published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 143-183). Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 143-183). Also available online.

ROCHA, Rafael dos Santos. Caracterização polifásica da comunidade bacteriana heterotrófica de ambiente de carcinicultura frente às tetraciclinas. 2016. 105 f. Tese (Doutorado em Engenharia de Pesca)-Universidade Federal do Ceará, Fortaleza, 2016. / Submitted by Vitor Campos (vitband@gmail.com) on 2016-10-05T22:40:10Z No. of bitstreams: 1 2016_tese_rsrocha.pdf: 2184416 bytes, checksum: 17a4ecb8bd02fce65742927d2927e854 (MD5) / Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2016-10-05T23:19:54Z (GMT) No. of bitstreams: 1 2016_tese_rsrocha.pdf: 2184416 bytes, checksum: 17a4ecb8bd02fce65742927d2927e854 (MD5) / Made available in DSpace on 2016-10-05T23:19:54Z (GMT). No. of bitstreams: 1 2016_tese_rsrocha.pdf: 2184416 bytes, checksum: 17a4ecb8bd02fce65742927d2927e854 (MD5) Previous issue date: 2016 / Antimicrobial agents of tetracycline class has been extensively used in aquaculture for disease control and growth promotion. Thus, the aim of this study was to evaluate the polyphase profile of the bacterial community in shrimp farming environment front antimicrobial classes of tetracyclines, focusing on Vibrio genus. Water and sediment samples were collected four (4) shrimp farms: two (2) in the state of Ceará and two (2) in the state of Rio Grande do Norte, of points: estuary, supply channel, pond and drainage channel. Cultivable heterotrophic bacteria (CHB), with resistance to tetracycline (CHB+TET) and oxytetracycline (CHB+OTC), total Vibrio, positive sucrose Vibrio and sucrose negative Vibrio were surveyed by Standard Plate Count method (SPC). The strains isolated from CHB, CHB+TET, CHB+OTC and Vibrio underwent phenotypic identification. The phenotypic profile of antimicrobial susceptibility of strains of Vibrio and other BHC was compared between the disk diffusion techniques and macrodilution by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for tetracycline and oxytetracycline antimicrobials. Resistance genes tet(M), tet(S) otr(A) and otr(B) were investigated in strains characterized as phenotypically resistant. Diversity of heterotrophic bacteria is influenced by wet and rainy seasons and also by the different collection points within the shrimp farms. Overall, the CHB, CHB+TET and CHB+OTC and Vibrio counts differ between the collection seasons, with higher measurements during the rainy season to the points of pond and drainage channel. 146 strains of CHB, 57 of CHB+TET and 45 of CHB+OTC were isolated, of which the most representative genera were Vibrio and Enterobacter. A total of 100 strains of Vibrio were isolated, which V. coralliilyticus was the most representative species. Antimicrobial profile of Vibrio and other CHB differed between disk-diffusion and macrodilution techniques, being the macrodilution the most efficient in the characterization of resistance among isolates. All strains of Vibrio and other CHB, phenotypically resistant, presented the tet(M) gene as a determinant of resistance determinat, but tet(S) otr(A) and otr(B) genes were not observed. Thus, it proves that Vibrio genus is most abundant among herotrotrophic bacteria with resistance to tetracyclines, with the bacterial diversity strongly influenced by seasons. / Antimicrobianos da classe das tetraciclinas têm sido extensivamente usados em aquicultura para o controle de doenças e como promotores de crescimento. Dessa forma, foi traçado como objetivo geral avaliar o perfil polifásico da comunidade bacteriana de ambiente de criação de camarão frente aos antimicrobianos das classes