. Soil samples were collected from five different strategic places on a sugarcane farm before and after manure application for four months. Chicken litter samples were also collected. Enterococci were enumerated using the Enterolert®/Quanti-Tray 2000® system and confirm and differentiated into species using real-time PCR. The antibiotic susceptibility profile of the isolates was determined using the disk diffusion method following the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. The overall mean bacterial count was significantly higher (p < 0.05) in manure-amended soil (3.87 × 107 MPN/g) than unamended soil (2.89 × 107 MPN/g). Eight hundred and thirty-five enterococci (680 from soil and 155 from litter) were isolated, with E. casseliflavus being the most prevalent species (469; 56.2%) and E. gallinarum being the least (16; 1.2%). Approximately 56% of all the isolates were resistant to at least one antibiotic tested, with the highest resistance observed against tetracycline (33%) and the lowest against chloramphenicol (0.1%); 17% of E. faecium were resistant to quinupristin-dalfopristin. Additionally, 27.9% (130/466) of the isolates were multidrug-resistant, with litter-amended soil harbouring more multidrug-resistant (MDR) isolates (67.7%; 88/130) than unamended soil (10.0%; 13/130). All isolates were susceptible to tigecycline, linezolid and gentamicin. About 7% of the isolates had a multiple antimicrobial resistance index > 0.2, indicative of high antibiotic exposure. Although organic fertilizers are regarded as eco-friendly compared to chemical fertilizers for improving soil fertility, the application of untreated animal manure could promote the accumulation of antibiotics and their residues and antibiotic-resistant bacteria in the soil, creating an environmental reservoir of antimicrobial resistance, with potential human and environmental health risks.

Download Full-text

Serotype distribution, antimicrobial susceptibility, antimicrobial resistance genes and virulence genes of Salmonella isolated from a pig slaughterhouse in Yangzhou, China

AMB Express ◽

10.1186/s13568-019-0936-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Quan Li ◽

Jian Yin ◽

Zheng Li ◽

Zewei Li ◽

Yuanzhao Du ◽

...

Keyword(s):

Public Health ◽

Antimicrobial Resistance ◽

Resistance Genes ◽

Antimicrobial Susceptibility ◽

Virulence Genes ◽

Multidrug Resistant ◽

Resistance Rate ◽

Economic Losses ◽

Production Chain ◽

Antimicrobial Resistance Genes

AbstractSalmonella is an important food-borne pathogen associated with public health and high economic losses. To investigate the prevalence and the characteristics of Salmonella in a pig slaughterhouse in Yangzhou, a total of 80 Salmonella isolates were isolated from 459 (17.43%) samples in 2016–2017. S. Derby (35/80, 43.75%) was the most prevalent, followed by S. Rissen (16/80, 20.00%) and S. Newlands (11/80, 13.75%). The highest rates of susceptibility were observed to cefoxitin (80/80, 100.0%) and amikacin (80/80, 100.0%), followed by aztreonam (79/80, 98.75%) and nitrofurantoin (79/80, 98.75%). The highest resistance rate was detected for tetracycline (65/80, 81.25%), followed by ampicillin (60/80, 75.00%), bactrim (55/80, 68.75%), and sulfisoxazole (54/80, 67.50%). Overall, 91.25% (73/80) of the isolates were resistant to at least one antibiotic, while 71.25% (57/80) of the isolate strains were multidrug resistant in the antimicrobial susceptibility tested. In addition, 86.36% (19/22) of the 22 antimicrobial resistance genes in the isolates were identified. Our data indicated that the resistance to certain antimicrobials was significantly associated, in part, with antimicrobial resistance genes. Furthermore, 81.25% (65/80) isolates harbored the virulence gene of mogA, of which 2 Salmonella Typhimurium isolates carried the mogA, spvB and spvC virulence genes at the same time. The results showed that swine products in the slaughterhouse were contaminated with multidrug resistant Salmonella commonly, especially some isolates carry the spv virulence genes. The virulence genes might facilitate the dissemination of the resistance genes to consumers along the production chain, suggesting the importance of controlling Salmonella during slaughter for public health.

