Genes Encoding Aminoglycoside O-Nucleotidyltransferases Are Widely Spread Among Streptomycin Resistant Strains of and .

Thermotolerant species and are actually recognized as the major bacterial agent responsible for food-transmitted gastroenteritis. The most effective antimicrobials against are macrolides and some, but not all aminoglycosides. Among these, susceptibility to streptomycin is reduced by mutations in the ribosomal RPSL protein or by expression of ANT(6)-I aminoglycoside O-nucleotidyltransferases.

Co-occurrence of colistin-resistance genes mcr-1 and mcr-3 among multidrug-resistant Escherichia coli isolated from cattle, Spain, September 2015.

Colistin resistance genes mcr-3 and mcr-1 have been detected in an Escherichia coli isolate from cattle faeces in a Spanish slaughterhouse in 2015. The sequences of both genes hybridised to same plasmid band of ca 250 kb, although colistin resistance was non-mobilisable. The isolate was producing extended-spectrum beta-lactamases and belonged to serotype O9:H10 and sequence type ST533.

Detection of plasmid mediated colistin resistance (MCR-1) in Escherichia coli and Salmonella enterica isolated from poultry and swine in Spain.

Recent findings suggest that use of colistin as a last resort antibiotic is seriously threatened by the rise of a new plasmid mediated mechanism of resistance (MCR-1). This work identifies, for the first time in Southern Europe, the gene mcr-1 in nine strains from farm animals (poultry and swine) corresponding to five Escherichia coli and four Salmonella enterica, among which three belong to serovar Typhimurium and one to Rissen. The MCR-1 was found encoded by a plasmid highly mobilizable by conjugation to the E.

Identification of the main quinolone resistance determinant in Campylobacter jejuni and Campylobacter coli by MAMA-DEG PCR.

Among zoonotic diseases, campylobacteriosis stands out as the major bacterial infection producing human gastroenteritis. Antimicrobial therapy, only recommended in critical cases, is challenged by resistance mechanisms that should be unambiguously detected for achievement of effective treatments. Quinolone (ciprofloxacin) resistance of Campylobacter jejuni and Campylobacter coli, the 2 main Campylobacter detected in humans, is conferred by the mutation gyrA C-257-T, which can be genotyped by several methods that require a previous identification of the pathogen species to circumvent the sequence polymorphism of the gene.

Prevalence of quinolone resistance determinants in non-typhoidal Salmonella isolates from human origin in Extremadura, Spain.

Resistance to the quinolones nalidixic acid (NAL) and ciprofloxacin (CIP) and the occurrence of quinolone resistance determinants have been investigated in 300 non-typhoidal Salmonella from human origin, isolated in the years between 2004 and 2008, in 6 hospitals within Extremadura (Spain). Salmonella Enteritidis was the major serotype found among quinolone-resistant isolates, most of which were clustered by clonal analysis to a single clone, which presented D87 or S83 substitutions in GyrA. Eleven isolates presented the non-classical quinolone resistance phenotype (resistance to CIP and susceptibility to NAL), lacking mutations in the quinolone resistance determinant region of topoisomerase genes.

Co-occurrence of ACSSuT and cephalosporin resistance phenotypes is mediated by int1-associated elements in nontyphoidal Salmonella enterica from human infections in Spain.

A screening of antimicrobial resistance and its genetic determinants has been performed on 300 Salmonella enterica isolates collected during 2004-2008 from human infections in Spain. Salmonella Typhimurium and Salmonella Enteritidis were the major serotypes, which were found with similar frequencies covering 80% of the bacterial collection. Salmonella Typhimurium isolates frequently shared low susceptibility to antimicrobials of the penta-resistance phenotype (ACSSuT) and/or cephalosporin resistance.

Dissemination of antimicrobial-resistant clones of Salmonella enterica among domestic animals, wild animals, and humans.