das tetraciclinas, com enfoque no gênero Vibrio. Amostras de água e sedimento foram coletadas de quatro (4) fazendas de carcinicultura: duas (2) no estado do Ceará e duas (2) no estado do Rio Grande do Norte, dos pontos: estuário, canal de abastecimento, viveiro e canal de drenagem. Foram pesquisadas bactérias heterotróficas cultiváveis (BHC), com resistência à tetraciclina (BHC+TET) e oxitetraciclina (BHC+OTC), Vibrio total, sacarose positivos e negativos pelo método de Contagem Padrão em Placas (CPP). As cepas isoladas de BHC, BHC+TET, BHC+OTC e Vibrio foram submetidas à identificação fenotípica. O perfil fenotípico de susceptibilidade antimicrobiana das cepas de Vibrio e demais BHC foi comparado entre as técnicas de disco-difusão e macrodiluição, pela determinação da Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM) para os antimicrobianos tetraciclina e oxitetraciclina. Os genes de resistência tet(M), tet(S), otr(A) e otr(B) foram pesquisados nas cepas fenotipicamente caracterizadas como resistentes. A diversidade de bactérias heterotróficas foi influenciada pelos períodos de estio e chuvoso e também pelos diferentes pontos de coleta dentro das fazendas de carcinicultura. No geral, as contagens de BHC, BHC+TET e BHC+OTC e Vibrio e demais BHC diferiram entre os períodos de coleta, com quantificações superiores no período chuvoso para os pontos de coleta viveiro e canal de drenagem. Foram isoladas 146 cepas de BHC, 57 de BHC+TET, 25 de BHC+OTC, das quais os gêneros mais representativos foram Vibrio e Enterobacter. Foi possível o isolamento de 100 cepas de Vibrio, das quais V. coralliilyticus foi a espécie mais representativa. O perfil antimicrobiano diferiu entre as cepas de Vibrio e demais BHC entre as técnicas de disco-difusão e macrodiluição, sendo a de macrodiluição a mais eficiente na caracterização de resistência dentre os isolados. Todas as cepas de Vibrio e demais BHC, fenotipicamente resistentes, apresentaram o gene tet(M) como determinante de resistência, no entanto os genes tet(S), otr(A) e otr(B) não foram verificados. Com isso, comprovou-se que Vibrio é gênero mais abundante dentre as bactérias heterotróficas com resistência às tetraciclinas, estando a diversidade bacteriana fortemente influenciada pelos períodos do ano.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / Antimicrobial agents of tetracycline class has been extensively used in aquaculture for disease control and growth promotion. Thus, the aim of this study was to evaluate the polyphase profile of the bacterial community in shrimp farming environment front antimicrobial classes of tetracyclines, focusing on Vibrio genus. Water and sediment samples were collected four (4) shrimp farms: two (2) in the state of Cearà and two (2) in the state of Rio Grande do Norte, of points: estuary, supply channel, pond and drainage channel. Cultivable heterotrophic bacteria (CHB), with resistance to tetracycline (CHB+TET) and oxytetracycline (CHB+OTC), total Vibrio, positive sucrose Vibrio and sucrose negative Vibrio were surveyed by Standard Plate Count method (SPC). The strains isolated from CHB, CHB+TET, CHB+OTC and Vibrio underwent phenotypic identification. The phenotypic profile of antimicrobial susceptibility of strains of Vibrio and other BHC was compared between the disk diffusion techniques and macrodilution by determining the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for tetracycline and oxytetracycline antimicrobials. Resistance genes tet(M), tet(S) otr(A) and otr(B) were investigated in strains characterized as phenotypically resistant. Diversity of heterotrophic bacteria is influenced by wet and rainy seasons and also by the different collection points within the shrimp farms. Overall, the CHB, CHB+TET and CHB+OTC and Vibrio counts differ between the collection seasons, with higher measurements during the rainy season to the points of pond and drainage channel. 