Antimicrobial susceptibility and quinolone resistance mechanism of Arcobacter butzleri isolates from sewage samples in Spain

An increased number of cases of salmonellosis caused by the rare serotype Mikawasima was noted in the years 2012 and 2013 in the Czech Republic. A potential on-going outbreak caused by this serotype in European countries has also been reported. Altogether 14 human and 1 environmental isolates from the year 2012 and 11 human isolates from the year 2013 from different locations of the Czech Republic were sent to our laboratory for typing. Macrorestriction analysis together with antimicrobial susceptibility testing and PCR for ESBL and plasmid-mediated quinolone resistance detection were performed to compare our isolates. Twenty-one isolates created two very similar clusters and 5 isolates had different profiles. Twenty-five isolates were fully susceptible to all agents used. One isolate showed resistance to 12 microbial agents and possessed blaTEM, blaSHV, blaOXA, blaCTX-M and qnrB genes.

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Antimicrobial Susceptibility and Clonality of Clinical Ureaplasma Isolates in the United States

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00671-16 ◽

2016 ◽

Vol 60 (8) ◽

pp. 4793-4798 ◽

Cited By ~ 18

Author(s):

Javier Fernández ◽

Melissa J. Karau ◽

Scott A. Cunningham ◽

Kerryl E. Greenwood-Quaintance ◽

Robin Patel

Keyword(s):

United States ◽

Antimicrobial Susceptibility ◽

Antimicrobial Agents ◽

Ureaplasma Urealyticum ◽

Resistance Mechanism ◽

The United States ◽

Resistance Mechanisms ◽

Resistant Isolate ◽

Limited Information ◽

Content Type

ABSTRACTUreaplasma urealyticumandUreaplasma parvumare pathogens involved in urogenital tract and intrauterine infections and also in systemic diseases in newborns and immunosuppressed patients. There is limited information on the antimicrobial susceptibility and clonality of these species. In this study, we report the susceptibility of 250 contemporary isolates ofUreaplasma(202U. parvumand 48U. urealyticumisolates) recovered at Mayo Clinic, Rochester, MN. MICs of doxycycline, azithromycin, ciprofloxacin, tetracycline, erythromycin, and levofloxacin were determined by broth microdilution, with MICS of the last three interpreted according to CLSI guidelines. Levofloxacin resistance was found in 6.4% and 5.2% ofU. parvumandU. urealyticumisolates, respectively, while 27.2% and 68.8% of isolates, respectively, showed ciprofloxacin MICs of ≥4 μg/ml. The resistance mechanism of levofloxacin-resistant isolates was due to mutations inparC, with the Ser83Leu substitution being most frequent, followed by Glu87Lys. No macrolide resistance was found among the 250 isolates studied; a singleU. parvumisolate was tetracycline resistant.tet(M) was found in 10U. parvumisolates, including the single tetracycline-resistant isolate, as well as in 9 isolates which had low tetracycline and doxycycline MICs. Multilocus sequence typing (MLST) performed on a selection of 46 isolates showed high diversity within the clinicalUreaplasmaisolates studied, regardless of antimicrobial susceptibility. The present work extends previous knowledge regarding susceptibility to antimicrobial agents, resistance mechanisms, and clonality ofUreaplasmaspecies in the United States.

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Ability of the VITEK 2 Advanced Expert System To Identify β-Lactam Phenotypes in Isolates of Enterobacteriaceae andPseudomonas aeruginosa

Journal of Clinical Microbiology ◽

10.1128/jcm.38.2.570-574.2000 ◽

2000 ◽

Vol 38 (2) ◽

pp. 570-574 ◽

Cited By ~ 39

Author(s):

Christine C. Sanders ◽

Michel Peyret ◽

Ellen Smith Moland ◽

Carole Shubert ◽

Kenneth S. Thomson ◽

...

Keyword(s):

