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1.
Sci Rep ; 8(1): 2393, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29403020

RESUMO

Campylobacter hyointestinalis is a member of an emerging group of zoonotic Campylobacter spp. that are increasingly identified in both gastric and non-gastric disease in humans. Here, we discovered C. hyointestinalis in three separate classes of New Zealand ruminant livestock; cattle, sheep and deer. To investigate the relevance of these findings we performed a systematic literature review on global C. hyointestinalis epidemiology and used comparative genomics to better understand and classify members of the species. We found that C. hyointestinalis subspecies hyointestinalis has an open pangenome, with accessory gene contents involved in many essential processes such as metabolism, virulence and defence. We observed that horizontal gene transfer is likely to have played an overwhelming role in species diversification, favouring a public-goods-like mechanism of gene 'acquisition and resampling' over a tree-of-life-like vertical inheritance model of evolution. As a result, simplistic gene-based inferences of taxonomy by similarity are likely to be misleading. Such genomic plasticity will also mean that local evolutionary histories likely influence key species characteristics, such as host-association and virulence. This may help explain geographical differences in reported C. hyointestinalis epidemiology and limits what characteristics may be generalised, requiring further genomic studies of C. hyointestinalis in areas where it causes disease.


Assuntos
Infecções por Campylobacter/veterinária , Campylobacter hyointestinalis/classificação , Campylobacter hyointestinalis/genética , Variação Genética , Filogenia , Zoonoses/epidemiologia , Zoonoses/microbiologia , Animais , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter hyointestinalis/isolamento & purificação , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Cervos , Evolução Molecular , Transferência Genética Horizontal , Genoma Bacteriano , Genômica , Nova Zelândia/epidemiologia , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia
2.
J Vet Med Sci ; 79(2): 336-342, 2017 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-27916784

RESUMO

Campylobacter hyointestinalis is considered as an emerging zoonotic pathogen. We have recently identified two types of cytolethal distending toxin (cdt) gene in C. hyointestinalis and designated them as Chcdt-I and Chcdt-II. In this study, we developed a PCR-restriction fragment length polymorphism (RFLP) assay that can differentiate Chcdt-I from Chcdt-II. When the PCR-RFLP assay was applied to 17 other Campylobacter strains and 25 non-Campylobacter strains, PCR products were not obtained irrespective of their cdt gene-possession, indicating that the specificity of the PCR-RFLP assay was 100%. In contrast, when the PCR-RFLP assay was applied to 35 C. hyointestinalis strains including 23 analyzed in the previous study and 12 newly isolated from pigs and bovines, all of them showed the presence of cdt genes. Furthermore, a restriction digest by EcoT14-I revealed that 29 strains contained both Chcdt-I and Chcdt-II and 6 strains contained only Chcdt-II, showing 100% sensitivity. Unexpectedly, however, PCR products obtained from 7 C. hyointestinalis strains were not completely digested by EcoT14-I. Nucleotide sequence analysis revealed that the undigested PCR product was homologous to cdtB but not to Chcdt-IB or Chcdt-IIB, indicating the presence of another cdt gene-variant. Then, we further digested the PCR products with DdeI in addition to EcoT14-I, showing that all three cdt genes, including a possible new Chcdt variant, could be clearly differentiated. Thus, the PCR-RFLP assay developed in this study is a valuable tool for evaluating the Chcdt gene-profile of bacteria.


Assuntos
Toxinas Bacterianas/genética , Campylobacter hyointestinalis/genética , Genes Bacterianos/genética , Polimorfismo de Fragmento de Restrição/genética , Animais , Infecções por Campylobacter/diagnóstico , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/veterinária , DNA Bacteriano/genética , Humanos , Reação em Cadeia da Polimerase/métodos
3.
Jpn J Infect Dis ; 69(3): 256-8, 2016 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-26255737

RESUMO

In this study, we devised a multiplex PCR assay based on the gene of cytolethal distending toxin (cdt) B subunit to simultaneously detect and discriminate Campylobacter jejuni, C. fetus, C. coli, C. upsaliensis, C. hyointestinalis, and C. lari. Species-specific PCR products were successfully obtained from all 38 C. jejuni, 12 C. fetus, 39 C. coli, 22 C. upsaliensis, 24 C. hyointestinalis, and 7 C. lari strains tested. On the other hand, no specific PCR products were obtained from other campylobacters and bacterial species tested (41 strains in total). The proposed multiplex PCR assay is a valuable tool for detection and descrimination of 6 major Campylobacter species, that are associated with gastrointestinal diseases in humans.