146 strains of CHB, 57 of CHB+TET and 45 of CHB+OTC were isolated, of which the most representative genera were Vibrio and Enterobacter. A total of 100 strains of Vibrio were isolated, which V. coralliilyticus was the most representative species. Antimicrobial profile of Vibrio and other CHB differed between disk-diffusion and macrodilution techniques, being the macrodilution the most efficient in the characterization of resistance among isolates. All strains of Vibrio and other CHB, phenotypically resistant, presented the tet(M) gene as a determinant of resistance determinat, but tet(S) otr(A) and otr(B) genes were not observed. Thus, it proves that Vibrio genus is most abundant among herotrotrophic bacteria with resistance to tetracyclines, with the bacterial diversity strongly influenced by seasons. / Antimicrobianos da classe das tetraciclinas tÃm sido extensivamente usados em aquicultura para o controle de doenÃas e como promotores de crescimento. Dessa forma, foi traÃado como objetivo geral avaliar o perfil polifÃsico da comunidade bacteriana de ambiente de criaÃÃo de camarÃo frente aos antimicrobianos das classes das tetraciclinas, com enfoque no gÃnero Vibrio. Amostras de Ãgua e sedimento foram coletadas de quatro (4) fazendas de carcinicultura: duas (2) no estado do Cearà e duas (2) no estado do Rio Grande do Norte, dos pontos: estuÃrio, canal de abastecimento, viveiro e canal de drenagem. Foram pesquisadas bactÃrias heterotrÃficas cultivÃveis (BHC), com resistÃncia à tetraciclina (BHC+TET) e oxitetraciclina (BHC+OTC), Vibrio total, sacarose positivos e negativos pelo mÃtodo de Contagem PadrÃo em Placas (CPP). As cepas isoladas de BHC, BHC+TET, BHC+OTC e Vibrio foram submetidas à identificaÃÃo fenotÃpica. O perfil fenotÃpico de susceptibilidade antimicrobiana das cepas de Vibrio e demais BHC foi comparado entre as tÃcnicas de disco-difusÃo e macrodiluiÃÃo, pela determinaÃÃo da ConcentraÃÃo InibitÃria MÃnima (CIM) e ConcentraÃÃo Bactericida MÃnima (CBM) para os antimicrobianos tetraciclina e oxitetraciclina. Os genes de resistÃncia tet(M), tet(S), otr(A) e otr(B) foram pesquisados nas cepas fenotipicamente caracterizadas como resistentes. A diversidade de bactÃrias heterotrÃficas foi influenciada pelos perÃodos de estio e chuvoso e tambÃm pelos diferentes pontos de coleta dentro das fazendas de carcinicultura. No geral, as contagens de BHC, BHC+TET e BHC+OTC e Vibrio e demais BHC diferiram entre os perÃodos de coleta, com quantificaÃÃes superiores no perÃodo chuvoso para os pontos de coleta viveiro e canal de drenagem. Foram isoladas 146 cepas de BHC, 57 de BHC+TET, 25 de BHC+OTC, das quais os gÃneros mais representativos foram Vibrio e Enterobacter. Foi possÃvel o isolamento de 100 cepas de Vibrio, das quais V. coralliilyticus foi a espÃcie mais representativa. O perfil antimicrobiano diferiu entre as cepas de Vibrio e demais BHC entre as tÃcnicas de disco-difusÃo e macrodiluiÃÃo, sendo a de macrodiluiÃÃo a mais eficiente na caracterizaÃÃo de resistÃncia dentre os isolados. Todas as cepas de Vibrio e demais BHC, fenotipicamente resistentes, apresentaram o gene tet(M) como determinante de resistÃncia, no entanto os genes tet(S), otr(A) e otr(B) nÃo foram verificados. Com isso, comprovou-se que Vibrio à gÃnero mais abundante dentre as bactÃrias heterotrÃficas com resistÃncia Ãs tetraciclinas, estando a diversidade bacteriana fortemente influenciada pelos perÃodos do ano.

