The incidence of Shiga toxin-producing Escherichia coli in cattle with mastitis in Brazil.
OBJECTIVE
To determine the prevalence and molecular characteristics of Shiga toxin-producing Escherichia coli (STEC) isolates from bovine mastitic milk in Brazil.


RESULTS
A total of 2144 milk samples from dairy cattle showing mastitis were screened for the presence of E. coli. A total of 182 E. coli isolates were selected and examined. All were subjected to dot blot analysis using the CVD419 probe for the detection of the enterohaemolysin (hly) gene, and to a multiplex PCR for the detection of stx1, stx2 and eaeA genes. STEC were isolated from 22 (12.08%) milk samples. All the STEC isolates were tested for sensibility to 10 antimicrobials; the resistances most commonly observed were to cephalothin (86.3%), tetracycline (63.6%) and doxycycline (63.6%).


CONCLUSIONS
STEC isolates were found in bovine mastitic milk in Brazil.


CONCLUSIONS
STEC isolates from mastitic milk were potentially pathogenic for human in that they belonged to serogroups associated with diarrhoea and haemolytic-uraemic syndrome, some of them were stx2, eaeA and hly positive.
Lira
W M
WM
Departamento de Microbiologia, Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, Universidade Paulista, São Paulo, Brazil.
Macedo
C
C
Marin
J M
JM
D018829:Adhesins, Bacterial / Q000235:genetics; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D002417:Cattle; D002512:Cephalothin / Q000494:pharmacology; D004318:Doxycycline / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000235:genetics; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D006460:Hemolysin Proteins / Q000235:genetics; D008414:Mastitis, Bovine / Q000453:epidemiology / Q000382:microbiology*; D008892:Milk / Q000382:microbiology*; D015995:Prevalence; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D022603:Shiga Toxins / Q000235:genetics*; D013752:Tetracycline / Q000494:pharmacology
D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D022603:Shiga Toxins; C066219:enterohemolysin; C073819:eaeA protein, E coli; D013752:Tetracycline; D004318:Doxycycline; D002512:Cephalothin