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Zhang X, Guo M, Xie D, Chen Y, Zhang C, Cao Y, Wu Y. Antibiotic resistance of Mycoplasma Synoviae strains isolated in China from 2016 to 2019. BMC Vet Res 2022; 18:1. [PMID: 34980113 PMCID: PMC8722301 DOI: 10.1186/s12917-021-03104-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 12/09/2021] [Indexed: 01/24/2023] Open
Abstract
Background In the past decade, Mycoplasma synoviae (M. synoviae) infection has become widely prevalent in China, has caused serious economic losses and has become one of the most important diseases in the chicken industry. Medication is a general approach for the control of M. synoviae infection, but antibiotics are sometimes ineffective in clinical practice. To investigate the sensitivity of M. synoviae to antimicrobials commonly used in the treatment of M. synoviae infection, the antibiotic susceptibility of 32 M. synoviae strains isolated from China from 2016 to 2019 were determined using the minimum inhibitory concentration (MIC) method. Results All isolates had low MIC values for the combination of lincomycin and spectinomycin, pleuromutilin, and macrolides. However, the M. synoviae isolates displayed variance in MICs for doxycycline hydrochloride with a range of 0.25 to 8 μg/mL, and oxytetracycline hydrochloride with a range of 0.5 to 8 μg/mL. Three and one M. synoviae isolates showed intermediate MIC values to doxycycline hydrochloride and oxytetracycline hydrochloride, respectively. High MIC values for enrofloxacin were detected in all isolates with MICs ranging from 4 to 32 μg/mL. Furthermore, comparison of the parC QRDR identified a mutation at nucleotide position 254 (C254T) resulting in a Thr 85 Ile amino acid change in all M. synoviae isolates and the reference strain ATCC 25204 being resistant to enrofloxacin. Moreover, mutations at Glu 804 Gly and Thr 686 Ala of gyrA QRDR were identified in all M. synoviae isolates and ATCC 25204. The mutation in the QRDR of the parE gene resulted in amino acid changes at positions 197 (Pro to Ser) in 27/32 M. synoviae isolates. Conclusion Three nonsynonymous mutations in gyrA and parE were first identified to be related to enrofloxacin resistance. Our results showed that M. synoviae resistance to enrofloxacin is widespread.
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Affiliation(s)
- Xiaorong Zhang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Mengjiao Guo
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Di Xie
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yang Chen
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Chengcheng Zhang
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Yongzhong Cao
- Joint International Research Laboratory of Agriculture & Agri-Product Safety, Yangzhou University (JIRLAAPS), Yangzhou, 225009, Jiangsu, China
| | - Yantao Wu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Yangzhou University (JIRLAAPS), Yangzhou, 225009, Jiangsu, China.
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Antimicrobial minimum inhibitory concentration of Mycoplasma gallisepticum: a systematic review. J APPL POULTRY RES 2021. [DOI: 10.1016/j.japr.2021.100160] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Chniba I, Boujemaa S, Mardassi BBA, Ben Abdelmoumen Mardassi B. Clonal dissemination of antibiotic resistance among Tunisian Mycoplasma gallisepticum isolates as revealed by gene-targeted sequencing analysis. Avian Dis 2020; 65:446278. [PMID: 33057595 DOI: 10.1637/aviandiseases-d-20-00080r1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 11/05/2022]
Abstract
SummaryTo date, very little is known about avian mycoplasma infections in Tunisia. Mycoplasma gallisepticum is one of the most economically significant pathogen for poultry in Tunisia and worldwide. Based on the paucity of data regarding the genetic profiles and antibacterial behavior of M. gallisepticum strains in Tunisia, the present study was conducted. Genetic typing and phylogenetic relationships of 40 M. gallisepticum strains (20 Tunisian isolates, 19 international strains collection, and S6 reference strain) were investigated by gene-targeted sequencing (GTS) using 4 loci ( pvpA , mgc2 , vlhA and the InterGenic Spacer Region (IGSR) between the 16S and the 23S rRNA genes). GTS reveals 12 STs that were found to spread over 2 clonal complexes (CC) and 5 singletons.Emergence of enrofloxacin and spiramycin resistance among M. gallisepticum local isolates have been revealed using the broth microdilution method. Causal mutations have been identified by sequencing the quinolone-resistance determining region (QRDR) and domain II and V of 23S rRNA as well as the rplD and rplV genes for enrofloxacine- and macrolide-resistant isolates, respectively. The emersion of antibiotic resistance to enrofloxacin and spiramycin has been identified as being related to a distinctive clonal complex formed by 4 different STs (ST2, ST3, ST4 and ST5) which would suggest that this phenotype was clonally disseminated.
