Susceptibility of Meat Starter Cultures to Antimicrobials Used in Food Animals in Canada

2010 ◽  
Vol 73 (5) ◽  
pp. 916-922 ◽  
Author(s):  
R. P. CORDEIRO ◽  
T. DU ◽  
M. R. MULVEY ◽  
D. O. KRAUSE ◽  
R. A. HOLLEY

Lactic acid bacteria (LAB) are extensively used in the food industry for fermentation processes. However, it is possible that these bacteria may serve as a reservoir for antibiotic resistance genes that can be transferred to pathogens, giving rise to public health concerns. Animal operations that use antimicrobials as growth promotants have been linked to the origin of resistance due to the selective effect of low levels of antimicrobial used in this management strategy. The objective of this study was to determine the antimicrobial susceptibilities and mechanisms of resistance for 30 isolates of meat starter cultures commonly used in dry sausage fermentations to 20 antimicrobial agents. Susceptibility tests were performed by broth microdilution using Iso-Sensitest broth (90%, vol/vol) and de Man Rogosa Sharpe (MRS) broth (10%, vol/vol). The results showed that all 30 isolates exhibited resistance to at least three antimicrobials regardless of antimicrobial class while 17 or 30% of strains were resistant to antibiotics in three or six different classes, respectively. The incidence of antimicrobial resistance was higher among Pediococcus pentosaceus and lower for Staphylococcus carnosus strains. Genetic determinants for the lincosamide, macrolide, and tetracycline antimicrobials were not found using PCR. Phenotypic resistance in the absence of known resistance genes found here suggests that other mechanisms or genes might have contributed to the negative results. Further studies are needed to explore the genetic mechanisms underlying the prevalence of antibiotic resistance in Pediococcus species.

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 930
Author(s):  
Delia Gambino ◽  
Sonia Sciortino ◽  
Sergio Migliore ◽  
Lucia Galuppo ◽  
Roberto Puleio ◽  
...  

The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (blaTEM, blaOXA, tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.


2021 ◽  
Author(s):  
Farhan Yusuf ◽  
Kimberley Gilbride

Bacterial isolates found in aquatic ecosystems often carry antibiotic resistance genes (ARGs). These ARGs are often found on plasmids and transposons, which allows them to be proliferate throughout bacterial communities via horizontal gene transfer (HGT) causing dissemination of multidrug resistance. The increase in antibiotic resistance has raised concerns about the ability to continue to use these drugs to fight infectious diseases. Novel synthetic antibiotics like ciprofloxacin that are not naturally found in the environment were developed to prevent resistances. However, ciprofloxacin resistance has occurred through chromosomal gene mutations of type 2 topoisomerases or by the acquisition of plasmid-mediated quinolone resistances (PMQR). A particular PMQR, qnr genes, encoding for pentapeptide repeat proteins that confer low levels of quinolone resistance and protect DNA gyrase and topoisomerase IV from antibacterial activity. These qnr genes have been identified globally in both clinical and environmental isolates. The aim of this study was to determine the prevalence of ciprofloxacin-resistant bacteria in aquatic environments in the Greater Toronto Area and the potential dissemination of ciprofloxacin resistance. With the selective pressure of ciprofloxacin, we hypothesize that ciprofloxacin-resistant bacteria (CipR) in the environment may carry PMQR mechanisms while the sensitive population (CipS) would not carry PMQR genes. Isolates were tested for resistance to an additional 12 different antibiotics and identified using Sanger sequencing PCR products of the 16S rRNA gene. To determine which genes are responsible for ciprofloxacin resistance, multiplex PCR of associated qnr genes, qnrA, qnrB, and qnrS, was carried out on 202 environmental isolates. Our data demonstrate a similar prevalence of qnr genes was found in CipR (19%) and CipS (14%) populations suggesting that the presence of these genes was not necessarily correlated with the phenotypic resistance to the antibiotic. Furthermore, ciprofloxacinresistant bacteria were found in all locations at similar frequencies suggesting that resistance genes are widespread and could possibly arise through HGT events. Overall, determining the underlying cause and prevalence of ciprofloxacin resistance could help re-establish the effectiveness of these antimicrobial compounds.