Made available in DSpace on 2012-09-05T18:23:50Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 171.pdf: 2152393 bytes, checksum: b0b6fe8b0d3480409f4208b986d3d728 (MD5) Previous issue date: 2003 / O ecossistema aquático é habitado por mexilhões, animais filtradores que refletem a qualidade ambiental através da sua análise microbiológica. Neste estudo pretendeu-se avaliar a presença de patógenos, clássicos (Salmonella sp.) e emergentes (Vibrio vulnificus, Aeromonas hydrophila e Plesiomonas shigelloides), a partir de mexilhões in natura e pré-cozidos isolados de uma Estação Experimental de Cultivo de Mexilhões situada em Jurujuba, Niterói, Rio de Janeiro. Embora, não tenha sido identificado o patógeno Salmonella sp., as análises laboratoriais realizadas permitiram o isolamento de diversas espécies de microrganismos pertencentes às famílias Vibrionaceae e Aeromonadaceae, algumas com relevante potencial patogênico (Vibrio parahaemolyticus, V. vulnificus e A. hydrophila). Diversos microrganismos isolados apresentaram perfil de resistência a antimicrobianos utilizados na clínica humana (ampicilina, tetraciclina, nitrofurantoína, sulfametoxazol-trimetoprim e pefloxacina). Considerando a relevância epidemiológica dos agentes patogênicos identificados e os resultados obtidos nesta investigação, faz-se urgente alertar as autoridades sanitárias quanto à presença desses patógenos na cadeia alimentar e no ambiente. Dada sua capacidade de causar enfermidades diversas nas populações humanas após consumo de mexilhões in natura ou pré-cozidos, torna-se premente e de extrema importância o desenvolvimento de estratégias de vigilância epidemiológica e sanitária, assegurando, entre outras medidas, o monitoramento constante dos mexilhões oriundos da Baía de Guanabara, no sentido de prevenir ou minimizar os riscos nas diferentes etapas da sua extração e comercialização.

ROCHA, Rafael dos Santos.Perfil de susceptibilidade antimicrobiana e preliminar de virulência entre cepas de Vibrio spp. isoladas da água e sedimento do estuário do Rio Acaraú, Ceará, Brasil.2011. 85f.Dissertação(Mestrado em Engenharia de Pesca)-Centro de Ciências Agrárias, Universidade Federal do Ceará, Fortaleza, 2011. / Submitted by Maria Naires Souza (marianaires@ufc.br) on 2011-11-11T20:34:41Z No. of bitstreams: 1 2011-dis-rsrocha.pdf: 5922711 bytes, checksum: 312924caf40b38aff6a35077d066776c (MD5) / Approved for entry into archive by Aline Nascimento(vieiraaline@yahoo.com.br) on 2011-11-16T15:03:39Z (GMT) No. of bitstreams: 1 2011-dis-rsrocha.pdf: 5922711 bytes, checksum: 312924caf40b38aff6a35077d066776c (MD5) / Made available in DSpace on 2011-11-16T15:03:39Z (GMT). No. of bitstreams: 1 2011-dis-rsrocha.pdf: 5922711 bytes, checksum: 312924caf40b38aff6a35077d066776c (MD5) Previous issue date: 2011-03-25 / The estuarine environment is recognized as an intake of contaminated water from different sources. The genus Vibrio is found in those places, being reported in many papers resistant strains to antibiotics used routinely in medical treatment. Seventy strains of Vibrio were selected originated from samples of water and sediment from the Acaraú estuary, West coast of Ceará, Brazil to experiment. The antibiogram was proposed in two batteries, one with Mueller Hinton agar dissolved in distilled water (MH+DW) and the other in seawater (MH+SW), and is tested the presence of virulence factors protease (caseinase, elastase and