Assuntos
Infecções por Campylobacter/diagnóstico , Campylobacter coli/genética , Campylobacter fetus/genética , Campylobacter hyointestinalis/genética , Campylobacter jejuni/genética , Campylobacter lari/genética , Campylobacter upsaliensis/genética , Reação em Cadeia da Polimerase Multiplex/métodos , Toxinas Bacterianas/genética , Infecções por Campylobacter/microbiologia , Campylobacter coli/isolamento & purificação , Campylobacter fetus/isolamento & purificação , Campylobacter hyointestinalis/isolamento & purificação , Campylobacter jejuni/isolamento & purificação , Campylobacter lari/isolamento & purificação , Campylobacter upsaliensis/isolamento & purificação , Primers do DNA/química , DNA Bacteriano/genética , Diagnóstico Diferencial , Humanos , Sensibilidade e Especificidade , Especificidade da Espécie
5.
Infect Immun ; 83(11): 4304-13, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26283337

RESUMO

Campylobacter hyointestinalis isolated from swine with proliferative enteritis often is considered to be pathogenic. While the precise virulence mechanisms of this species remain unclear, we have recently identified a cytolethal distending toxin (cdt) gene cluster in C. hyointestinalis isolated from a patient with diarrhea (W. Samosornsuk et al., J Med Microbiol, 27 July 2015, http://dx.doi.org/10.1099/jmm.0.000145). However, the sequences of the cdt genes in C. hyointestinalis were found to be significantly different and the gene products are immunologically distinct from those of other Campylobacter species. In this study, we demonstrate the presence of a second variant of the cdt gene cluster in C. hyointestinalis, designated cdt-II, while the former is named cdt-I. Sequencing of the cdt-II gene cluster and deduced amino acid sequences revealed that homologies between the subunits CdtA, CdtB, and CdtC of ChCDT-I and ChCDT-II are 25.0, 56.0, and 24.8%, respectively. Furthermore, the CdtB subunit of ChCDT-II was found to be immunologically unrelated to that of ChCDT-I by Ouchterlony double gel diffusion test. Recombinant ChCDT-II also induced cell distention and death of HeLa cells by blocking the cell cycle at G2/M phase. Interestingly, the cdt-II genes were detected in all 23 animal isolates and in 1 human isolate of C. hyointestinalis, and 21 of these strains carried both cdt-I and cdt-II gene clusters. Altogether, our results indicate that ChCDT-II is an important virulence factor of C. hyointestinalis in animals.


Assuntos
Toxinas Bacterianas/metabolismo , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/veterinária , Campylobacter hyointestinalis/metabolismo , Doenças dos Suínos/microbiologia , Animais , Toxinas Bacterianas/farmacologia , Infecções por Campylobacter/fisiopatologia , Campylobacter hyointestinalis/genética , Campylobacter hyointestinalis/isolamento & purificação , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Dados de Sequência Molecular , Suínos
6.
J Med Microbiol ; 64(10): 1124-1134, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26220191

RESUMO

Increasing numbers of Campylobacter hyointestinalis have been isolated from humans and animals with gastroenteritis, although the virulence mechanism of this species remains largely unknown. Here, we show that C. hyointestinalis isolated from a patient with diarrhoea in Thailand produced a novel variant of cytolethal distending toxin (CDT). Sequencing of a 13 965 bp genomic region of C. hyointestinalis carrying the genes coding for Ch-CDT revealed three ORFs of 798, 804 and 537 bp, which code for the Ch-CdtA, Ch-CdtB and Ch-CdtC subunits, respectively. The deduced amino acid sequence of Ch-CdtA showed ∼38.9 % homology with the CdtA of Campylobacter coli, but sequences of Ch-CdtB and Ch-CdtC were homologous to CdtB (65.7 %) and CdtC (33.1 %) of Campylobacter upsaliensis, respectively. Filter-sterilized sonic lysate of C. hyointestinalis demonstrated distension and death of HeLa cells by arresting the cell cycle at the G(2)/M phase and phosphorylation of host histone H2AX, a sensitive marker of DNA double-strand breaks. Rabbit antiserum raised against recombinant Ch-CdtB was not reactive against the recombinant CdtB protein of Campylobacter jejuni. A reconstituted Ch-CDT holotoxin prepared using each of the recombinant subunit proteins demonstrated distension and death of HeLa cells, suggesting that the C. hyointestinalis isolate indeed produced functionally active Ch-CDT. Furthermore, the immunological distinctiveness of the Ch-CDT produced by C. hyointestinalis and the increasing prevalence of the species in patients and animals with gastroenteritis suggest that this species may be an important emerging zoonotic pathogen.