Expert System ◽

Antimicrobial Susceptibility ◽

Resistance Mechanism ◽

Test System ◽

Molecular Techniques ◽

Antimicrobial Susceptibility Test ◽

Accurate Identification ◽

Gram Negative ◽

The Family ◽

Vitek 2

The Advanced Expert System (AES) was used in conjunction with the VITEK 2 automated antimicrobial susceptibility test system to ascertain the β-lactam phenotypes of 196 isolates of the familyEnterobacteriaceae and the species Pseudomonas aeruginosa. These isolates represented a panel of strains that had been collected from laboratories worldwide and whose β-lactam phenotypes had been characterized by biochemical and molecular techniques. The antimicrobial susceptibility of each isolate was determined with the VITEK 2 instrument, and the results were analyzed with the AES to ascertain the β-lactam phenotype. The results were then compared to the β-lactam resistance mechanism determined by biochemical and molecular techniques. Overall, the AES was able to ascertain a β-lactam phenotype for 183 of the 196 (93.4%) isolates tested. For 111 of these 183 (60.7%) isolates, the correct β-lactam phenotype was identified definitively in a single choice by the AES, while for an additional 46 isolates (25.1%), the AES identified the correct β-lactam phenotype provisionally within two or more choices. For the remaining 26 isolates (14.2%), the β-lactam phenotype identified by the AES was incorrect. However, for a number of these isolates, the error was due to remediable problems. These results suggest that the AES is capable of accurate identification of the β-lactam phenotypes of gram-negative isolates and that certain modifications can improve its performance even further.

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Antimicrobial Susceptibility Pattern of Helicobacter heilmannii and Helicobacter ailurogastricus Isolates

Microorganisms ◽

10.3390/microorganisms8060957 ◽

2020 ◽

Vol 8 (6) ◽

pp. 957

Author(s):

Rita Matos ◽

Chloë De Witte ◽

Annemieke Smet ◽

Helena Berlamont ◽

Sofie De Bruyckere ◽

...

Keyword(s):

Antimicrobial Susceptibility ◽

Ribosomal Proteins ◽

Antimicrobial Agents ◽

Acquired Resistance ◽

Resistance Mechanism ◽

Bimodal Distribution ◽

Dilution Method ◽

Nucleotide Polymorphisms ◽

Human Patient ◽

Antimicrobial Susceptibility Pattern

A combined agar and broth dilution method followed by qPCR was used to determine the antimicrobial susceptibility of feline H. heilmannii and H. ailurogastricus isolates. All H. ailurogastricus isolates showed a monomodal distribution of MICs for all the antimicrobial agents tested. For H. heilmannii, a bimodal distribution was observed for azithromycin, enrofloxacin, spectinomycin, and lincomycin. Single nucleotide polymorphisms (SNPs) were found in 50S ribosomal proteins L2 and L3 of the H. heilmannii isolate not belonging to the WT population for azithromycin, and in 30S ribosomal proteins S1, S7, and S12 of the isolate not belonging to the WT population for spectinomycin. The antimicrobial resistance mechanism to enrofloxacin and lincomycin remains unknown (2 and 1 H. heilmannii isolate(s), resp.). Furthermore, H. heilmannii isolates showed higher MICs for neomycin compared to H. ailurogastricus isolates which may be related to the presence of SNPs in several 30S and 50S ribosomal protein encoding genes and ribosomal RNA methyltransferase genes. This study shows that acquired resistance to azithromycin, spectinomycin, enrofloxacin, and lincomycin occasionally occurs in feline H. heilmannii isolates. As pets may constitute a source of infection for humans, this should be kept in mind when dealing with a human patient infected with H. heilmannii.

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Structural Insights into the Quinolone Resistance Mechanism of Mycobacterium tuberculosis DNA Gyrase

PLoS ONE ◽

10.1371/journal.pone.0012245 ◽

2010 ◽

Vol 5 (8) ◽

pp. e12245 ◽

Cited By ~ 82

Author(s):

Jérémie Piton ◽

Stéphanie Petrella ◽

Marc Delarue ◽

Gwénaëlle André-Leroux ◽

Vincent Jarlier ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Resistance Mechanism ◽

Dna Gyrase ◽

Quinolone Resistance ◽

Structural Insights

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Antimicrobial susceptibility and mechanism of quinolone resistance in Campylobacter jejuni strains isolated from diarrheal patients in a hospital in Tokyo

Journal of Infection and Chemotherapy ◽

10.1007/s10156-008-0631-2 ◽

2008 ◽

Vol 14 (5) ◽

pp. 342-348 ◽

Cited By ~ 17

Author(s):

Gulibahaer Bakeli ◽

Kenya Sato ◽

Wakako Kumita ◽

Ryoichi Saito ◽

Emi Ono ◽

...