gelatinase), lipases, phospholipases, DNases, amylase, urease, and hemolysin (β-hemolysis test by Kanagawa Wagatsuma agar). The antimicrobials tested were NAL, AMP, ATM, CFL, CIP, CHL, CTX, STP, GEN, OTC, PEN, TCY and STX. In MH+DW, the resistance profile was observed for 47 (67.1%) strains to PEN, 26 (37.1%) to AMP and CFL, 8 (11.4%) to OTC, 6 (8.6%) to TCY, 3 (4.3%) to ATM and 1 (1.4%) to CHL, while for MH+SW, 68 (97.1%) strains were resistant to OTC, 67 (95.7%) to TCY, 57 (81.4%) to PEN, 34 (48.6%) to CFL, 29 (41.4%) to AMP , 21 (30.0%) to STP, 20 (28.5%) to GEN, 5 (7.2%) to ATM and NAL, 3 (4.3%) to STX and 1 (1.4%) to CIP. The resistant strains in MH+DW were subjected to plasmid curing by acridine orange agent. Resistance plasmid was observed in 36.21% of resistant strains to AMP, 5.17% to ATM, 37.93% to CFL, 13.79% to OTC, 53.45% to PEN and 6.90% to TCY. By order of recurrence, 67 (91.42%) strains of Vibrio spp. have analyzed the enzyme urease, followed by 57 (81.42%) to lipase, 54 (77.14%) to amylase, 53 (75.72%) to gelatinase, 43 (61.42%) to caseinase, 26 (37.14%) to phospholipase, 17 (24.28%) to DNase, 16 (22.86%) to elastase and 13 (18.57%) to β-hemolysis (Kanagawa). Seawater influence significantly the characterization of the resistance of strains of Vibrio spp. analyzed mainly on the drugs of the tetracycline class, and has been detected multidrug resistant strains associated with preliminary virulence factors. / O ambiente estuarino é reconhecidamente um local de aporte de águas contaminadas de diferentes fontes. O gênero Vibrio é encontrado, naturalmente, nesses locais, sendo relatadas, em inúmeros trabalhos científicos, cepas resistentes a antimicrobianos utilizados, rotineiramente, no tratamento médico. Foram selecionadas setenta cepas de Vibrio oriundas de amostras de água e sedimento do estuário do Rio Acaraú, litoral Oeste do Ceará, Brasil para o experimento. O antibiograma foi proposto em duas baterias, sendo uma com ágar Mueller-Hinton solubilizado em água destilada (MH+AD) e a outra em água do mar (MH+AM), além de ser testada a presença dos fatores de virulência proteases (caseinase, elastase e gelatinase), lipases, fosfolipases, DNases, amilases, urease e hemolisinas (β-hemólise pelo teste de Kanagawa em ágar Wagatsuma). Os antimicrobianos testados foram NAL, AMP, ATM, CFL, CIP, CLO, CTX, EST, GEN, OTC, PEN, SUT e TET. Em MH+AD, o perfil de resistência foi verificado para 47 (67,1%) cepas a PEN, 26 (37,1%) cepas a AMP e CFL, 8 (11,4%) a OTC, 6 (8,6%) a TET, 3 (4,3%) a ATM, e 1 (1,4%) a CLO, enquanto para MH+AM, 68 (97,1%) cepas foram resistentes a OTC, 67 (95,7%) a TET, 57 (81,4%) a PEN, 34 (48,6%) a CFL, 29 (41,4%) a AMP, 21 (30,0%) a EST, 20 (28,5%) a GEN, 5 (7,2%) a ATM e NAL, 3 (4,3%) a SUT e 1 (1,4%) a CIP. As cepas resistentes em MH+AD foram submetidas à cura do plasmídio pelo agente curagênico acridine Orange. Foi verificada resistência plasmidial em 36,21% das cepas resistentes a AMP, 5,17% a ATM, 37,93% a CFL, 13,79% a OTC, 53,45% a PEN e 6,90% a TET. Por ordem de recorrência, 67 (91,42%) cepas de Vibrio spp. analisadas apresentam atividade da enzima urease, seguidas de 57 (81,42%) para lipase, 54 (77,14%) a amilase, 53 (75,72%) a gelatinase, 43 (61,42%) a caseinase, 26 (37,14%) a fosfolipase, 17 (24,28%) a DNase, 16 (22,86%) a elastase e 13 (18,57%) a β-hemólise (Kanagawa). A água do mar influenciou, significativamente, a caracterização da resistência das cepas de Vibrio spp. analisadas, principalmente, sobre os antimicrobianos das classes das tetraciclinas, além de ter sido detectada múltipla resistência associada à cepas com fatores preliminares de virulência.