Download Full-text

Coagulase-negative staphylococcal bloodstream and prosthetic-device-associated infections: the role of biofilm formation and distribution of adhesin and toxin genes

Journal of Medical Microbiology ◽

10.1099/jmm.0.075259-0 ◽

2014 ◽

Vol 63 (11) ◽

pp. 1500-1508 ◽

Cited By ~ 20

Author(s):

Nikolaos Giormezis ◽

Fevronia Kolonitsiou ◽

Antigoni Foka ◽

Eleanna Drougka ◽

Apostolos Liakopoulos ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Multilocus Sequence Typing ◽

Biofilm Formation ◽

Bloodstream Infections ◽

Multidrug Resistant ◽

Prosthetic Device ◽

Coagulase Negative Staphylococci ◽

Toxin Genes ◽

High Level

Coagulase-negative staphylococci (CNS), especially Staphylococcus epidermidis and Staphylococcus haemolyticus, have emerged as opportunistic pathogens in immunocompromised patients and those with indwelling medical devices. In this study, CNS recovered from patients with bloodstream infections (BSIs) or prosthetic-device-associated infections (PDAIs) were compared in terms of biofilm formation, antimicrobial resistance, clonal distribution, and carriage of adhesin and toxin genes. A total of 226 CNS isolates (168 S. epidermidis and 58 S. haemolyticus) recovered from hospital inpatients with BSIs (100 isolates) or PDAIs (126 isolates) were tested for biofilm formation, antimicrobial susceptibility, and mecA, ica operon, adhesin (aap, bap, fnbA, atlE, fbe) and toxin (tst, sea, sec) genes. The selected CNS were classified into pulsotypes by PFGE and assigned to sequence types by multilocus sequence typing. In total, 106/226 isolates (46.9 %) produced biofilm, whereas 150 (66.4 %) carried the ica operon. Most isolates carried mecA and were multidrug resistant (90.7 %). CNS recovered from BSIs were significantly more likely to produce biofilm (P = 0.003), be resistant to antimicrobials and carry mecA (P<0.001), as compared with isolates derived from PDAIs. CNS from PDAIs were more likely to carry the aap and bap genes (P = 0.006 and P = 0.045, respectively). No significant differences in the carriage of toxin genes were identified (P>0.05). Although PFGE revealed genetic diversity, especially among S. epidermidis, analysis of representative strains from the main PFGE types by multilocus sequence typing revealed three major clones (ST2, ST5 and ST16). A clonal relationship was found with respect to antimicrobial susceptibility and ica and aap gene carriage, reinforcing the premise of clonal expansion in hospital settings. The results of this study suggest that the pathogenesis of BSIs is associated with biofilm formation and high-level antimicrobial resistance, whereas PDAIs are related to the adhesion capabilities of S. epidermidis and S. haemolyticus strains.

Download Full-text

Antimicrobial Resistance and Virulence Determination of Enterococcus spp. isolated from Hospital Environment in Iran

10.21203/rs.3.rs-118272/v1 ◽

2020 ◽

Author(s):

