scholarly journals Distribution of Antibiotic Resistance Genes in Enterococcus spp. Isolated from Mastitis Bovine Milk

2016 ◽  
Vol 66 (3) ◽  
pp. 336-346 ◽  
Author(s):  
Goksel Erbas ◽  
Ugur Parin ◽  
Suheyla Turkyilmaz ◽  
Nese Ucan ◽  
Mehmet Ozturk ◽  
...  

AbstractIn this study, determination of enterococcus species that were isolated from mastitic milk samples, investigation of their susceptibilities to antibiotics and identification of the existence of resistance genes in resistant strains were conducted. The specimens consist of 600 mastitic milk samples that were collected from 242 cows. Isolation of enterococcus was carried out in selective media and 94 (15.6%)Enterococcusspp. were isolated. A total of 94 species of Enterococci were identified using both sequencing and polymerase chain reaction (PCR).Enterococcusspp. isolates belong to 5 different species (E. faecalis, E. faecium, E. durans, E. hirae, E. mundtii) in sequence analysis and 4 different species (E. faecalis, E. faecium, E. durans, E. hirae) were identify by PCR method with specific primers. Analyzing 94 enterococcus strains by antibiotic sensitiveness test a high rate of resistance to tetracycline in 77 (81.9%) isolates was shown. Thetetresistance genes were identified as follows: 54 weretetM positive, 23 weretetK positive and 17 were positive ontetM andtetK. Resistance to erythromycin was established in 27 (28.7%) isolates (25ermB) while the chloramphenicol resistance gene was found in 10 (10.7%) of isolates and thecatgene was identified in nine samples and one isolate was resistant to vancomycin (1.06%) with theVanA gene confirmed. In conclusion, it was shown thatE. faecalishas the biggest role inenterococcusoriginated mastitis and these strains were found to be mostly resistant to tetracycline. One vancomycine resistant isolate that had theVanA gene was also determined.

2013 ◽  
Vol 37 (2) ◽  
pp. 156-160
Author(s):  
Mohammed J. Alwan

     The aim of this study was to determine the percentage of borne tuberculin infection in milk sample by using PCR.  (102) milk samples were collected from  cows , AL-Dejella (39) samples,  AL-Suara (20) samples cow station, AL-Fthalia (20) samples,  AL-Azezia (11) samples and AL-Twarege (12) samples (Iraq) during the period  July 10th   2010 to  Nov.30th   2010. The samples were examined by direct smear stained by Ziehle-Neelson stain, culture methods and confirmed the isolates by Polymerase Chain Reaction (PCR) assay. The results showed that  5, 102 (4.9%) milk samples were M. bovis positive that were detected by direct milk smear method and 10 out 102(9.8%) M.bovis +ve were detected by culture method and PCR assay. The results also showed that high percentage of bacterial isolates from milk samples AL-Dejella city show (12.8%) by culturing and PCR method followed by AL-Suara (10%), AL-Fthelia (10%), Al-Twarege (8.3%) but no bacterial isolation was recorded in AL-Azezia milk samples. This study concluded that M.bovis infection was spreading in dairy cow within the mentioned areas and PCR was more sensitive, rapid, and accurate technique for M.bovis infection diagnosis.


2019 ◽  
Vol 63 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Hanna Różańska ◽  
Aleksandra Lewtak-Piłat ◽  
Maria Kubajka ◽  
Marcin Weiner

Abstract Introduction: The aim of the study was to evaluate the occurrence of enterococci in inflammatory secretions from mastitic bovine udders and to assess their antimicrobial resistance. Material and Methods: A total of 2,000 mastitic milk samples from cows were tested in 2014–2017. The isolation of enterococci was performed by precultivation in buffered peptone water, selective multiplication in a broth with sodium azide and cristal violet, and cultivation on Slanetz and Bartley agar. The identification of enterococci was carried out using Api rapid ID 32 strep kits. The antimicrobial susceptibility was evaluated using the MIC technique. Results: Enterococci were isolated from 426 samples (21.3%). Enterococcus faecalis was the predominant species (360 strains), followed by E. faecium (35 isolates), and small numbers of others. The highest level of resistance was observed to lincomycin, tetracycline, quinupristin/dalfopristin (Synercid), erythromycin, kanamycin, streptomycin, chloramphenicol, and tylosin. Single strains were resistant to vancomycin and ciprofloxacin. All isolates were sensitive to daptomycin. E. faecalis presented a higher level of resistance in comparison to E. faecium, except to nitrofurantoin. Conclusion: The results showed frequent occurrence of enterococci in mastitic cow’s milk and confirmed the high rate of their antimicrobial resistance.