Keyword(s):

Campylobacter Jejuni ◽

Antimicrobial Susceptibility ◽

Quinolone Resistance

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Molecular Typing and Antimicrobial Susceptibility Profiles of Streptococcus uberis Isolated From Sheep Milk

10.20944/preprints202111.0140.v1 ◽

2021 ◽

Author(s):

Nives Maria Rosa ◽

Ilaria Dupre ◽

Elisa Azara ◽

Carla Maria Longheu ◽

Sebastiana Tola

Keyword(s):

Antimicrobial Resistance ◽

Antimicrobial Susceptibility ◽

Genetic Relatedness ◽

Efflux Pump ◽

Resistance Mechanism ◽

Resistance Rate ◽

Disk Diffusion Test ◽

Sheep Milk ◽

Streptococcus Uberis

Intrammary infections are a major problem for dairy sheep farms, and Streptococcus uberis is one of the main etiological agents of ovine mastitis. Surveys on antimicrobial resistance are still limited in sheep and characterization of isolates is important for acquiring information on resistance and for optimizing therapy. In this study, a sampling of 124 S. uberis isolates collected in Sardinia (Italy) from sheep milk was analysed by multilocus-sequence typing (MLST) and pulsed field gel electrophoresis (PFGE) for genetic relatedness. All isolates were also subjected to antimicrobial susceptibility analysis by the disk diffusion test using a panel of 14 antimicrobials. Resistance genes were detected by PCR assays. MLST analysis revealed that the isolates were grouped into 86 sequence types (STs), of which 73 were new genotypes, indicating a highly diverse population of S. uberis. The most frequently detected lineage was the clonal complex (CC)143, although representing only 13.7% of all characterized isolates. A high level of heterogeneity was also observed among the SmaI PFGE profiles, with 121 unique patterns. Almost all (96.8%) isolates were resistant to at least one antimicrobial, while all exhibited phenotypic susceptibility to oxacillin, amoxicillin-clavulanic acid and ceftiofur. Of the antimicrobials tested, the highest resistance rate was found against streptomycin (93.5%), kanamycin (79.8%) and gentamicin (64.5%), followed by novobiocin (25%) and tetracycline-TE (19.3%). Seventy-four (59.7%) isolates were simultaneously resistant to all aminoglycosides tested. Seventeen isolates (13.7%) exhibited multidrug resistance. All aminoglycosides-resistant isolates were PCR negative for aad-6 and aphA-3’ genes. Among the TE-resistant isolates, the tetM gene was predominant, indicating that the resistance mechanism is mainly mediated by the protection of ribosomes and not through the efflux pump. Three isolates were resistant to erythromycin, and two of them harboured the ermB gene. This is the first study reporting a detailed characterization of the S. uberis strains circulating in Sardinian sheep. Further investigations will be needed to understand the relationships between S. uberis genotypes, mastitis severity, and intra-mammary infection dynamics in the flock, as well as to monitor the evolution of antimicrobial resistance.

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Characterization of Erysipelothrix rhusiopathiae Isolates from Diseased Pigs in 15 Chinese Provinces from 2012 to 2018

Microorganisms ◽

10.3390/microorganisms9122615 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2615

Author(s):

Chao Wu ◽

Changjie Lv ◽

Ya Zhao ◽

Weifeng Zhu ◽

Liang Liu ◽

...

Keyword(s):

Antimicrobial Susceptibility ◽

Multilocus Sequence Typing ◽

Resistance Mechanism ◽

Erysipelothrix Rhusiopathiae ◽

Gyra Gene ◽

E Coli ◽

Resistant Strains ◽

Clinical Prevention ◽

Swine Erysipelas ◽

And Control

Erysipelothrix rhusiopathiae can cause erysipelas in animals and erysipeloid in humans. Since its recurrence in 2012, swine erysipelas has caused serious losses within the pig industry in China. The aim of this study was to perform multilocus sequence typing and understand the virulence and antimicrobial susceptibility of E. rhusiopathiae isolates in China. Multilocus sequence typing (MLST) of a total of 120 strains was performed, and as a result, three different sequence types were identified, of which ST48 was the main one. Five isolates of each MLST type were randomly selected to be used to challenge mice. ST48 was associated with a higher virulence. Antimicrobial susceptibility was tested using a microdilution technique and, to analyze the resistance mechanism, six strains were selected for genome sequencing. A comparison of the six genomes indicated the presence of a suspected macrolide resistance gene, namely, Erm(A)-like, in erythromycin-resistant strains, which increased the minimum inhibitory concentration (MIC) of erythromycin against E. coli C600 at least four-fold. In addition, three mutations (gyrA86T-I, gyrA90D-N, and parC81S-I) were observed in the quinolone resistance-determining regions (QRDRs) of gyrA and parC in quinolone-resistant strains. After the gyrA gene with the 86T-I mutation or the parC gene with the 81S-I mutation was transfected into E. coli C600, the MIC of enrofloxacin against this strain increased at least two-fold. Our findings provide a theoretical basis for developing antibacterial drugs and may contribute to the clinical prevention and control of E. rhusiopathiae.

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