Low occurrence of Listeria monocytogenes on bovine hides and carcasses in Minas Gerais State, Brazil: molecular characterization and antimicrobial resistance.

Listeria monocytogenes occurrence was assessed in three slaughterhouses located in Minas Gerais state, Brazil, by analysis of 209 bovine carcasses. Four sponge samples were obtained from each carcass in different steps (A, from hide, before bleeding; B, after hide removal; C, after evisceration; and D, after end washing), resulting in a total of 836 samples. The samples were tested for the presence of L. monocytogenes according to the International Organization for Standardization 11290-1, and positive results were recorded in steps A (1 of 209) and D (1 of 209) from slaughterhouse 03. L. monocytogenes isolates (n = 5) were identified by multiplex PCR as belonging to serogroup IIc (representing serotypes 1/2c or 3c) and presented identical pulsed-field gel electrophoresis profiles; in addition, the isolates harbored the virulence genes inlA, inlB, inlC, inlJ, plcA, hlyA, actA, and iap and were sensitive to ampicillin, vancomycin, gentamicin, erythromycin, tetracycline, rifampin, chloramphenicol, trimethoprim, and sulfamethoxazole. The obtained data indicated a low occurrence of L. monocytogenes on bovine hides and carcasses from slaughterhouses located in Minas Gerais state, Brazil, and the presence of distinct virulence makers and susceptibility to a variety of antimicrobials by the obtained isolates.

Enzymatic characterization of Vibrio alginolyticus strains isolated from bivalves harvested at Venice Lagoon (Italy) and Guanabara Bay (Brazil).

The aquatic ecosystem is the natural habitat of microorganisms including Vibrio and Aeromonas genus which are pathogenic to human and animals. In the present investigation the frequency of these bacteria and the enzymatic characteristics of 34 Vibrio alginolyticus strains isolated from bivalves harvested in Venice Lagoon (Italy) and Guanabara Bay (Brazil) were carried out from November 2003 to February 2004. The mussels' samples were submitted to enrichment in Alkaline Peptone Water (APW) added with 1% of sodium chloride (NaCl) and APW plus 3% NaCl incubated at 37 degrees C for 18-24 h. Following the samples were streaked onto TCBS Agar (Thiossulfate Citrate Bile Sucrose Agar) and the suspected colonies were submitted to biochemical characterization. Also, the Vibrio alginolyticus strains were evaluated to collagenase, elastase and chondroitinase production. The results showed the isolation of 127 microorganisms distributed as follows: 105 Vibrio strains such as V. alginolyticus (32.4%), V. harveyi (19%) and V. parahaemolyticus (7.6%), 20 Aeromonas strains and two Plesiomonas shigelloides were the main pathogens isolated. We observed the production of the three enzymes from V. alginolyticus strains considered as the main virulence factors of the bacteria, especially in cases of human dermatological infection.

Enzymatic characterization of Vibrio alginolyticus strains isolated from bivalves harvested at Venice Lagoon (Italy) and Guanabara Bay (Brazil) / Caracterização enzimática de cepas de Vibrio alginolyticus isoladas de bivalves coletados na Lagoa de Veneza (Itália) e Baía de Guanabara (Brasil)

The aquatic ecosystem is the natural habitat of microorganisms including Vibrio and Aeromonas genus which are pathogenic to human and animals. In the present investigation the frequency of these bacteria and the enzymatic characteristics of 34 Vibrio alginolyticus strains isolated from bivalves harvested in Venice Lagoon (Italy) and Guanabara Bay (Brazil) were carried out from November 2003 to February 2004. The mussels' samples were submitted to enrichment in Alkaline Peptone Water (APW) added with 1 percent of sodium chloride (NaCl) and APW plus 3 percent NaCl incubated at 37 ºC for 18-24h. Following the samples were streaked onto TCBS Agar (Thiossulfate Citrate Bile Sucrose Agar) and the suspected colonies were submitted to biochemical characterization. Also, the Vibrio alginolyticus strains were evaluated to collagenase, elastase and chondroitinase production. The results showed the isolation of 127 microorganisms distributed as follows: 105 Vibrio strains such as V. alginolyticus (32.4 percent), V. harveyi (19 percent) and V. parahaemolyticus (7.6 percent), 20 Aeromonas strains and two Plesiomonas shigelloides were the main pathogens isolated. We observed the production of the three enzymes from V. alginolyticus strains considered as the main virulence factors of the bacteria, especially in cases of human dermatological infection.

O ecossistema aquático é o habitat natural de microrganismos incluindo aqueles dos gêneros Vibrio e Aeromonas os quais são patogênicos para o homem e animais. Na presente investigação foi avaliada a freqüência destas bactérias e a característica enzimática de 34 cepas de Vibrio alginolyticus isoladas de bivalves coletados na Lagoa de Venice (Itália) e Baía de Guanabara (Brasil) durante o período de Novembro-2003 a Fevereiro-2004. As amostras de mexilhões foram submetidas a enriquecimento em Água Peptonada Alcalina (APA) adicionada de 1 por cento de Cloreto de Sódio (NaCl) e APA com 3 por cento de NaCl (37 ºC/18-24h). Em seguida as amostras foram semeadas em Agar TCBS (Agar Tiossulfato Citrato Bile Sacarose) e as colônias suspeitas foram submetidas à caracterização bioquímica. As cepas de Vibrio alginolyticus foram avaliadas quanto à produção das enzimas colagenase, elastase e condroitinase. Os resultados demonstraram o isolamento de 127 microrganismos assim distribuídos: 105 cepas de Vibrio das quais V. alginolyticus (32,4 por cento), V. harveyi (19 por cento) e V. parahaemolyticus (7,6 por cento), 20 cepas de Aeromonas e 2 Plesiomonas shigelloides foram os principais patógenos isolados. Observou-se a produção das três enzimas a partir de V. alginolyticus, consideradas principais fatores de virulência da bactéria, em especial em casos de infecção dermatológica humana.