1998 ◽  
Vol 42 (7) ◽  
pp. 1563-1567 ◽  
Author(s):  
Dena Lyras ◽  
Christine Storie ◽  
Andrea S. Huggins ◽  
Paul K. Crellin ◽  
Trudi L. Bannam ◽  
...  

ABSTRACT The chloramphenicol resistance gene catD fromClostridium difficile was shown to be encoded on the transposons Tn4453a and Tn4453b, which were structurally and functionally related to Tn4451 fromClostridium perfringens. Tn4453a and Tn4453b excised precisely from recombinant plasmids, generating a circular form, as is the case for Tn4451. Evidence that this process is mediated by Tn4453-encodedtnpX genes was obtained from experiments which showed that in trans these genes complemented a Tn4451tnpXΔ1 mutation for excision. Nucleotide sequencing showed that the joint of the circular form generated by the excision of Tn4453a and Tn4453b was similar to that from Tn4451. These results suggest that the Tn4453-encoded TnpX proteins bind to similar DNA target sequences and function in a manner comparable to that of TnpX from Tn4451. Furthermore, it has been shown that Tn4453a and Tn4453b can be transferred to suitable recipient cells by RP4 and therefore are mobilizable transposons. It is concluded that, like Tn4451, they must encode a functional tnpZ gene and a targetoriT or RSA site. The finding that related transposable elements are present in C. difficile andC. perfringens has implications for the evolution and dissemination of antibiotic resistance genes and the mobile elements on which they are found within the clostridia.


2018 ◽  
Vol 85 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Mariela E Srednik ◽  
Valentine Usongo ◽  
Sarah Lépine ◽  
Xavier Janvier ◽  
Marie Archambault ◽  
...  

The study reported in this Research Communication was conducted to characteriseStaphylococcus aureusisolates recovered from mastitic bovine milk from dairy herds in Argentina. A total of 829 mastitic milk samples, both clinical and subclinical, were collected from 21 farms by veterinarians and submitted to the laboratory for testing from which 229S. aureusisolates were recovered, an isolation rate of 28·1%. These isolates were tested for susceptibility to the antibiotics penicillin, erythromycin and clindamycin. Of the 229 isolates, 53 (23·1%) were resistant to penicillin, 31 (13·5%) to erythromycin and 28 (12·2%) to clindamycin. All isolates were negative for themecA,mecC andpvlgenes by PCR. Southernblot hybridisation revealed that theermC gene was located on plasmid bands. Eighty isolates were randomly selected from the 229 for further characterisation. Restriction analysis of chromosomal DNA with Cf9I followed by PFGE of the 80 isolates revealed 23 distinct pulsotypes at 80% similarity. Seven major types (A, B, N, P, S, T, U and V) accounted for 68·7% of these isolates and 12 pulsotypes (A, B, F, G, J, K, M, N, P, S, T and U) occurred on more than one farm indicating genetic diversity within the farms. MLST of a representative isolate from dominant types identified the STs 97 705, 746, 2102 and 2187 with ST97 being the most predominant. Antibiotic susceptibility testing showed that 53·7% of the 80 randomly selected isolates were resistant to at least one of the three antibiotics tested. To our knowledge, this study represents the first large scale molecular studies onS. aureusisolates from dairy farms in Argentina.