Non-typhoidal salmonellosis is an important zoonotic disease caused by Salmonella enterica. This work focuses on the identification of Salmonella enterica clonal strains which, presenting a wide distribution potential, express resistance determinants that compromise effectiveness of the antimicrobial therapy. The screening was performed on 506 Salmonella enterica isolates from animals and humans, which were characterized by serovar and phage typing, genome macrorestriction and pulsed-field gel electrophoresis, and detection of phenotypic and genotypic traits for antimicrobial resistance.

Antimicrobial resistance determinants among anaerobic bacteria isolated from footrot.

Antibiotic resistance has been evaluated among 36 Gram negative and anaerobic bacilli (10 Bacteroides, 11 Prevotella, 7 Porphyromonas and 8 Fusobacterium strains) isolated from clinical cases of caprine and ovine footrot (necrotic pododermatitis). The initial analysis on this bacterial consortium evaluates the relationships existing among antimicrobial resistance determinants, phenotype expression and mobilization potential. The Bacteroides strains were generally resistant to penicillins, first-generation cephalosporins, tetracycline and erythromycin, and expressed low level of β-lactamase activity.

Discrimination between Bacteroides, Dichelobacter, Fusobacterium, Porphyromonas and Prevotella isolated from caprine footrot by PCR-RFLP - short communication.

Footrot is widely considered the most severe and most common foot pathology in small ruminants. This study tested the ability of a molecular typing system based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay of the 16S rRNA gene to discriminate between the strict anaerobe genera most commonly isolated from footrot ( Bacteroides, Dichelobacter, Fusobacterium, Porphyromonas and Prevotella ) in goats in Extremadura (Spain), with a view to facilitating identification for diagnostic purposes and thus providing a useful tool for future epidemiological studies. Although the electrophoretic patterns obtained with the enzyme Tru 1I were more readily interpreted, and may thus be the best initial option, results may be confirmed by a second enzyme ( RsaI).

Gene Context and DNA rearrangements in the carbapenemase locus of division II strains of Bacteroides fragilis.

The cfiA gene is clustered in a bicistronic operon encoding an N-acetyltransferase and an O-acetyltransferase related to resistance markers. This genetic context, exclusively found in strains of Bacteroides fragilis division II, has been highly rearranged by the successive integration of two new mobile sequences, a miniature element and ISBf9. Besides that, among the DNA polymorphisms detected in the cfiA locus, only the integration of IS942 at its promoter was a determinant for expression of carbapenemase activity.

Genetic determinants for cfxA expression in Bacteroides strains isolated from human infections.

Objectives: To identify genetic determinants that determine beta-lactamase expression in Bacteroides strains isolated from human infections.

Methods: Beta-lactam susceptibility and beta-lactamase enzyme expression were characterized in selected strains. Beta-lactamase genes and surrounding regions were analysed by PCR, inverse PCR and Southern hybridization.

Penicillin-binding proteins of Bacteroides fragilis and their role in the resistance to imipenem of clinical isolates.

In this study penicillin-binding proteins (PBPs) of Bacteroides fragilis and the resistance mechanisms of this micro-organism to 11 beta-lactam antibiotics were analysed. The study focused on the role of PBP2Bfr and metallo-beta-lactamase in the mechanism of resistance to imipenem. The mechanism of beta-lactam resistance in B.

The use of melatonin as a vaccine agent.

Molecules with immunomodulatory properties determine the magnitude and quality of immune responses specific for the coadministered antigen. Melatonin is considered a biological-response modifier of the immune system with broad application in veterinary medicine. In seasonally-breeding animals, the indolamine is able to improve reproductive performance.

Relationship between penicillin-binding protein patterns and beta-lactamases in clinical isolates of Bacteroides fragilis with different susceptibility to beta-lactam antibiotics.

This study examines the role of the penicillin-binding proteins (PBPs) of Bacteroides fragilis in the mechanism of resistance to different beta-lactam antibiotics. Six of the eight strains used were beta-lactamase-positive by the nitrocefin assay. These strains displayed reduced susceptibility to imipenem (MIC, 2-16 mg l(-1)) and some of them were resistant to the actions of ampicillin, cefuroxime, cephalexin, cefoxitin and piperacillin.