2019 ◽  
Vol 63 (4) ◽  
Author(s):  
G. Terrance Walker ◽  
Julia Quan ◽  
Stephen G. Higgins ◽  
Nikhil Toraskar ◽  
Weizhong Chang ◽  
...  

ABSTRACT We developed a rapid high-throughput PCR test and evaluated highly antibiotic-resistant clinical isolates of Escherichia coli (n = 2,919), Klebsiella pneumoniae (n = 1,974), Proteus mirabilis (n = 1,150), and Pseudomonas aeruginosa (n = 1,484) for several antibiotic resistance genes for comparison with phenotypic resistance across penicillins, cephalosporins, carbapenems, aminoglycosides, trimethoprim-sulfamethoxazole, fluoroquinolones, and macrolides. The isolates originated from hospitals in North America (34%), Europe (23%), Asia (13%), South America (12%), Africa (7%), or Oceania (1%) or were of unknown origin (9%). We developed statistical methods to predict phenotypic resistance from resistance genes for 49 antibiotic-organism combinations, including gentamicin, tobramycin, ciprofloxacin, levofloxacin, trimethoprim-sulfamethoxazole, ertapenem, imipenem, cefazolin, cefepime, cefotaxime, ceftazidime, ceftriaxone, ampicillin, and aztreonam. Average positive predictive values for genotypic prediction of phenotypic resistance were 91% for E. coli, 93% for K. pneumoniae, 87% for P. mirabilis, and 92% for P. aeruginosa across the various antibiotics for this highly resistant cohort of bacterial isolates.


2020 ◽  
Author(s):  
Raymond Mudzana ◽  
Rooyen T Mavenyengwa ◽  
Muchaneta Gudza-Mugabe

Abstract Background: Streptococcus agalacticae (Group B Streptococcus, GBS) is one of the most important causative agents of serious infections among neonates. This study was carried out to identify antibiotic resistance and virulence genes associated with GBS isolated from pregnant women.Methods: A total of 43 GBS isolates were obtained from 420 vaginal samples collected from HIV positive and negative women who were 13-35 weeks pregnant attending Antenatal Care at Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods and molecular identification testing. Antibiotic susceptibility testing was done using the modified Kirby-Bauer method and E-test strips. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes. Data was fed into SPSS 24.0.Results: Nine distinct virulence gene profiles were identified and hly-scpB-bca-rib 37.2% (16/43) was common. The virulence genes identified were namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). High resistance to tetracycline 97.7% (42/43) was reported followed by 72.1% (31/43) cefazolin, 69.8% (30/43) penicillin G, 58.1% (25/43) ampicillin, 55.8% (24/43) clindamycin, 46.5% (20/43) ceftriaxone, 34.9% (15/43) chloramphenicol, and 30.2% (13/43) for both erythromycin and vancomycin using disk diffusion. Antibiotic resistance genes among the resistant and intermediate-resistant isolates showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded 9.3% (4/43).Conclusion: The study showed high prevalence of hly, scpB, bca and rib virulence genes in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. Multi-drug resistance coupled with the recovery of resistant isolates to antimicrobial agents such as penicillins indicates the importance of GBS surveillance and susceptibility tests. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.


2012 ◽  
Vol 57 (No. 4) ◽  
pp. 193-197 ◽  
Author(s):  
H. Momtaz ◽  
E. Rahimi ◽  
S. Moshkelani

This study was carried out to detect the distribution of antibiotic-resistant genes in Escherichia coli isolates from slaughtered commercial chickens in Iran by PCR. The investigated genes included aadA1, tet(A), tet(B), dfrA1, qnrA, aac(3)-IV, sul1, bla<sub>SHV</sub>, bla<sub>CMY</sub>, ere(A), catA1 and cmlA. According to biochemical experiments, 57 isolates from 360 chicken meat samples were recognized as E. coli. The distribution of antibiotic-resistance genes in the E. coli isolates included tet(A) and tet(B) (52.63%), dfrA1, qnrA, catA1 and cmlA (36.84%) and sul1 and ere(A) (47.36%), respectively. Nine strains (15.78%) were resistant to a single antimicrobial agent and 11 strains (19.29%) showed resistance to two antimicrobial agents. Multi-resistance which was defined as resistance to three or more tested agents was found in 64.91% of E. coli strains. The results indicate that all isolates harbour one or more of antibiotic resistance genes and that the PCR technique is a fast, practical and appropriate method for determining the presence of antibiotic-resistance genes. &nbsp;


2003 ◽  
Vol 47 (10) ◽  
pp. 3214-3221 ◽  
Author(s):  
Christine Maynard ◽  
John M. Fairbrother ◽  
Sadjia Bekal ◽  
François Sanschagrin ◽  
Roger C. Levesque ◽  
...  

