Antimicrobial resistance studies in staphylococci and streptococci isolated from cows with mastitis in Argentina.

Background: and are the main cause of clinical mastitis in dairy cattle in Argentina, whereas coagulase-negative staphylococci (CNS) and environmental streptococci are the main cause of subclinical mastitis. Bacteria isolated from infected animals show increasing antimicrobial resistance.

Objectives: This study aims to determine the antimicrobial resistance of staphylococci and streptococci isolated from milk with mastitis, and to genotypically characterize the methicillin-resistant (MR) staphylococci.

Antimicrobial resistance in bacterial isolates from companion animals in Buenos Aires, Argentina: 2011-2017 retrospective study.

The widespread use of antimicrobial therapy in companion animals could lead to increased levels of resistance. Monitoring these levels is critical to understand not only the zoonotic threat of resistant bacteria but also the interspecies transmission of resistance mechanisms. However, data on resistance levels in companion animals of urban areas in Latin America are lacking.

Co-occurrence of clinically relevant β-lactamases and MCR-1 encoding genes in Escherichia coli from companion animals in Argentina.

Extended-spectrum β-lactamase (ESBL), plasmid-mediated AmpC (pAmpC) and MCR-1 phosphoethanolamine transferase enzymes have been pointed out as the main plasmid-mediated mechanisms of resistance to third generation cephalosporins (TGC) and colistin, respectively, and are currently considered a major concern both in human and veterinary medicine. Little data on these resistance determinants prevalence in companion animal infections is available. The aim of this study was to determine the resistance profile of Escherichia coli isolated from pet infections, in Argentina, and to characterize the resistance mechanisms to TGC, as well as the presence of the plasmid-borne colistin resistance gene, mcr-1.

First isolation of a methicillin-resistant from bovine mastitis in Argentina.

This research communication describes the first isolation of a methicillin-resistant (MRSA) from cow's mastitic milk in Argentina. Bovine mastitis causes important economic losses in the dairy industry and the most commonly isolated bacteria from bovine mastitis are . The A gene present in MRSA bacteria confers resistance to almost all -lactam antibiotics, the most frequent drugs used in bovine mastitis therapy.

Characterization of Shiga toxin-producing Escherichia coli isolated from ground beef collected in different socioeconomic strata markets in Buenos Aires, Argentina.

Consumption of raw/undercooked ground beef is the most common route of transmission of Shiga toxin-producing E. coli (STEC). The aim of the study was to determine the STEC contamination level of the ground beef samples collected in 36 markets of different socioeconomic strata in Buenos Aires, Argentina, and the characterization of the isolated strains.

The icaA gene in staphylococci from bovine mastitis.

Introduction: Staphylococcus aureus and coagulase-negative staphylococci (CNS) are frequently isolated from cows with mastitis. A main virulence factor of CNS is the ability to adhere and form biofilms. The intercellular gene cluster adhesion (ica) operon is one factor involved in biofilm production although ica-independent factors are also involved.

Synanthropic rodents as possible reservoirs of shigatoxigenic Escherichia coli strains.

Shigatoxigenic Escherichia coli (STEC) strains are worldwide zoonotic pathogen responsible for different cases of human disease including hemolytic uremic syndrome (HUS). Transmission of STEC to humans occurs through the consumption of food and water contaminated by faeces of carriers and by person-to-person contact. The objective of this study was two-fold: (1) to investigate whether synanthropic rodents are possible reservoirs of STEC in the urban area and (2) whether a particular genus out of synanthropic rodent is the principal carrier of STEC.

First isolation in Argentina of a highly virulent Shiga toxin-producing Escherichia coli O145:NM from a domestic cat.

Introduction: Hemolytic uremic syndrome (HUS) is distributed worldwide. In Argentina, more than 450 cases of HUS, mostly sporadic, are reported annually. The main serotype isolated is O157:H7, and among non-O157 STEC, O145:NM is the most frequent strain.