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Affiliation(s)
- Imen Chniba
- Group of Mycoplasmas, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, 13, Place Pasteur, BP 74, 1002, Tunis Belvédère, Tunisia
| | - Safa Boujemaa
- Group of Mycoplasmas, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, 13, Place Pasteur, BP 74, 1002, Tunis Belvédère, Tunisia
| | - Boutheina Ben Abdelmoumen Mardassi
- Group of Mycoplasmas, Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development, Institut Pasteur de Tunis, Université de Tunis El Manar, 13, Place Pasteur, BP 74, 1002, Tunis Belvédère, Tunisia
| | - Boutheina Ben Abdelmoumen Mardassi
- Institut Pasteur de Tunis Head of Mycoplasmas Unit Group of Mycoplasmas. Laboratory of Molecular Microbiology, Vaccinology, and Biotechnology Development 13, Place Pasteur, B.P. 74.1002 Tunis, Belvédère TUNISIA Tunis 1002 00216 71844790
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Abstract
Mycoplasmas are intrinsically resistant to antimicrobials targeting the cell wall (fosfomycin, glycopeptides, or β-lactam antibiotics) and to sulfonamides, first-generation quinolones, trimethoprim, polymixins, and rifampicin. The antibiotics most frequently used to control mycoplasmal infections in animals are macrolides and tetracyclines. Lincosamides, fluoroquinolones, pleuromutilins, phenicols, and aminoglycosides can also be active. Standardization of methods used for determination of susceptibility levels is difficult since no quality control strains are available and because of species-specific growth requirements. Reduced susceptibility levels or resistances to several families of antimicrobials have been reported in field isolates of pathogenic Mycoplasma species of major veterinary interest: M. gallisepticum and M. synoviae in poultry; M. hyopneumoniae, M. hyorhinis, and M. hyosynoviae in swine; M. bovis in cattle; and M. agalactiae in small ruminants. The highest resistances are observed for macrolides, followed by tetracyclines. Most strains remain susceptible to fluoroquinolones. Pleuromutilins are the most effective antibiotics in vitro. Resistance frequencies vary according to the Mycoplasma species but also according to the countries or groups of animals from which the samples were taken. Point mutations in the target genes of different antimicrobials have been identified in resistant field isolates, in vitro-selected mutants, or strains reisolated after an experimental infection followed by one or several treatments: DNA-gyrase and topoisomerase IV for fluoroquinolones; 23S rRNA for macrolides, lincosamides, pleuromutilins, and amphenicols; 16S rRNAs for tetracyclines and aminoglycosides. Further work should be carried out to determine and harmonize specific breakpoints for animal mycoplasmas so that in vitro information can be used to provide advice on selection of in vivo treatments.