Saba Asgharzadeh Marghmalek ◽

Reza Valadan ◽

Mehrdad Gholami ◽

Mohtaram Nasrolahei ◽

Hamid Reza Goli

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Pathogenic Bacteria ◽

Antibiotic Resistance Genes ◽

Multidrug Resistant ◽

Hospital Environment ◽

Virulence Determinants ◽

Environmental Isolates ◽

Antimicrobial Resistance Genes ◽

Enterococcus Spp

Abstract Background: The role of the hospital environment as a source of pathogenic bacteria in recent studies has been poorly investigated. This study investigated the distribution of antimicrobial resistance genes and virulence determinants in Enterococcus species isolated from hospital environment in Sari, Iran. A total of 90 enterococci isolates were identified and species identification confirmed with specific primers. Seven resistance genes and two virulence associated genes were evaluated molecularly by multiplex polymerase chain reaction. Results: Of the 90 enterococcal isolates, 42 (46.66%), and 48 (53.33%) were identified as E. faecalis, and E. faecium, respectively. Also, 28 (66.6%) E. faecalis and 18 (37.5%) E. faecium isolates were multidrug-resistant (MDR). Among all 90 environmental isolates 54 (60%), 54 (60%), 8 (8.8%), 8 (8.8%), 60 (66.6%), 26 (28.8%), and 24 (26.6%) isolates contained tetM, tetL, vanA, vanB, ermB, aac (6´)-Ie-aph (2´´)-Ia, and aph (3´)-IIIa, respectively. Moreover, 88 (97.7%) and 16 (17.7%) isolates were detected as esp and ace positive ones, correspondingly. Conclusions: This report showed that the environmental isolates of Enterococcus are the major sources of antibiotic resistance genes that can transfer them to the clinical isolates of bacteria in hospital settings. An effective following strategy should be organized to clearance and stop emergence of these pathogenic bacteria.

Download Full-text

Antimicrobial Susceptibility and Frequency of bla and qnr Genes in Salmonella enterica Isolated from Slaughtered Pigs

Antibiotics ◽

10.3390/antibiotics10121442 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1442

Author(s):

Alyzza Marie B. Calayag ◽

Kenneth W. Widmer ◽

Windell L. Rivera

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Foodborne Pathogens ◽

Antimicrobial Susceptibility ◽

Salmonella Enterica ◽

Multidrug Resistant ◽

Major Product ◽

Hog Industry ◽

Antimicrobial Resistance Genes ◽

Severe Infections

Salmonella enterica is known as one of the most common foodborne pathogens worldwide. While salmonellosis is usually self-limiting, severe infections may require antimicrobial therapy. However, increasing resistance of Salmonella to antimicrobials, particularly fluoroquinolones and cephalosporins, is of utmost concern. The present study aimed to investigate the antimicrobial susceptibility of S. enterica isolated from pork, the major product in Philippine livestock production. Our results show that both the qnrS and the blaTEM antimicrobial resistance genes were present in 61.2% of the isolates. While qnrA (12.9%) and qnrB (39.3%) were found less frequently, co-carriage of blaTEM and one to three qnr subtypes was observed in 45.5% of the isolates. Co-carriage of blaTEM and blaCTX-M was also observed in 3.9% of the isolates. Antimicrobial susceptibility testing revealed that the majority of isolates were non-susceptible to ampicillin and trimethoprim/sulfamethoxazole, and 13.5% of the isolates were multidrug-resistant (MDR). MDR isolates belonged to either O:3,10, O:4, or an unidentified serogroup. High numbers of S. enterica carrying antimicrobial resistance genes (ARG), specifically the presence of isolates co-carrying resistance to both β-lactams and fluoroquinolones, raise a concern on antimicrobial use in the Philippine hog industry and on possible transmission of ARG to other bacteria.

Download Full-text

Biofilm formation, antimicrobial susceptibility and virulence genes of Uropathogenic Escherichia coli isolated from clinical isolates in Uganda

10.21203/rs.2.19141/v2 ◽

2020 ◽

Author(s):

Paul Katongole ◽

Fatuma Nalubega ◽

Najjuka Christine Florence ◽

Benon Asiimwe ◽

Irene Andia

Keyword(s):

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Biofilm Formation ◽

Virulence Genes ◽

Clinical Isolates ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Cross Sectional ◽

