Calidad microbiológica del agua utilizada en establecimientos lecheros de la zona de Villa María (Córdoba) Microbiological quality of the water used in a random sample from dairy farms in Córdoba, Argentina

Se evaluó la calidad bacteriológica del agua de pozo y del agua de lavado en una muestra aleatoria de 50 tambos distribuidos en la cuenca lechera de Villa María (Córdoba), Argentina. La visita a los tambos se realizó en 2007. Un 46 % y un 24 % de los tambos presentaron recuentos de aerobios mesófilos superiores a 500 UFC/ml en el agua de lavado y en el agua de pozo, respectivamente. En un 20 % de los establecimientos se aisló Escherichia coli de ambas fuentes de agua. Pseudomonas aeruginosa registró una alta frecuencia de aislamiento en el agua de pozo (36 %) y en la de lavado (42 %). Un 80 % y un 88 % de los establecimientos contaban con agua de pozo y de lavado no aptas, respectivamente. Los niveles de mesófilos aerobios y de coliformes totales presentes en el agua de pozo mostraron una concordancia moderada con los detectados en el agua destinada al lavado. En virtud de estos resultados, puede afirmarse que un elevado porcentaje de los tambos ubicados en la cuenca lechera de Villa María emplean agua de calidad bacteriológica deficiente, no apta para el ordeño ni el lavado de las instalaciones.<br>Bacteriological contamination of well water and wash water in a random sample obtained from 50 farms from Villa María (Córdoba) dairy area, Argentina, was evaluated during a visit in 2007. Forty six percent and 24 % of farms showed an aerobic mesophilic bacteria count higher than 500 CFU/ml in wash water and well water, respectively. Escherichia coli was isolated in 20 % of samples from both sources. Pseudomonas aeruginosa showed high frequency of isolation in well water (36 %) and wash water (42 %). Eighty and eighty-eight percent of dairy farms have contaminated well water and wash water, respectively. The findings show moderate concordance between contamination of well water and wash water for mesophilic aerobics and total coliforms. The results reveal that a high percentage of dairy farms in the basin under study have poor bacteriological water quality, not suitable for milking and washing facilities

Prevalence and antibiotic susceptibility of coagulase-negative Staphylococcus species from bovine subclinical mastitis in dairy herds in the central region of Argentina

AbstractCoagulase-negative staphylococci (CNS) are a common cause of bovine subclinical mastitis (SCM). The prevalence of CNS species causing SCM identified by genotyping varies among countries. Overall, the antimicrobial resistance in this group of organisms is increasing worldwide; however, little information exists about a CNS species resistant to antibiotics. The aim of the present study was to genotypically characterize CNS at species level and to determine the prevalence and antibiotic resistance profiles of CNS species isolated from bovine SCM in 51 dairy herds located in the central region of the province of Cordoba, Argentina. In this study, we identified 219 CNS isolates at species level by PCR-restriction fragment length polymorphism of the groEL gene. Staphylococcus chromogenes (46.6%) and Staphylococcus haemolyticus (32%) were the most prevalent species. A minimum of three different CNS species were present in 41.2% of the herds. S. chromogenes was isolated from most of the herds (86.3%), whereas S. haemolyticus was isolated from 66.7% of them. The broth microdilution method was used to test in vitro antimicrobial susceptibility. Resistance to a single compound or two related compounds was expressed in 43.8% of the isolates. S. chromogenes and S. haemolyticus showed a very high proportion of isolates resistant to penicillin. Resistance to two or more non-related antimicrobials was found in 30.6% of all CNS. S. haemolyticus exhibited a higher frequency of resistance to two or more non-related antimicrobials than S. chromogenes

Detección molecular de cepas patógenas de Escherichia coli aisladas de terneros neonatos de tambo en la provincia de Córdoba, Argentina

The aim of this study was to perform a current molecular characterization of bovine pathogenic Escherichia coli strains isolated from random samplings in Argentinean dairy farms. Rectal swabs were obtained from 395 (63.7 %) healthy and 225 (36.3 %) diarrheic calves, belonging to 45 dairy farms in Cordoba Province, Argentina. E. coli isolates were examined for virulence genes (f5, f41, f17, sta, stb, lt, eae, vt) using PCR and the prevalence of E. coli virulence profiles was spatially described in terms of spatial distribution. A total of 30.1 % isolates were found to be positive for at least one of the virulence genes. Depending on the different gene combinations present, 11 virulence profiles were found. Most of the isolates analyzed had a single gene, and no combination of fimbrial and enterotoxin gene was predominant. There was no association between the frequency and distribution of E. coli virulence genes and calf health status. Most of the virulence profiles were compatible with ETEC strains and showed a homogeneous distribution over the sampled area. A clustering pattern for E. coli virulence profiles could not be recognized. This work provides updated information on the molecular characterization of pathogenic E. coli strains from dairy herds in Cordoba, Argentina. These findings would be important to formulate prevention programs and effective therapies for diarrhea in calves caused by E. coli.Fil: Picco, Natalia Yanina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alustiza, Fabrisio Eduardo. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bellingeri, Romina Valeria. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Grosso, Maria Carolina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Motta, Carlos E.. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Patologia Animal; ArgentinaFil: Larriestra, Alejandro J.. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Patologia Animal; ArgentinaFil: Vissio, Claudina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Patologia Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tiranti, Karina I.. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Patologia Animal; ArgentinaFil: Terzolo, Horacio R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Moreira, Ana R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Vivas, Adriana B.. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal; Argentin