ABSTRACT A total of 112 Escherichia coli O149:K91 strains isolated from pigs with diarrhea in Quebec, Canada, between 1978 and 2000 were characterized for their genotypic antimicrobial resistance profiles. Tests for resistance to 10 antimicrobial agents were conducted. Resistance to tetracycline and sulfonamides was found to be the most frequent, but resistance to cefotaxime and ceftiofur was absent. An increase in the number of isolates resistant to at least three antimicrobials was observed over time. The distribution of 28 resistance genes covering six antimicrobial families (beta-lactams, aminoglycosides, phenicols, tetracycline, trimethoprim, and sulfonamides) was assessed by colony hybridization. Significant differences in the distributions of tetracycline [tet(A), tet(B), tet(C)], trimethoprim (dhfrI, dhfrV, dhfrXIII), and sulfonamide (sulI, sulII) resistance genes were observed during the study period (1978 to 2000). Sixty percent of the isolates possessed a class 1 integron, illustrating the importance of integrons in the epidemiology of antibiotic resistance in E. coli strains from pigs. Amplification of the integron's variable region resulted in four distinct fragments of 1, 1.3, 1.6, and 1.8 kb, with the 1.6- and 1.8-kb fragments appearing only during the last half of the study period. Examination of linkages among the different resistance genes showed a variety of positive and negative associations. Association analysis of isolates divided into two groups, those isolated between 1978 and 1989 and those isolated between 1990 and 2000, revealed the appearance of new positive resistance gene associations. Our genotypic resistance analyses of ETEC isolates from pigs indicate that many of the antibiotic resistance genes behind phenotypic resistance are not static but, rather, are in a state of flux driven by various selection forces such as the use of specific antimicrobials.


2010 ◽  
Vol 1 (1) ◽  
pp. 75-80 ◽  
Author(s):  
J. Korhonen ◽  
A.H. Van Hoek ◽  
M. Saarela ◽  
G. Huys ◽  
L. Tosi ◽  
...  

We aimed to determine the minimum inhibitory concentrations (MICs) of Lactobacillus rhamnosus (n=75) strains, to study their antibiotic resistance genes with microarray, and to assess the microbiological cut-off values of tested antimicrobial agents. L. rhamnosus strains were tested with agar dilution, broth microdilution and Etest methods for ampicillin, clindamycin, erythromycin, gentamicin, streptomycin, and tetracycline using specific LSM medium. Most of the L. rhamnosus strains were found phenotypically susceptible to all six antibiotics tested. Four of the strains were phenotypically multiresistant, three strains to clindamycin, erythromycin and streptomycin and one strain to streptomycin and tetracycline. Some of the resistant (n=8) and susceptible (n=5) strains were further studied with a microarray method to reveal the antibiotic resistance genes behind the phenotypic resistances. From our experience, we recommend that microbiological cut-off values should be proposed according to the method used.