E Coli ◽

Tract Infections

Abstract Introduction: Uropathogenic E. coli is the leading cause of Urinary tract infections (UTIs), contributing to 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. Biofilm forming Uropathogenic E. coli are associated with persistent and chronic inflammation leading to complicated and or recurrent UTIs. Biofilms provide an environment for poor antibiotic penetration and horizontal transfer of virulence genes which favors the development of Multidrug-resistant organisms (MDRO). Understanding biofilm formation and antimicrobial resistance determinants of Uropathogenic E. coli strains will provide insight into the development of treatment options for biofilm-associated UTIs. The aim of this study was to determine the biofilm forming capability, presence of virulence genes and antimicrobial susceptibility pattern of Uropathogenic E. coli isolates in Uganda. Methods: This was a cross-sectional study carried in the Clinical Microbiology and Molecular biology laboratories at the Department of Medical Microbiology, Makerere University College of Health Sciences. We randomly selected 200 Uropathogenic E. coli clinical isolates among the stored isolates collected between January 2018 and December 2018 that had significant bacteriuria (>105 CFU). All isolates were subjected to biofilm detection using the Congo Red Agar method and Antimicrobial susceptibility testing was performed using the Kirby disk diffusion method. The isolates were later subjected PCR for the detection of Urovirulence genes namely; Pap, Fim, Sfa, Afa, Hly and Cnf, using commercially designed primers.Results: In this study, 62.5% (125/200) were positive biofilm formers and 78% (156/200) of these were multi-drug resistant (MDR). The isolates were most resistant to Trimethoprim sulphamethoxazole and Amoxicillin (93%) followed by gentamycin (87%) and the least was imipenem (0.5%). Fim was the most prevalent Urovirulence gene (53.5%) followed by Pap (21%), Sfa (13%), Afa (8%), Cnf (5.5%) and Hyl (0%).Conclusions: We demonstrate a high prevalence of biofilm-forming Uropathogenic E. coli strains that are highly associated with the MDR phenotype. We recommend routine surveillance of antimicrobial resistance and biofilm formation to understand the antibiotics suitable in the management of biofilm-associated UTIs.

Download Full-text

Study of genetic diversity, biofilm formation, and detection of Carbapenemase, MBL, ESBL, and tetracycline resistance genes in multidrug-resistant Acinetobacter baumannii isolated from burn wound infections in Iran

Antimicrobial Resistance and Infection Control ◽

10.1186/s13756-019-0612-5 ◽

2019 ◽

Vol 8 (1) ◽

Cited By ~ 2

Author(s):

Reza Ranjbar ◽

Abbas Farahani

Keyword(s):

Antimicrobial Resistance ◽

Acinetobacter Baumannii ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Tetracycline Resistance ◽

Multidrug Resistant ◽

Control Measures ◽

Wound Infections ◽

Burn Wound ◽

Cross Sectional

Abstract Background Antimicrobial resistance in multidrug-resistant Acinetobacter baumannii (MDR-AB) isolated from burn wound infections is a major concern in intensive care or burns units worldwide, and molecular studies are considered critical strategies for control of MDR-AB outbreaks in this regard. Thus, in this study, antibiotic resistance, biofilm-forming ability, molecular epidemiology of MDR A. baumannii strains recovered from patients with burns were investigated in three major hospital centers of Iran. Methods In this cross-sectional research, 163 non-repetitive A. baumannii strains were tested for susceptibility to antimicrobial agents. Polymerase chain reaction (PCR) was performed to characterize ambler classes A, B, and D β-lactamases, ISAba1 and integrons, biofilm formation was also investigated. Clonal relatedness was analyzed using Pulsed-Field Gel Electrophoresis (PFGE). Results Among 163 A. baumannii strains collected, 94.5% of them were Carbapenem-Non-Susceptible A. baumannii (CNSAB) and also 90.1 and 52.2% of them were Metallo-β-Lactamases (MBL) and Extended-Spectrum β-Lactamases (ESBL) producing isolates, respectively. Colistin and polymyxin B exhibited excellent activity against CNSAB strains. High prevalence of blaOXA − 23-like (85.1%), blaVIM (60.5%), blaPER − 1 (42.3%), tetB (67.8%), and Class 1 integrons (65.6%) were identified in CNSAB strains. ISAba1 element was associated with 42 (25.8%) and 129 (98.5%) of blaOXA-51-like and blaOXA-23-like genes, respectively. 6 clusters with the ability to form strong biofilms were found to be dominant and endemic in our entire areas. Conclusions Results of the present study show that antimicrobial resistance in CNSAB isolates from burn wound infections in monitored hospitals in Iran is multifactorial, and also findings of the study suggested that local antibiotic prescription policies should be regularly reviewed, and efficient infection control measures should be observed. Therefore, further strengthening of surveillance of antimicrobial resistance is urgently needed in these regions.

