Isolation of a point mutation associated with altered expression of the CmeABC efflux pump in a multidrug-resistant Campylobacter jejuni population of poultry origin.

The objective of this study was to investigate the antibiotic resistance phenotype of Campylobacter jejuni isolates from a poultry flock of broiler production in Spain. Isolates were characterised by RFLP-PCR of the flaA gene and multilocus sequence typing. Minimum inhibitory concentrations of quinolones, aminoglycosides, β-lactams, tetracyclines, phenicols, macrolides and lincosamides were determined by Etest.

Development of three multiplex PCR assays targeting the 21 most clinically relevant serogroups associated with Shiga toxin-producing E. coli infection in humans.

Escherichia coli serogroups O5, O15, O26, O45, O55, O76, O91, O103, O104, O111, O113, O118, O121, O123, O128, O145, O146, O157, O165, O172, and O177 are the O-antigen forms of the most clinically relevant Shiga toxin-producing E. coli (STEC) serotypes. In this study, three multiplex PCR assays able to specifically detect these 21 serogroups were developed and validated.

Molecular mechanisms of quinolone, macrolide, and tetracycline resistance among Campylobacter isolates from initial stages of broiler production.

The aim of this study was to investigate the resistance mechanisms of quinolones, macrolides and tetracycline in campylobacter isolates from grandparent and parent broiler breeders in Spain. Twenty-six isolates were investigated for quinolone resistance, three isolates for macrolide resistance and 39 for tetracycline resistance. All of the quinolone-resistant isolates possessed the mutation Thr86Ile in the quinolone resistance-determining region of gyrA and one isolate possessed the mutation Pro104Ser.

[Application of restriction fragment length polymorphism-polymerase chain reaction-flaA and resistotype to identify potential undiagnosed outbreaks of campylobacteriosis in Spain].

Introduction: Outbreaks of campylobacteriosis are infrequent and usually involve a low number of patients, although it is estimated that many more remain undiagnosed. The most successful techniques for outbreak investigation in Campylobacter spp. (PFGE, MLST) have the drawback of being laborious and not available in many laboratories.

Dynamics of populations of Campylobacter jejuni in two grandparent broiler breeder farms: persistent vs. transient strains.

The objectives of the study were to characterize and investigate the populations of Campylobacter jejuni in two grandparent broiler breeder farms over four years. Caecal as well as farm environmental samples were obtained. Campylobacter isolates were characterized by macrorestriction profile (SmaI and KpnI-PFGE) and PCR-RFLP of the flaA gene.

Salmonella spp. and Shiga toxin-producing Escherichia coli prevalence in an ocellated lizard (Timon lepidus) research center in Spain.

The aim of this work was to study the epidemiological status of Salmonella spp. and Shiga toxin-producing Escherichia coli (STEC) in an ocellated lizard research center focusing on the risk and hygiene aspects. Fecal and environmental samples were collected and examined for Salmonella spp.

Drinking water as the source of Campylobacter coli infection in grandparent heavy breeders.

The aim of the present study was the molecular identification of a common source of infection of Campylobacter coli in two grandparent breeder farms. Campylobacter jejuni and C. coli were isolated from well water and cloacal swabs from grandparent chickens.

Study of the molecular mechanisms involved in high-level macrolide resistance of Spanish Campylobacter jejuni and Campylobacter coli strains.

Objectives: To investigate the molecular mechanisms involved in the high-level erythromycin resistance of clinical Spanish Campylobacter jejuni and Campylobacter coli strains.

Methods: Overall susceptibilities of 678 C. jejuni and 119 C.

Spread of a multiresistant CTX-M-9-producing Salmonella enterica serotype Virchow phage type 19 in Spain.

The purpose of this study was to survey Salmonella enterica serotype Virchow phage type 19 (S. Virchow PT19) strains submitted to the Spanish National Reference Laboratory for Salmonella (SNRLS) from 2002 to 2006 in order to determine the rate type and genetic background of beta-lactam resistance and to further identify the associated resistances. Ninety-nine S.

Antimicrobial resistance of Salmonella enterica isolates from apparently healthy and clinically ill finishing pigs in Spain.

This study was the first conducted in Spain to evaluate the occurrence of antimicrobial resistance and multi-resistance in Salmonella isolates recovered from finishing pigs from Spanish swine farms distributed over the whole country. For this purpose, 290 Salmonella isolates recovered from apparently healthy finishing pigs in a farm-based cross-sectional study and 192 Salmonella isolates recovered from faecal samples of finishing pigs suffering from diarrhoea were investigated. Resistance to a panel of 17 antimicrobials was determined using a broth microdilution technique.

Salmonella enterica infections in Spanish swine fattening units.