Assuntos
Toxinas Bacterianas/genética , Toxinas Bacterianas/toxicidade , Infecções por Campylobacter/microbiologia , Campylobacter hyointestinalis/genética , Campylobacter hyointestinalis/isolamento & purificação , Diarreia/microbiologia , Sobrevivência Celular/efeitos dos fármacos , DNA Bacteriano/química , DNA Bacteriano/genética , Células Epiteliais/efeitos dos fármacos , Células HeLa , Humanos , Masculino , Dados de Sequência Molecular , Fases de Leitura Aberta , Análise de Sequência de DNA , Tailândia
7.
J Dairy Sci ; 96(5): 2801-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23453517

RESUMO

The objectives of this study were to investigate the presence of Campylobacter spp. and Arcobacter spp. in dairy herds authorized for the production and sale of raw milk and in a water buffalo dairy farm, and to test the antimicrobial susceptibility of the isolates. A total of 196 in-line milk filters were collected from 14 dairy farms (13 bovine and 1 water buffalo) for detection of Campylobacter spp. and Arcobacter spp. by microbiological culture. For each farm investigated, 1 isolate for each Campylobacter and Arcobacter species isolated was tested using the Etest method (AB Biodisk, Solna, Sweden) to evaluate the susceptibility to ciprofloxacin, tetracycline, chloramphenicol, ampicillin, erythromycin, and gentamicin. A total of 52 isolates were detected in 49 milk filters in 12 farms (85.7%) out of 14 and the isolates were identified as Campylobacter jejuni (6), Campylobacter hyointestinalis ssp. hyointestinalis (8), Campylobacter concisus (1), Campylobacter fetus ssp. fetus (1), Arcobacter butzleri (22), and Arcobacter cryaerophilus (14). The small number of isolates tested for antimicrobial susceptibility precludes any epidemiological consideration but highlights that all Campylobacter isolates were susceptible to macrolides, which are the first-choice drugs for the treatment of campylobacteriosis, and that resistance to fluoroquinolones and tetracycline was detected; for Arcobacter isolates, resistance to ampicillin and chloramphenicol was detected. The sale of raw milk for human consumption by self-service automatic vending machines has been allowed in Italy since 2004 and the presence of C. jejuni in in-line milk filters confirms that raw milk consumption is a significant risk factor for human infection. The high occurrence of emerging Campylobacter spp. and Arcobacter spp. discovered in dairy farms authorized for production and sale of raw milk represents an emerging hazard for human health.


Assuntos
Arcobacter/isolamento & purificação , Campylobacter/isolamento & purificação , Leite/microbiologia , Criação de Animais Domésticos/normas , Animais , Antibacterianos/farmacologia , Arcobacter/efeitos dos fármacos , Búfalos/microbiologia , Campylobacter/efeitos dos fármacos , Campylobacter fetus/efeitos dos fármacos , Campylobacter fetus/isolamento & purificação , Campylobacter hyointestinalis/efeitos dos fármacos , Campylobacter hyointestinalis/isolamento & purificação , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/isolamento & purificação , Feminino , Itália , Testes de Sensibilidade Microbiana
8.
Dig Liver Dis ; 43(1): 23-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20483675