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Zhang N, Wu Y, Huang Z, Yao L, Zhang L, Cai Q, Shen X, Jiang H, Ding H. The PK-PD Relationship and Resistance Development of Danofloxacin against Mycoplasma gallisepticum in An In Vivo Infection Model. Front Microbiol 2017; 8:926. [PMID: 28611739 PMCID: PMC5447713 DOI: 10.3389/fmicb.2017.00926] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 05/08/2017] [Indexed: 01/30/2023] Open
Abstract
Mycoplasma gallisepticum is the causative agent of chronic respiratory disease (CRD), a prevalent disease of poultry, which is responsible for significant economic losses in farms. Although several antimicrobial agents are currently recommended for the treatment and prevention of M. gallisepticum infections, investigations of M. gallisepticum have been hampered by their fastidious growth requirements and slow growth rate. As such, little work has been conducted concerning the PK/PD relationship and mechanisms of antibiotic resistance between antimicrobials against M. gallisepticum. In the present study, danofloxacin was orally administrated to the infected chickens once daily for 3 days by an established in vivo M. gallisepticum infection model. Not only the concentrations of danofloxacin in plasma and lung tissues were analyzed, but also the counting of viable cells and changes in antimicrobial susceptibility in air sac and lung were determined. The PK and PD data were fitted by WinNonlin to evaluate the PK/PD interactions of danofloxacin against M. gallisepticum. PCR amplification of quinolone resistance-determining regions (QRDRs) and DNA sequencing were performed to identify point mutations in gyrA, gyrB, parC, and parE of the selected resistant mutant strains. In addition, susceptibility of enrofloxacin, ofloxacin, levofloxacin, gatifloxacin, and norfloxacin against these mutant strains were also determined. The PK profiles indicated that danofloxacin concentration in the lung tissues was higher than plasma. Mycoplasmacidal activity was achieved when infected chickens were exposed to danofloxacin at the dose group above 2.5 mg/kg. The ratios of AUC24/MIC (the area under the concentration-time curve over 24 h divided by the MIC) for 2 log10 (CFU) and 3 log10 (CFU) reduction were 31.97 and 97.98 L h/kg, respectively. Substitutions of Ser-83→Arg or Glu-87→Gly in gyrA; Glu-84→Lys in parC were observed in the resistant mutant strains that were selected from the dose group of 1 and 2.5 mg/kg. MICs of danofloxacin, enrofloxacin, ofloxacin, levofloxacin, gatifloxacin, and norfloxacin against the resistant mutant strains with a single mutation in position-83 were higher than that with a single mutation in position-87. These findings suggested that danofloxacin may be therapeutically effective to treat M. gallisepticum infection in chickens if administered at a dosage of 5.5 mg/kg once daily for 3 days.
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Affiliation(s)
- Nan Zhang
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Yuzhi Wu
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Zilong Huang
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Lihua Yao
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Longfei Zhang
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Qinren Cai
- Technical Center for Inspection and Quarantine, Zhuhai Entry-Exit Inspection and Quarantine BureauZhuhai, China
| | - Xiangguang Shen
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Hongxia Jiang
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
| | - Huanzhong Ding
- Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China
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Das A, Guha C, Biswas U, Jana PS, Chatterjee A, Samanta I. Detection of emerging antibiotic resistance in bacteria isolated from subclinical mastitis in cattle in West Bengal. Vet World 2017; 10:517-520. [PMID: 28620255 PMCID: PMC5465765 DOI: 10.14202/vetworld.2017.517-520] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 03/31/2017] [Indexed: 12/28/2022] Open
Abstract
AIM The aim of this work was to detect antibiotic resistance in Gram-negative bacteria isolated from subclinical mastitis in cattle in West Bengal. MATERIALS AND METHODS The milk samples were collected from the cattle suffering with subclinical mastitis in West Bengal. The milk samples were inoculated into the nutrient broth and incubated at 37°C. On the next day, the growth was transferred into nutrient agar and MacConkey agar. All the pure cultures obtained from nutrient agar slant were subjected to Gram-staining and standard biochemical tests. All the bacterial isolates were tested in vitro for their sensitivity to different antibiotics commonly used in veterinary practices. All Gram-negative isolates including positive control were subjected to polymerase chain reaction (PCR) for detection of blaCTX-M, blaTEM, blaSHV, blaVIM, tetA, tetB, tetC, and tetM genes considered for extended-spectrum β-lactamase (ESBL), metallo-β-lactamase, and tetracycline resistance. RESULTS In total, 50 Gram-negative organisms (Escherichia coli, Proteus, Pseudomonas, Klebsiella, and Enterobacter) were isolated from milk samples of subclinical mastitis infected cattle. Among these Gram-negative isolates, 48% (24/50) were found either ESBL producing or tetracycline resistant. Out of total 50 Gram-negative isolates, blaCTX-M was detected in 18 (36%) isolates, and 6 (12%) harbored blaTEM genes in PCR. None of the isolates carried blaSHV genes. Further, in this study, 5 (10%) isolates harbored tet(A) gene, and 8 (16%) isolates carried tet(B) gene. No tet(C) gene was detected from the isolates. CONCLUSION This study showed emerging trend of antibiotic-resistant Gram-negative bacteria associated with subclinical mastitis in cattle in West Bengal, India.