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O ambiente estuarino à reconhecidamente um local de aporte de Ãguas contaminadas de diferentes fontes. O gÃnero Vibrio à encontrado, naturalmente, nesses locais, sendo relatadas, em inÃmeros trabalhos cientÃficos, cepas resistentes a antimicrobianos utilizados, rotineiramente, no tratamento mÃdico. Foram selecionadas setenta cepas de Vibrio oriundas de amostras de Ãgua e sedimento do estuÃrio do Rio AcaraÃ, litoral Oeste do CearÃ, Brasil para o experimento. O antibiograma foi proposto em duas baterias, sendo uma com Ãgar Mueller-Hinton solubilizado em Ãgua destilada (MH+AD) e a outra em Ãgua do mar (MH+AM), alÃm de ser testada a presenÃa dos fatores de virulÃncia proteases (caseinase, elastase e gelatinase), lipases, fosfolipases, DNases, amilases, urease e hemolisinas (β-hemÃlise pelo teste de Kanagawa em Ãgar Wagatsuma). Os antimicrobianos testados foram NAL, AMP, ATM, CFL, CIP, CLO, CTX, EST, GEN, OTC, PEN, SUT e TET. Em MH+AD, o perfil de resistÃncia foi verificado para 47 (67,1%) cepas a PEN, 26 (37,1%) cepas a AMP e CFL, 8 (11,4%) a OTC, 6 (8,6%) a TET, 3 (4,3%) a ATM, e 1 (1,4%) a CLO, enquanto para MH+AM, 68 (97,1%) cepas foram resistentes a OTC, 67 (95,7%) a TET, 57 (81,4%) a PEN, 34 (48,6%) a CFL, 29 (41,4%) a AMP, 21 (30,0%) a EST, 20 (28,5%) a GEN, 5 (7,2%) a ATM e NAL, 3 (4,3%) a SUT e 1 (1,4%) a CIP. As cepas resistentes em MH+AD foram submetidas à cura do plasmÃdio pelo agente curagÃnico acridine Orange. Foi verificada resistÃncia plasmidial em 36,21% das cepas resistentes a AMP, 5,17% a ATM, 37,93% a CFL, 13,79% a OTC, 53,45% a PEN e 6,90% a TET. Por ordem de recorrÃncia, 67 (91,42%) cepas de Vibrio spp. analisadas apresentam atividade da enzima urease, seguidas de 57 (81,42%) para lipase, 54 (77,14%) a amilase, 53 (75,72%) a gelatinase, 43 (61,42%) a caseinase, 26 (37,14%) a fosfolipase, 17 (24,28%) a DNase, 16 (22,86%) a elastase e 13 (18,57%) a β-hemÃlise (Kanagawa). A Ãgua do mar influenciou, significativamente, a caracterizaÃÃo da resistÃncia das cepas de Vibrio spp. analisadas, principalmente, sobre os antimicrobianos das classes das tetraciclinas, alÃm de ter sido detectada mÃltipla resistÃncia associada à cepas com fatores preliminares de virulÃncia. / The estuarine environment is recognized as an intake of contaminated water from different sources. The genus Vibrio is found in those places, being reported in many papers resistant strains to antibiotics used routinely in medical treatment. Seventy strains of Vibrio were selected originated from samples of water and sediment from the Acaraà estuary, West coast of CearÃ, Brazil to experiment. The antibiogram was proposed in two batteries, one with Mueller Hinton agar dissolved in distilled water (MH+DW) and the other in seawater (MH+SW), and is tested the presence of virulence factors protease (caseinase, elastase and gelatinase), lipases, phospholipases, DNases, amylase, urease, and hemolysin (β-hemolysis test by Kanagawa Wagatsuma agar). The antimicrobials tested were NAL, AMP, ATM, CFL, CIP, CHL, CTX, STP, GEN, OTC, PEN, TCY and STX. In MH+DW, the resistance profile was observed for 47 (67.1%) strains to PEN, 26 (37.1%) to AMP and CFL, 8 (11.4%) to OTC, 6 (8.6%) to TCY, 3 (4.3%) to ATM and 1 (1.4%) to CHL, while for MH+SW, 68 (97.1%) strains were resistant to OTC, 67 (95.7%) to TCY, 57 (81.4%) to PEN, 34 (48.6%) to CFL, 29 (41.4%) to AMP , 21 (30.0%) to STP, 20 (28.5%) to GEN, 5 (7.2%) to ATM and NAL, 3 (4.3%) to STX and 1 (1.4%) to CIP. The resistant strains in MH+DW were subjected to plasmid curing by acridine orange agent. Resistance plasmid was observed in 36.21% of resistant strains to AMP, 5.17% to ATM, 37.93% to CFL, 13.79% to OTC, 53.45% to PEN and 6.90% to TCY. By order of recurrence, 67 (91.42%) strains of Vibrio spp. have analyzed the enzyme urease, followed by 57 (81.42%) to lipase, 54 (77.14%) to amylase, 53 (75.72%) to gelatinase, 43 (61.42%) to caseinase, 26 (37.14%) to phospholipase, 17 (24.28%) to DNase, 16 (22.86%) to elastase and 13 (18.57%) to β-hemolysis (Kanagawa). Seawater influence significantly the characterization of the resistance of strains of Vibrio spp. analyzed mainly on the drugs of the tetracycline class, and has been detected multidrug resistant strains associated with preliminary virulence factors.

Vibrio bacteria are emerging pathogens responsible for 80,000 illnesses and 100 deaths in the United States each year. Infections are directly linked to the marine environment and are acquired by consuming contaminated seafood or exposing wounds during aquatic activities. Florida has the highest national incidence of vibriosis, with 20% of its cases reported from the Indian River Lagoon region, a popular recreation destination. This study utilized a combination of cultivation and molecular techniques to investigate the local distribution of V. vulnificus, V. parahaemolyticus and V. cholerae in this local waterway. The targeted species were found in an array of samples which may facilitate their transmission to humans. Overall, these bacteria were abundant in estuarine sediments (Vp: 2,439 CFU/g, Vv: 303 CFU/g, Vc: 176 CFU/g), on the sharp edges of oyster shells (Vp: 82 CFU/cm, Vv: 102 CFU/cm, Vc: 41 CFU/cm), and in the water column (Vp: 3.78 CFU/ml, Vv: 5.51 CFU/ml, Vc: 2.46 CFU/ml). Vibrio also pose a hazard to recreational anglers as they were recovered from fish (Vp: 61%, Vv: 55%, Vc: 30%), live bait shrimp (Vp: 80%, Vv: 37%, Vc: 0%) and hooks (Vp: 32%, Vv: 18%, Vc: 0%). Additionally, a molecular analysis of the V. vulnificus virulence revealed that the local population was dominated by disease-causing (vcgC) strains, which may explain why wound-related infections are common in this region. Vibrio occurrence varied both spatially and temporally due to their relationship with salinity and temperature. These bacteria exhibited a strong negative correlation with salinity, being particularly abundant near freshwater discharge locations. Due to Florida’s year-round warm climate, these species were found to be permanent members of the local microbial community. Seasonal peaks in abundance occurred between August and October, a period which corresponds with the warmest water temperatures as well as frequent rainfall. Predictive models were constructed based on these parameters to provide a better understanding of how, when and where Vibrio spp. may be encountered by humans. This information is important for both water management and healthcare initiatives, with an overall goal of improving local recreational safety. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Doutor -- Escola Nacional de Saude Publica, Rio de Janeiro, 2003.