RESUMO

BACKGROUND: Upper gastrointestinal endoscopically biopsied specimens are usually sent for the diagnosis of Helicobacter pylori infection. The study aimed to determine the relationship between the origin of positive Giemsa staining and the grade of gastritis based on the updated Sydney system. METHODS: Gastric biopsy specimens taken at the lesser curvature and greater curvature sides of the corpus and greater curvature side of the antrum were stained with H&E, Giemsa, anti-East Asian-specific antibody and anti-H. pylori antibody stains. Pyrosequencing analysis was performed in cases that showed discrepancy between the Giemsa and anti-H. pylori antibody staining. RESULTS: Seventy-two out of 150 cases (48%) stained positive for anti-H. pylori antibody, of which 68 (94.4%) stained positive for anti-East Asian-specific antibody stain. Twelve of the 20 cases with discrepant results for Giemsa and anti-H. pylori antibody stains exhibited Campylobacter hyointestinalis infection. The grades of neutrophil activity (p<0.001) and chronic inflammation (p<0.001) were lower for Campylobacter infection than for East Asian CagA H. pylori-related infection. CONCLUSION: C. hyointestinalis is the most common cause of non-H. pylori-related Giemsa positive infection, and is associated with lower grades of neutrophil activity and chronic inflammation than East Asian CagA H. pylori-related infection.


Assuntos
Corantes Azur , Infecções por Campylobacter/patologia , Campylobacter hyointestinalis/isolamento & purificação , Gastrite/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/isolamento & purificação , Estômago/microbiologia , Adulto , Idoso , Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Biópsia , Campylobacter hyointestinalis/genética , Campylobacter hyointestinalis/imunologia , Distribuição de Qui-Quadrado , Reações Falso-Positivas , Feminino , Mucosa Gástrica/patologia , Gastrite/patologia , Helicobacter pylori/genética , Helicobacter pylori/imunologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Prospectivos , República da Coreia , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Estômago/patologia
9.
Lett Appl Microbiol ; 44(5): 544-9, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17451523

RESUMO

AIMS: To examine the influence of pH of triple sugar iron (TSI) agar medium on the detection of hydrogen sulfide (H(2)S) production in Campylobacter hyointestinalis ssp. hyointestinalis (CHH). METHODS AND RESULTS: TSI medium was adjusted by the addition in HCl or NaOH to cover a pH 6.0-9.0. One loopful of bacterial growth of CHH strain ATCC 35217 was inoculated into each different pH medium, and incubated at 37 degrees C under micro-aerobic conditions. The H(2)S production was not detectable even after incubation for 72 h in acidic medium pH; however, TSI with alkaline pH (8.0-9.0) allowed detection as early as 3 h of incubation. A total of 20 CHH strains from various animal sources were examined for the detection of H(2)S production in TSI medium with pH 9.0. The H(2)S was detected in all the strains examined within 12 h, and the judgment was unambiguous. CONCLUSION: The results showed that the detection of H(2)S production by CHH was influenced by medium pH, and TSI with alkaline condition is highly sensitive. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of the present study suggest that TSI medium with alkaline pH contributes to fast detection and led to unambiguous judgment of H(2)S production by CHH.


Assuntos
Campylobacter hyointestinalis/metabolismo , Sulfeto de Hidrogênio/metabolismo , Campylobacter hyointestinalis/química , Meios de Cultura , Sulfeto de Hidrogênio/análise , Concentração de Íons de Hidrogênio
10.
Appl Environ Microbiol ; 73(10): 3232-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17369335

RESUMO

The study investigated the prevalence of Campylobacter spp. in Finnish cattle at slaughter and carcass contamination after slaughter. During the period January to December 2003, bovine rectal fecal samples (n=952) and carcass surface samples (n=948) from 12 out of 15 Finnish slaughterhouses were examined. In total, campylobacters were detected in 31.1% of fecal samples and in 3.5% of carcass surface samples. Campylobacter jejuni was isolated from 19.5%, Campylobacter coli from 2.2%, and presumptive Campylobacter hyointestinalis from 10.8% of fecal samples. Campylobacters were detected in 4.4% and 37.4% of the fecal samples examined both by direct culture and by enrichment (n=730), respectively, suggesting a low level of campylobacters in the intestinal content. A slightly increasing trend was observed in the overall prevalence of campylobacters towards the end of summer and autumn. Seventeen different serotypes were detected among the fecal C. jejuni isolates using a set of 25 commercial antisera for serotyping heat-stable antigens (Penner) of C. jejuni by passive hemagglutination. The predominant serotypes, Pen2 and Pen4-complex, were isolated from 52% of the fecal samples. Subtyping by pulsed-field gel electrophoresis (SmaI) yielded 56 and 20 subtypes out of 330 fecal and 70 carcass C. jejuni isolates, respectively. MICs of ampicillin, enrofloxacin, erythromycin, gentamicin, nalidixic acid, and oxytetracycline for 187 C. jejuni isolates were determined using a commercial broth microdilution method. Sixteen (9%) of the isolates were resistant to at least one of the antimicrobials tested. Resistance to nalidixic acid was most commonly detected (6%). No multiresistance was observed.