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Affiliation(s)
- Arnab Das
- Animal Resources Development Department, Institute of Animal Health and Veterinary Biologicals, Government of West Bengal, Kolkata, West Bengal, India
| | - Chanchal Guha
- Department of Veterinary Epidemiology and Preventive Medicine, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Ujjwal Biswas
- Department of Veterinary Epidemiology and Preventive Medicine, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Partha Sarathi Jana
- Department of Veterinary Epidemiology and Preventive Medicine, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Amaresh Chatterjee
- Department of Veterinary Epidemiology and Preventive Medicine, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
| | - Indranil Samanta
- Department of Veterinary Microbiology, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, India
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Molecular characterization of acquired enrofloxacin resistance in Mycoplasma synoviae field isolates. Antimicrob Agents Chemother 2013; 57:3072-7. [PMID: 23612192 DOI: 10.1128/aac.00203-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The in vitro activity of enrofloxacin against 73 Mycoplasma synoviae field strains isolated in Israel and Europe was determined by broth microdilution. Decreased susceptibility to enrofloxacin was identified in 59% of strains, with the MICs ranging from 1 to >16 μg/ml. The estimated MIC50 and MIC90 values for enrofloxacin were 2 and 8 μg/ml, respectively. Moreover, this study showed that 92% of recent Israeli field isolates (2009 to 2011) of M. synoviae have MICs of ≥ 2 μg/ml to enrofloxacin. Comparison of the quinolone resistance-determining regions (QRDRs) in M. synoviae isolates revealed a clear correlation between the presence of one of the amino acid substitutions Asp79-Asn, Thr80-Ala/Ile, Ser81-Pro, and Asp84-Asn/Tyr/His of the ParC QRDR and decreased susceptibility to enrofloxacin (MIC, ≥ 1 μg/ml). Amino acid substitutions at positions GyrA 87, GyrB 401/402, and ParE 420/454 were also identified, but there was no clear-cut correlation with susceptibility to enrofloxacin. Comparison of vlhA molecular profiles revealed the presence of 9 different genotypes in the Israeli M. synoviae field isolates and 10 genotypes in the European isolates; only one vlhA genotype (type 4) was identified in both cohorts. Based on results of vlhA molecular typing, several mechanisms for emergence and dissemination of Israeli enrofloxacin-resistant M. synoviae isolates are suggested.
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Lysnyansky I, Gerchman I, Levisohn S, Mikula I, Feberwee A, Ferguson NM, Noormohammadi AH, Spergser J, Windsor HM. Discrepancy between minimal inhibitory concentration to enrofloxacin and mutations present in the quinolone-resistance determining regions of Mycoplasma gallisepticum field strains. Vet Microbiol 2012; 160:222-6. [PMID: 22655973 DOI: 10.1016/j.vetmic.2012.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 04/30/2012] [Accepted: 05/04/2012] [Indexed: 10/28/2022]
Abstract
Molecular characterization of the quinolone-resistance determining regions (QRDRs) of DNA gyrase and topoisomerase IV in 93 Mycoplasma gallisepticum field strains isolated in different geographic regions revealed discrepancies between minimal inhibitory concentration values and presence of amino acid substitutions within the QRDRs of GyrA and ParC in 9/93 (10%) strains. This may delimitate applicability of a gene-based assay to detect fluoroquinolone resistance in this avian pathogen.
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Affiliation(s)
- I Lysnyansky
- Mycoplasma Unit, Kimron Veterinary Institute, Bet Dagan, Israel.
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Gerchman I, Levisohn S, Mikula I, Manso-Silván L, Lysnyansky I. Characterization of in vivo-acquired resistance to macrolides of Mycoplasma gallisepticum strains isolated from poultry. Vet Res 2011; 42:90. [PMID: 21810258 PMCID: PMC3166906 DOI: 10.1186/1297-9716-42-90] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 08/02/2011] [Indexed: 11/25/2022] Open
Abstract
The macrolide class of antibiotics, including tylosin and tilmicosin, is widely used in the veterinary field for prophylaxis and treatment of mycoplasmosis. In vitro susceptibility testing of 50 strains of M. gallisepticum isolated in Israel during the period 1997-2010 revealed that acquired resistance to tylosin as well as to tilmicosin was present in 50% of them. Moreover, 72% (13/18) of the strains isolated from clinical samples since 2006 showed acquired resistance to enrofloxacin, tylosin and tilmicosin. Molecular typing of the field isolates, performed by gene-target sequencing (GTS), detected 13 molecular types (I-XIII). Type II was the predominant type prior to 2006 whereas type X, first detected in 2008, is currently prevalent. All ten type X strains were resistant to both fluoroquinolones and macrolides, suggesting selective pressure leading to clonal dissemination of resistance. However, this was not a unique event since resistant strains with other GTS molecular types were also found. Concurrently, the molecular basis for macrolide resistance in M. gallisepticum was identified. Our results revealed a clear-cut correlation between single point mutations A2058G or A2059G in domain V of the gene encoding 23S rRNA (rrnA, MGA_01) and acquired macrolide resistance in M. gallisepticum. Indeed, all isolates with MIC ≥ 0.63 μg/mL to tylosin and with MIC ≥ 1.25 μg/mL to tilmicosin possess one of these mutations, suggesting an essential role in decreased susceptibility of M. gallisepticum to 16-membered macrolides.