Download Full-text

Antimicrobial Resistance in Enterococcus spp. Strains Isolated from Organic Chicken, Conventional Chicken, and Turkey Meat: A Comparative Survey

Journal of Food Protection ◽

10.4315/0362-028x-70.4.1021 ◽

2007 ◽

Vol 70 (4) ◽

pp. 1021-1024 ◽

Cited By ~ 30

Author(s):

J. M. MIRANDA ◽

M. GUARDDON ◽

A. MONDRAGÓN ◽

B. I. VÁZQUEZ ◽

C. A. FENTE ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Common Species ◽

Multidrug Resistant ◽

Chicken Meat ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Turkey Meat ◽

Enterococcus Spp ◽

Resistant Strains ◽

Resistance Data

The mean counts of Enterococcus spp. were determined for 30 samples each of organic chicken meat, conventional chicken meat, and turkey meat, and differences for Enterococcus contamination in meat were determined. Two enterococci strains from each sample were isolated to obtain a total of 180 strains, and resistance to ampicillin, chloramphenicol, doxycycline, ciprofloxacin, erythromycin, gentamicin, nitrofurantoin, and vancomycin was determined by a disk diffusion method. Average counts obtained showed that Enterococcus mean counts from organic chicken meat (3.18 log CFU/g) were significantly higher than those obtained from conventional chicken meat (2.06 log CFU/g) or conventional turkey meat (1.23 log CFU/g). However, the resistance data obtained showed that isolates from organic chicken meat were less resistant than enterococci isolates from conventional chicken meat to ampicillin (P = 0.0067), chloramphenicol (P = 0.0154), doxycycline (P = 0.0277), ciprofloxacin (P = 0.0024), erythromycin (P = 0.0028), and vancomycin (P = 0.0241). In addition, isolates from organic chicken were less resistant than conventional turkey meat isolates to ciprofloxacin (P = 0.001) and erythromycin (P = 0.0137). Multidrug-resistant isolates were found in every group tested, but rates of multidrug-resistant strains were significantly higher in conventional chicken and turkey than those obtained from organic chicken meat. Enterococcus faecalis was the most common species isolated from organic chicken (36.67%), whereas Enterococcus durans was the most common species isolated from conventional chicken (58.33%) and turkey (56.67%). The rates obtained for antimicrobial resistance suggest that although organic chicken meat may have higher numbers of Enterococcus, these bacteria present a lower level of antimicrobial resistance.

Download Full-text

Antimicrobial Resistance and Biofilm Formation Capacity of Salmonella enterica Serovar Enteritidis Strains Isolated from Poultry and Humans in Poland

Pathogens ◽

10.3390/pathogens9080643 ◽

2020 ◽

Vol 9 (8) ◽

pp. 643

Author(s):

Katarzyna Ćwiek ◽

Kamila Korzekwa ◽

Aleksandra Tabiś ◽

Jacek Bania ◽

Gabriela Bugla-Płoskońska ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Salmonella Enterica ◽