The present study is the first conducted in Spain to estimate the bacteriological herd prevalence of Salmonella enterica in fattening units and to describe the Salmonella serovar diversity on these farms using a sample representative of the entire swine population. For this purpose, 10 faecal samples were collected from 10 different pens containing pigs close to market weight in a total of 232 fattening units. Total sample size was proportionally distributed according to the fattener census in each of the regions of the country and all the samples were examined by culture of 25 g of faecal material.

Salmonella enterica serotype Typhimurium carrying hybrid virulence-resistance plasmids (pUO-StVR): a new multidrug-resistant group endemic in Spain.

The epidemiological impact in Spain of an emerging group of multidrug-resistant Salmonella enterica serotype Typhimurium, characterized by the presence of virulence-resistance hybrid plasmids (termed pUO-StVR) that are related to the S. Typhimurium virulence plasmid pSLT, was evaluated. Adscription to the group was based on detection of the bla(OXA-1) gene (encoding ampicillin resistance) by PCR, and identification of a pUO-StVR plasmid through hybridization with specific probes for virulence (spvC) and resistance (bla(OXA-1)) genes.

[Molecular characterization of the strain causing a shigellosis outbreak in a Madrid school].

Introduction: The aim of this study is to describe a Shigella sonnei outbreak in a school.

Method: An epidemiological inquiry was performed. Stool samples from 5 patients were cultured.

Blind comparison of traditional serotyping with three multiplex PCRs for the identification of Salmonella serotypes.

Salmonella serotypes are defined on the basis of somatic (O) antigens which define the serogroup and flagellar (H) factor antigens, both of which are present in the cell wall of Salmonella. Most Salmonella organisms alternatively express phase-1 or phase-2 flagellar antigens encoded by fliC and fljB genes, respectively. Our group previously published two multiplex PCRs for distinguishing the most common first- and second-phase antigens.

[Description of an outbreak of Campylobacter jejuni gastroenteritis and molecular characterization of the implicated strain].

Introduction: The aim of this study is to describe an outbreak of diarrhea caused by Campylobacter jejuni in a primary school.

Methods: Stool samples from five patients were cultured. Molecular typing of the isolated strains was performed using PCR-RFLP-flaA, PFGE and MLST.

Late detection of a shigellosis outbreak in a school in Madrid.

Even though shigellosis in Spain is rare, an indigenous outbreak is occasionally detected. We describe an outbreak in a school in Madrid caused by person-to-person transmission of Shigella sonnei. After the detection of Shigella sonnei in a stool sample from a 3 year old girl, an investigation at her school was initiated.

Salmonella Derby clonal spread from pork.

The genetic diversity of the Derby serotype of Salmonella enterica in Spain was examined by pulsed-field gel electrophoresis (PFGE). Out of 24 identified PFGE profiles, a major clone was detected in 19% of strains from humans, 52% from food, and 62% from swine. This clone (clone 1) was isolated from pork products, suggesting swine as its source.

[Serotype and phage type distribution of human Salmonella strains isolated in Spain, 1997-2001].

Introduction: Salmonellosis is one of the most frequent causes of gastroenteritis in Spain. Serotyping is the gold standard epidemiological marker for subdividing Salmonella spp. strains.

Multiplex PCR for distinguishing the most common phase-1 flagellar antigens of Salmonella spp.

Most Salmonella serotypes alternatively express either phase-1 or phase-2 flagellar antigens, encoded by the fliC and fljB genes, respectively. Flagellar phase reversal for the identification of both flagellar antigens is not necessary at the genetic level. Variable internal regions of the fliC genes encoding the H:i, H:r, H:l,v, H:e,h, H:z(10), H:b, and H:d antigens have been sequenced; and the specific sites for each antigen in selected Salmonella serotypes have been determined.

Use of AFLP, plasmid typing and phenotyping in a comparative study to assess genetic diversity of Shigella flexneri strains.

Shigella flexneri infections are one of the main causes of acute diarrhoea in Cuba. Twenty strains isolated from sporadic cases in nine different Cuban provinces were characterized. Serotyping, antibiotic-resistance typing, plasmid-typing and AFLP-typing were used to determine their suitability for use in epidemiological studies of S.

Comparison of phenotypic and genotypic markers for characterization of an outbreak of Salmonella serotype Havana in captive raptors.

Aims: To establish a typing method for tracing the epidemic relationship of 16 strains of Salmonella serotype Havana isolated from captive raptors showing no symptomatology and residing in a wildlife hospital in Spain.

Methods And Results: Antimicrobial susceptibility testing, ribotyping, pulsed field gel electrophoresis (PFGE) and amplified fragment length polymorphism (AFLP) methodology were applied. Ten unrelated strains of serotype Havana were included as a control group to provide a basis of for the efficiency of the different markers used.