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Affiliation(s)
- Irena Gerchman
- Mycoplasma Unit, Division of Avian and Fish Diseases, Kimron Veterinary Institute, Bet Dagan, 50250, Israel.
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Shimada Y, Deguchi T, Nakane K, Masue T, Yasuda M, Yokoi S, Ito SI, Nakano M, Ito S, Ishiko H. Emergence of clinical strains of Mycoplasma genitalium harbouring alterations in ParC associated with fluoroquinolone resistance. Int J Antimicrob Agents 2010; 36:255-8. [DOI: 10.1016/j.ijantimicag.2010.05.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 05/13/2010] [Accepted: 05/20/2010] [Indexed: 11/15/2022]
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Ghorashi SA, Noormohammadi AH, Markham PF. Differentiation of Mycoplasma gallisepticum strains using PCR and high-resolution melting curve analysis. MICROBIOLOGY-SGM 2009; 156:1019-1029. [PMID: 20035007 DOI: 10.1099/mic.0.031351-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycoplasma gallisepticum (MG) is an economically important pathogen of poultry worldwide, causing chronic respiratory disease in chickens and turkeys. Differentiation of MG strains is critical, especially in countries where poultry flocks are vaccinated with live vaccines. In this study, oligonucleotide primers were designed based on a region preceding the trinucleotide repeat of a member of the vlhA gene family, and amplicons of 145-352 bp were generated from cultures of 10 different MG strains, including the ts-11, F and 6/85 vaccine strains. High-resolution melting (HRM) curve analysis of the resultant amplicons could differentiate all MG strains. Analysis of the nucleotide sequences of the amplicons from each strain revealed that each melting curve profile related to a unique DNA sequence. The HRM curve profiles (for ts-11) remained consistent after at least five passages under laboratory conditions. PCR-HRM curve analysis of 33 DNA extracts derived from respiratory swabs, or mycoplasma cultures grown from respiratory swabs, of ts-11-vaccinated commercial or specific pathogen-free chickens identified all these specimens, according to their sequences, as ts-11. The potential of the PCR-HRM curve analysis was also shown in the genotyping of 30 additional MG isolates from Europe, the USA and Israel. The results presented in this study indicate that PCR followed by HRM curve analysis provides a rapid and robust technique for genotyping of MG isolates/strains using both MG cultures and clinical swabs.
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Affiliation(s)
- Seyed A Ghorashi
- Faculty of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia
| | - Amir H Noormohammadi
- Faculty of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia
| | - Philip F Markham
- Faculty of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia
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Rapid detection of a point mutation in the parC gene associated with decreased susceptibility to fluoroquinolones in Mycoplasma bovis. Antimicrob Agents Chemother 2009; 53:4911-4. [PMID: 19721062 DOI: 10.1128/aac.00703-09] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Comparison of the quinolone resistance-determining regions (QRDRs) in 42 Mycoplasma bovis clinical isolates revealed amino acid substitutions at both GyrA (position 83) and ParC (position 84) in 10/11 enrofloxacin-resistant strains. The mutation present in the parC QRDR was discriminative for enrofloxacin resistance by parC PCR-restriction fragment length polymorphism. Comparison of molecular profiles by insertion sequence typing suggests that the currently prevalent enrofloxacin-resistant M. bovis strain evolved by selection under field conditions from one of the susceptible strains.
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