Assuntos
Antibacterianos/farmacologia , Infecções por Campylobacter/veterinária , Campylobacter coli/isolamento & purificação , Campylobacter hyointestinalis/isolamento & purificação , Campylobacter jejuni/isolamento & purificação , Doenças dos Bovinos/microbiologia , Matadouros , Animais , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter coli/efeitos dos fármacos , Campylobacter hyointestinalis/efeitos dos fármacos , Campylobacter jejuni/classificação , Campylobacter jejuni/efeitos dos fármacos , Bovinos , Doenças dos Bovinos/epidemiologia , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Fezes/microbiologia , Finlândia/epidemiologia , Genótipo , Testes de Hemaglutinação , Testes de Sensibilidade Microbiana , Prevalência , Reto/microbiologia , Estações do Ano , Sorotipagem
11.
Plasmid ; 57(2): 108-17, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17064774

RESUMO

Three small, cryptic plasmids from the multi-drug-resistant (MDR) Campylobacter coli strain RM2228 and one small, cryptic plasmid from the MDR Campylobacter jejuni strain RM1170 were sequenced and characterized. pCC2228-1 has some similarity to Firmicutes RepL family plasmids that replicate via a rolling-circle mechanism. pCC2228-2 is a theta-replicating, iteron-containing plasmid (ICP) that is a member of the same incompatibility (Inc) group as previously described Campylobacter shuttle vectors. The other two ICPs, pCC2228-3 and pCJ1170, represent a second novel Inc group. Comparison of the four plasmids described in this study with other characterized plasmids from C. jejuni, C. coli, C. lari, and C. hyointestinalis suggests that cryptic plasmids in Campylobacter may be classified into as many as nine Inc groups. The plasmids characterized in this study have several unique features suitable for the construction of novel Campylobacter shuttle vectors, e.g., small size, absence of many common multiple-cloning site restriction sites, and Inc groups not represented by current Campylobacter shuttle plasmids. Thus, these plasmids may be used to construct a new generation of Campylobacter shuttle vectors that would permit transformation of environmental Campylobacter isolates with an existing repertoire of native plasmids.


Assuntos
Campylobacter/genética , Plasmídeos/genética , Plasmídeos/isolamento & purificação , Proteínas de Bactérias , Composição de Bases , Sequência de Bases , Campylobacter coli/genética , Campylobacter hyointestinalis/genética , Campylobacter jejuni/genética , Campylobacter lari/genética , Resistência Microbiana a Medicamentos/genética , Dosagem de Genes , Genes Bacterianos , Dados de Sequência Molecular , Filogenia , Plasmídeos/classificação , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
12.
Appl Environ Microbiol ; 71(7): 3872-81, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16000800