1997 ◽  
Vol 64 (1) ◽  
pp. 77-86 ◽  
Author(s):  
DIDIER DUPONT ◽  
CHRISTELLE BAILLY ◽  
JEANNE GROSCLAUDE ◽  
JEAN-CLAUDE COLLIN

Two sandwich enzyme-linked immunosorbent assays (ELISA) have been developed for quantitation of bovine milk plasminogen and plasmin. The assays used two monoclonal antibodies, one specific for plasminogen and the other specific for plasminogen plus plasmin. Plasmin concentration was obtained by subtracting the first concentration from the second. The assays were sensitive (linear range, 5–75 ng/ml), repeatable (CV, 8 and 5% for plasmin and plasminogen titration respectively), specific (no cross reactivity with the major milk proteins) and directly applicable to skimmed milk with no particular pretreatment of the sample. However, ELISA did not permit complete titration of milk plasminogen and plasmin (only 60–90% could be quantified). This lack of accuracy was due to casein interfering with the plasmin–plasminogen titration by ELISA. Results obtained with ELISA or an enzymic technique on 20 milk samples collected from individual cows milked throughout pregnancy showed that the ELISA was particularly suitable for analysis of late lactation or mastitic milk where proteinase inhibitors interfered with enzymic quantitation.


Author(s):  
Alasdair T. M. Hubbard ◽  
Jenifer Mason ◽  
Paul Roberts ◽  
Christopher M. Parry ◽  
Caroline Corless ◽  
...  

AbstractA novel phenotype of Escherichia coli and Klebsiella pneumoniae resistant to piperacillin/tazobactam (TZP), but susceptible to carbapenems and 3rd generation cephalosporins has recently emerged. The resistance mechanism of this phenotype has been identified as hyperproduction of the β-lactamase blaTEM, however the mechanism of hyperproduction in isolates lacking promoter region mutations is not well understood. We sought to understand this mechanism by focussing on a pair of isolates obtained from an individual patient across two infection episodes and displaying within-patient evolution to TZP resistance. Following confirmation that the two isolates were clonal, we found that the TZP-resistant isolate hyperproduced a β-lactamase but lacked mutations within β-lactamase promoter regions. Hybrid assembly of long and short sequencing reads of the two isolates revealed both harboured a novel IS26-flanked composite transposon containing several antibiotic resistance genes, including blaTEM-1B, which was designated Tn6762. These resistance genes are also found to be present on a translocatable unit which had excised from Tn6762 in the TZP-resistant isolate. By replicating the evolutionary event leading to TZP resistance we were able to observe excision of the translocatable unit from Tn6762 following exposure to TZP and capture the TU in a plasmid containing a copy of IS26. Subsequent amplification of the TU, and by extension blaTEM-1B, leads to β-lactamase hyperproduction and TZP resistance. Despite a significant increase in gene copy number (P value = <0.0001), we found that the TZP-resistant isolate was as fit as the susceptible ancestor. This mechanism of gene amplification, and the subsequent hyperproduction, of blaTEM-1B is an important consideration when using genomic data to predict resistance/susceptibility to TZP.


Entecho ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 6-12
Author(s):  
Ivan Karpíšek ◽  
Jitka Zachová ◽  
Dana Vejmelková ◽  
Vladimír Sýkora