Biofilm Formation ◽

Multidrug Resistant ◽

Animal Origin ◽

Human Feces ◽

Salmonella Enterica Serovar Enteritidis ◽

Biofilm Growth ◽

Food Of Animal Origin

Salmonella enterica ser. Enteritidis (S. enterica ser. Enteritidis) is the most frequently detected serovar in human salmonellosis, and its ability to produce a biofilm and the risk of transmission from animals and food of animal origin to humans are significant. The main aim of the present work was to compare S. enterica ser. Enteritidis strains isolated from poultry and human feces in terms of resistance profiles, prevalence of selected resistance genes, and their potential for biofilm formation, by assessing their biofilm growth intensity, the prevalence and expression of selected genes associated with this phenomenon, and the correlation between increased antimicrobial resistance and biofilm formation ability of the two tested groups of S. enterica ser. Enteritidis. This study showed a difference in antimicrobial resistance (minimal inhibitory concentration value) between S. enterica ser. Enteritidis groups; however, the majority of multidrug-resistant (MDR) strains were isolated from poultry (environmental samples from chicken broilers, turkey broilers, and laying hens). Differences in the prevalence of resistance genes were observed; the most common gene among poultry strains was floR, and that among strains from humans was blaTEM. S. enterica ser. Enteritidis strains isolated from poultry under the tested incubation conditions exhibited better biofilm growth than strains isolated from humans. A higher level of gene expression associated with the production of cellulose was only detected in the S48 strain isolated from poultry. On the other hand, increased expression of genes associated with quorum sensing was observed in two strains isolated from poultry farms and one strain isolated from human feces.

Download Full-text

Investigation of antimicrobial resistance in pigeons (Columba livia domestica) using indicator bacteria

Journal of the Hellenic Veterinary Medical Society ◽

10.12681/jhvms.23632 ◽

2020 ◽

Vol 71 (2) ◽

pp. 2095

Author(s):

Ö ASLANTAŞ ◽

N. GÖVCE

Keyword(s):

Antimicrobial Resistance ◽

Columba Livia ◽

Cloacal Swab ◽

Control Measures ◽

Current Status ◽

Diffusion Method ◽

Resistant Bacteria ◽

E Coli ◽

Specific Pcr ◽

Enterococcus Spp

The aim of this study was to determine the prevalence of antibiotic resistance as well as presence of resistance-associated genes in Escherichia coli and Enterococcus spp. strains isolated from pigeons. One hundred and fifty cloacal swabs were collected from apparently healthy pigeons in Hatay, Turkey, between March 2014 and June 2014. Antimicrobial susceptibilities of the isolates were tested with disc diffusion method, and resistance genes were investigated by polymerase chain reaction (PCR). E. coli were isolated from 94.7% (142) of the examined cloacal swab samples. E. coli isolates revealed higher resistance rates to tetracycline (51.4%) and ampicillin (50%), followed bynalidixic acid (19.7%), streptomycin (12.7%), amoxycillin-clavulanic acid (15.5%), trimethoprim-sulfamethoxazole (10.6%), cephalothin (7.0%), ciprofloxacin (6.3%), kanamycin (4.9%), gentamicin (4.2%), tobramycin (4.2%), ceftazidime (4.2%), cefotaxime (4.2%), chloramphenicol (2.8%), aztreonam (2.8%), and cefoxitin (0.7%), respectively. Twentyeight (%19.7) E. coli isolates were susceptible to all tested antimicrobials. A total of 136 (90.7%) Enterococcus spp. were isolated and species distribution of the isolates was determined by species-specific PCR. The isolates were identified as 64 (47.1%) E. hirae, 17 (12.5%) E. faecium, 8 (5.9%) E. faecalis, 4 (2.9%) E. columbea, and 2 (1.5%) E. durans. The rest of the isolates (30.1%) were identified as Enterococcus spp. with the used primers. Enterococcus spp. were resistant to tetracycline (67.6%), erythromycin (23.5%), rifampicin (17.6%), chloramphenicol (6.6%) and ciprofloxacin (5.9%). By contrast, 38 (27.9%) Enterococcus spp. were sensitive to all tested antimicrobials. The data obtained in the study showed that pigeons were carriers of antimicrobial resistant E. coli and Enterococcus spp. in their intestinal microbiota, and may pose public health risk due to not only transmission of these resistant bacteria to humans but also contamination of the environment. The current status of antimicrobial resistance in different animal species should be continuosly monitored and control measures should also be taken.

Download Full-text