RESUMO

The influence of antimicrobial agents on the development of antimicrobial resistance (AMR) in Campylobacter isolates recovered from 300 beef cattle maintained in an experimental feedlot was monitored over a 315-day period (11 sample times). Groups of calves were assigned to one of the following antimicrobial treatments: chlortetracycline and sulfamethazine (CS), chlortetracycline alone (Ct), virginiamycin, monensin, tylosin phosphate, and no antimicrobial agent (i.e., control treatment). In total, 3,283 fecal samples were processed for campylobacters over the course of the experiment. Of the 2,052 bacterial isolates recovered, 92% were Campylobacter (1,518 were Campylobacter hyointestinalis and 380 were C. jejuni). None of the antimicrobial treatments decreased the isolation frequency of C. jejuni relative to the control treatment. In contrast, C. hyointestinalis was isolated less frequently from animals treated with CS and to a lesser extent from animals treated with Ct. The majority (> or =94%) of C. jejuni isolates were sensitive to ampicillin, erythromycin, and ciprofloxacin, but more isolates with resistance to tetracycline were recovered from animals fed Ct. All of the 1,500 isolates of C. hyointestinalis examined were sensitive to ciprofloxacin. In contrast, 11%, 10%, and 1% of these isolates were resistant to tetracycline, erythromycin, and ampicillin, respectively. The number of animals from which C. hyointestinalis isolates with resistance to erythromycin and tetracycline were recovered differed among the antimicrobial treatments. Only Ct administration increased the carriage rates of erythromycin-resistant isolates of C. hyointestinalis, and the inclusion of CS in the diet increased the number of animals from which tetracycline-resistant isolates were recovered. The majority of C. hyointestinalis isolates with resistance to tetracycline were obtained from cohorts within a single pen, and most of these isolates were recovered from cattle during feeding of a forage-based diet as opposed to a grain-based diet. The findings of this study show that the subtherapeutic administration of tetracycline, alone and in combination with sulfamethazine, to feedlot cattle can select for the carriage of resistant strains of Campylobacter species. Considering the widespread use of in-feed antimicrobial agents and the high frequency of beef cattle that shed campylobacters, the development of AMR should be monitored as part of an on-going surveillance program.


Assuntos
Antibacterianos/administração & dosagem , Infecções por Campylobacter/veterinária , Campylobacter hyointestinalis/efeitos dos fármacos , Campylobacter jejuni/efeitos dos fármacos , Doenças dos Bovinos/epidemiologia , Farmacorresistência Bacteriana , Animais , Antibacterianos/farmacologia , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Campylobacter hyointestinalis/classificação , Campylobacter hyointestinalis/genética , Campylobacter hyointestinalis/isolamento & purificação , Campylobacter jejuni/classificação , Campylobacter jejuni/genética , Campylobacter jejuni/isolamento & purificação , Bovinos , Doenças dos Bovinos/microbiologia , Masculino , Carne/microbiologia , Testes de Sensibilidade Microbiana , Prevalência
13.
J Antimicrob Chemother ; 55(2): 182-7, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15649999

RESUMO

OBJECTIVES: To study the susceptibility of Campylobacter hyointestinalis subsp. hyointestinalis to several antimicrobial agents and to investigate the mechanisms of nalidixic acid and ciprofloxacin resistance. METHODS: The disc diffusion method was employed to study the susceptibility of 49 C. hyointestinalis subsp. hyointestinalis strains of reindeer and bovine origin to 12 different antimicrobial agents. In addition, the MICs of nalidixic acid and ciprofloxacin were determined. The nucleotide sequence of a 270 bp fragment of the gyrA gene was determined in ciprofloxacin-susceptible and -resistant strains. The effect of a multidrug efflux pump inhibitor Phe-Arg-beta-naphthylamide (PA beta N) on the MICs of ciprofloxacin and nalidixic acid was also studied. RESULTS: The only decreased susceptibility for antimicrobial agents of this study was observed for sulphonamide compound and streptomycin (24% and 32% of the strains, respectively), and this phenomenon was observed exclusively in the bovine strains. In sequence studies, a Thr-86-->Ile change was found in strains with MICs of ciprofloxacin of > or = 64 mg/L, but this mutation was absent in strains with lower resistance levels. The use of PA beta N did not affect the MIC of ciprofloxacin but decreased the MIC of nalidixic acid 2-4-fold. CONCLUSIONS: The Finnish C. hyointestinalis subsp. hyointestinalis strains are susceptible to a majority of the antimicrobials of veterinary importance. The mechanism of ciprofloxacin resistance at lower levels (< or = 32 mg/L) is not associated with a specific mutation in the quinolone resistance-determining region of the gyrA gene. Finally, there are distinct differences in the mechanisms of ciprofloxacin resistance compared with nalidixic acid resistance within the studied species.


Assuntos
Campylobacter hyointestinalis/efeitos dos fármacos , Ciprofloxacino/farmacologia , Resistência Microbiana a Medicamentos/fisiologia , Ácido Nalidíxico/farmacologia , Animais , Campylobacter hyointestinalis/isolamento & purificação , Campylobacter hyointestinalis/fisiologia , Bovinos , Testes de Sensibilidade Microbiana/estatística & dados numéricos , Quinolonas/farmacologia , Rena
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