2021 ◽  
Author(s):  
Farhan Yusuf ◽  
Kimberley Gilbride

Bacterial isolates found in aquatic ecosystems often carry antibiotic resistance genes (ARGs). These ARGs are often found on plasmids and transposons, which allows them to be proliferate throughout bacterial communities via horizontal gene transfer (HGT) causing dissemination of multidrug resistance. The increase in antibiotic resistance has raised concerns about the ability to continue to use these drugs to fight infectious diseases. Novel synthetic antibiotics like ciprofloxacin that are not naturally found in the environment were developed to prevent resistances. However, ciprofloxacin resistance has occurred through chromosomal gene mutations of type 2 topoisomerases or by the acquisition of plasmid-mediated quinolone resistances (PMQR). A particular PMQR, qnr genes, encoding for pentapeptide repeat proteins that confer low levels of quinolone resistance and protect DNA gyrase and topoisomerase IV from antibacterial activity. These qnr genes have been identified globally in both clinical and environmental isolates. The aim of this study was to determine the prevalence of ciprofloxacin-resistant bacteria in aquatic environments in the Greater Toronto Area and the potential dissemination of ciprofloxacin resistance. With the selective pressure of ciprofloxacin, we hypothesize that ciprofloxacin-resistant bacteria (CipR) in the environment may carry PMQR mechanisms while the sensitive population (CipS) would not carry PMQR genes. Isolates were tested for resistance to an additional 12 different antibiotics and identified using Sanger sequencing PCR products of the 16S rRNA gene. To determine which genes are responsible for ciprofloxacin resistance, multiplex PCR of associated qnr genes, qnrA, qnrB, and qnrS, was carried out on 202 environmental isolates. Our data demonstrate a similar prevalence of qnr genes was found in CipR (19%) and CipS (14%) populations suggesting that the presence of these genes was not necessarily correlated with the phenotypic resistance to the antibiotic. Furthermore, ciprofloxacinresistant bacteria were found in all locations at similar frequencies suggesting that resistance genes are widespread and could possibly arise through HGT events. Overall, determining the underlying cause and prevalence of ciprofloxacin resistance could help re-establish the effectiveness of these antimicrobial compounds.


Author(s):  
Srwa Ali Mohammed ◽  
Mohammed Abdul Aziz Hama Ali ◽  
Dereh Lattif Mohammed

Nine isolates of Proteus spp. were isolated from 100 urine samples of renal stone patients which were the urine specimens obtained directly from Sulaimani Teaching Hospital Laboratory, and identified according to the cultural characteristic, morphological, biochemical examination. The antibiotic susceptibility test for all isolates were conducted to nine antimicrobial agents including (Ciprofloxacin (Cip), Tetracycline(TE), Neomycin (N), Gentamicin (CN), Erythromycin (E), Nitrofurantoin (F), Naldixic acid (NA), Imipenem (IPM), Amoxicillin (AX). Plasmid analysis of these isolates showed presence are (22) Kb plasmid. Curing of antibiotic resistance genes by using methanol extracts for leave of Crataegus rhipidophylla  and Adiantum capillus was performed. The minimum inhibitory concentration of these medicinal plants through methanol extracts which were 5000 µg/ml and 1000 µg/ml for Ailanthus altissima and Adiantum capillus respectively. The Sub minimum inhibition concentration (SMIC) was also determined. The results of transformation and curing experiments revealed that SMIC of Ailanthus altissima extract was cured or eliminated plasmid completely, and (SMIC) of Adiantum capillus was cured (CN, E, and AX) resistant genes.


2020 ◽  
Author(s):  
Raymond Mudzana ◽  
Rooyen T Mavenyengwa ◽  
Muchaneta Gudza-Mugabe

Abstract Background: Streptococcus agalacticae (Group B Streptococcus, GBS) is one of the most important causative agents of serious infections among neonates. This study was carried out to identify antibiotic resistance and virulence genes associated with GBS isolated from pregnant women.Methods: A total of 43 GBS isolates were obtained from 420 vaginal samples collected from HIV positive and negative women who were 13-35 weeks pregnant attending Antenatal Care at Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods and molecular identification testing. Antibiotic susceptibility testing was done using the modified Kirby-Bauer method and E-test strips. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes. Data was fed into SPSS 24.0.Results: Nine distinct virulence gene profiles were identified and hly-scpB-bca-rib 37.2% (16/43) was common. The virulence genes identified were namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). High resistance to tetracycline 97.7% (42/43) was reported followed by 72.1% (31/43) cefazolin, 69.8% (30/43) penicillin G, 58.1% (25/43) ampicillin, 55.8% (24/43) clindamycin, 46.5% (20/43) ceftriaxone, 34.9% (15/43) chloramphenicol, and 30.2% (13/43) for both erythromycin and vancomycin using disk diffusion. Antibiotic resistance genes among the resistant and intermediate-resistant isolates showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded 9.3% (4/43).Conclusion: The study showed high prevalence of hly, scpB, bca and rib virulence genes in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. Multi-drug resistance coupled with the recovery of resistant isolates to antimicrobial agents such as penicillins indicates the importance of GBS surveillance and susceptibility tests. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.


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