Aktivovaný kal na čistírnách odpadních vod je neustále vystavován nízkým koncentracím antimikrobiálních látek a dalších léčiv. To vyvolává otázku, jak mikroorganismy k těmto látkám na čistírně odpadních vod přistupují. Zda jsou schopny se v tomto prostředí na tyto látky adaptovat, degradovat je, případně je využít jako substrát. Nebo jestli jsou tyto látky aktivovaným kalem opomíjeny. Pro posouzení adaptace aktivovaného kalu byla využita metoda PCR pro sledování genů resistence a testy biologické rozložitelnosti. Pro testy byl využit aktivovaný kal z ČOV a kal adaptovaný v laboratorních SBR modelech při koncentracích antibiotik 500 ng∙l−1 a 500 μg∙l−1. Biologická rozložitelnost byla posuzována dle normy ČSN ISO 14593. Testované látky byly sledovány pomocí skupinového stanovení celkového anorganického uhlíku. Jako testované látky byly vybrány: benzylpenicilin, ampicilin, streptomycin, erythromycin, chloramfenikol, sulfamethoxazol a trimetoprim. Aktivovaný kal z čistírny odpadních vod neměl vyvinutou aktivitu k biodegradaci testovaných antibiotik. Je pravděpodobné, že vysoké zatížení snadno biologicky rozložitelným substrátem a krátké zdržení odpadní vody na ČOV, vede k tomu, že mikroorganismy aktivovaného kalu nejsou nuceny tyto látky aktivně utilizovat a brání se jim pouze tvorbou obranných mechanismů pomocí genů antibiotické resistence. Nízké koncentrace antibiotik v SBR modelech vytvářely selekční tlak na mikroorganismy a podněcovaly šíření genů antibiotické resistence. English Activated sludge in wastewater treatment plants is constantly exposed to low concentrations of antimicrobials and other drugs. This raises the question of how microorganisms approach to these substances in the sewage treatment plant. Whether they can adapt, degrade, or use antibiotics as a substrate in this environment or the activated sludge neglects these substances. To assess the adaptation of activated sludge, the PCR method for monitoring antibiotic resistance genes and biodegradability tests were used. These tests were carried out with activated sludge from WWTP and sludge adapted in laboratory SBR models at 500 ng∙l−1 and 500 μg∙l−1 of chosen antibiotics. Their biodegradability was assessed according to ČSN ISO 14593. The tested substances were monitored by group determination of total inorganic carbon. The chosen substances were: benzylpenicillin, ampicillin, streptomycin, erythromycin, chloramphenicol, sulfamethoxazole and trimethoprim. Activated sludge had no developed activity for biodegradation of tested antibiotics. It is likely that the high load of readily biodegradable substrate and the short retention of the wastewater at the WWTP lead to the activated sludge not being forced to actively utilize these substances and will only prevent from them by forming defence mechanisms using antibiotic resistance genes. Low concentrations of antibiotics in SBR models produced selective pressure on microorganisms and stimulated the spread of antibiotic resistance genes.


2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Mostafa Boroumand Boroumand ◽  
Mohsen Naghmachi ◽  
Mohammad Amin Ghatee

Background: Many bacteria can cause urinary tract infections (UTIs), among which Escherichia coli is the most common causative agent. E. coli strains are divided into eight phylogenetic groups based on the new Quadroplex-PCR method, which are different in terms of patterns of resistance to antibiotics, virulence, and environmental characteristics. Objectives: This study aimed to determine the phylogenetic groups and the prevalence of drug resistance genes in E. coli strains causing UTIs. Methods: In this descriptive cross-sectional study, 129 E. coli isolates obtained from the culture of patients with UTIs were evaluated for phylogenetic groups using the new method of Clermont et al. The identification of phylogenetic groups and antibiotic resistance genes was performed using the multiplex polymerase chain reaction (PCR) method. Results: In this study, concerning the distribution of phylogenetic groups among E. coli isolates, the phylogenetic group B2 (36.4%) was the most common phylogenetic group, followed by phylogroups C (13.2%), clade I (10.1%), D (9.3%), and A (3.1%) while groups B1 and F were not observed in any of the isolates, and 20.2% had an unknown state. Also, out of 129 E. coli isolates, the total frequency of tetA, tetB, sul1, sul2, CITM, DfrA, and qnr resistance genes was 59.7%, 66.7, 69, 62, 30.2, 23.3, and 20.2%, respectively. In this study, there was a significant relationship between antibiotics (P = 0.026), cefotaxime (P = 0.003), and nalidixic acid (P = 0.044) and E. coli phylogenetic groups. No significant relationship was observed between E. coli phylogenetic groups and antibiotic resistance genes. Conclusions: The results of this study showed that strains belonging to group B2 had the highest prevalence among other phylogroups, and also, the frequency of antibiotic resistance genes and drug-resistant isolates had a higher prevalence in this phylogroup. These results show that phylogroup B2 has a more effective role in causing urinary tract infections compared to other phylogroups, and this phylogroup can be considered a genetic reservoir of antibiotic resistance.


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