Aeromonas salmonicida is associated with superficial skin infections in fish. Its virulence factors allow colonization of water including surface water such as salt water, beaches, and fresh water wells. Moreover, it is possible for immunocompromised patients to develop invasive disease after chronic exposure to Aeromonas spp.Through contaminated water. While there are reports of Aeromonas spp. bacteremia following water ingestion, there have been no reports of A. salmonicida bacteremia from water consumption. We report the first case of A. salmonicida bacteremia in a patient with diabetes due to chronic consumption of well water.

Les plasmides confèrent aux bactéries qui les possèdent diverses fonctions pouvant accroître leurs chances de survie dans des environnements défavorables. C’est le cas d’Aeromonas salmonicida ssp. salmonicida, bactérie à l’origine de la furonculose chez les salmonidés. Elle possède trois petits plasmides (pAsa1, pAsa2 et pAsa3) qui sont cryptiques c’est-à-dire sans fonction connue. Pour compléter son plasmidome standard, s’ajoutent aux précédents, deux autres plasmides fréquemment retrouvés, pAsal1 et pAsa5, porteurs de gènes codant pour le système de sécrétion de type III, important facteur de virulence pour ce microorganisme. Enfin, ce ne sont pas moins de 17 plasmides porteurs de gènes de résistance aux antibiotiques et quatre supportant des facteurs de virulence qui ont été mis en évidence au cours des 30 dernières années pour cette bactérie. La propagation des gènes de résistance aux antibiotiques pose un problème dans le contexte vétérinaire puisqu’elle constitue, pour le moment, un obstacle au traitement efficace et durable contre la bactérie et conséquemment contre la furonculose. L’étude des petits plasmides d’A. salmonicida ssp. salmonicida s’inscrit dans cette démarche d’une meilleure connaissance de leur plasticité et de leur diversité. Ce projet a donc permis de mettre en évidence la présence de trois nouveaux petits plasmides : pAsa10, pAsaXI et pAsaXII. pAsa10 est la preuve supplémentaire que la propagation des gènes de résistance aux antibiotiques se poursuit, notamment par l’entremise du transposon Tn1721. L’analyse des séquences de pAsaXI et pAsaXII a permis de mettre en évidence des plasmides porteurs de nouvelles fonctionnalités pour A. salmonicida ssp. salmonicida, et des dérivés respectifs des plasmides cryptiques pAsa3 et pAsa2, très présents dans la bactérie, mais sans utilité apparente. Enfin, la haute capacité de transfert de ce microorganisme est encore démontrée, car ces plasmides sont identiques à d’autres retrouvés dans Shewanella baltica et Aeromonas bivalvium, respectivement. / Plasmids confer to the bacteria that possess them various functions that increase their chances of survival in adverse environments. This is the case with Aeromonas salmonicida ssp. salmonicida, a bacterium which causes furunculosis in salmonids. It has three small plasmids (pAsa1, pAsa2 and pAsa3) that are cryptic that is to say without a known function. To supplement its standard plasmidome, two other frequently found plasmids, pAsal1 and pAsa5, which are carriers of genes coding for the type III secretion system, an important virulence factor of this microorganism. Finally, there are no less than 17 plasmids with genes coding for antibiotic resistance and 4 bearing virulence factors that have been demonstrated over the last 30 years for this bacterium. The spread of antibiotic resistance poses a problem in the veterinary context, since it is currently an obstacle to effective and sustainable treatment against the bacterium and consequently to furunculosis. The study of the small plasmids of A. salmonicida ssp. salmonicida is part of this process of a better knowledge of their plasticity and diversity. This project highlighted the presence of three new small plasmids: pAsa10, pAsaXI and pAsaXII. pAsa10 is a new evidence that propagation of antibiotic resistance genes continues, notably through the transposon Tn1721. The analysis of pAsaXI and pAsaXII sequences allowed to identify plasmids carrying new functionalities for A. salmonicida ssp. salmonicida, and derivatives of cryptic plasmids pAsa3 and pAsa2, respectively, very present in the bacterium but without apparent utility. Finally, the high transfer capacity of this microorganism is further demonstrated because these plasmids are identical to others found in Shewanella baltica and Aeromonas bivalvium, respectively.

No description available.

Commercial catfish production is an inveterate industry within the southeastern United States. Bacterial disease is a significant detriment to global aquaculture, including the United States catfish industry. Among them, an atypical strain of the bacterium Aeromonas hydrophila has plagued the industry since the late 2000s. Atypical A. hydrophila (aAh) outbreaks are largely acute, resulting in catastrophic losses. The disease ecology, prevalence, and genetic distribution are poorly understood. Atypical Aeromonas hydrophila displays a rapid onset with few warning signs of the impending disease, making it difficult for early detection. At present there are two recognized haplotypes of aAh. This project aimed to investigate changes in the spatial and temporal distributions of these haplotypes. The analysis of clinical isolates from different geographic regions across multiple years revealed complete supplanting by the younger haplotype in the Mississippi Delta within 5 years of first isolation. Comparative genomics demonstrated distinct divergences in specific virulence components between the two strains, specifically the Type VI Secretion System, which may explain putative differences in outbreak dynamics and recent displacement of one strain by the other. Also, a rapid, non-lethal screening method was validated that can detect aAh within the catfish host. This method affords data collection regarding infection severity prior to onset of disease and, can predict aAh prevalence at the fish- and pond-levels. The occupancy model indicates more than half the population within a pond may be infected with aAh despite no overt signs of disease. Additionally, aAh is commonly present in approximately 10% of the population, providing the first evidence of a carrier state in this disease. Lastly, a compartmental SLIR model was used to investigate disease dynamics of aAh in catfish aquaculture ponds. Simulations suggest the introduction hypothesis does affect estimated pond profit and antibiotic intervention is an economical treatment for aAh. Routine monitoring was less economical and could dramatically reduce profit in some scenarios. Overall, this work expands our current knowledge of aAh in catfish aquaculture and lays the foundation for future studies investigating aAh management and mitigation of bacterial disease in catfish aquaculture.

N-acetil-glucosamina é um composto de importância biotecnológica com grande potencial de aplicação nas áreas de farmácia, medicina e dermatologia. É atualmente produzido pela hidrólise química da quitina, o polissacarideo mais abundante no ambiente marinho e o principal constituinte do exoesqueleto dos artrópodes. No entanto, os processos geralmente utilizados são prejudiciais ao meio ambiente, têm baixo rendimento e alto custo. Este estudo demonstra um dos mais eficientes processos de produção enzimática de N-acetil-glucosamina a partir de -quitina utilizando quitinases bacterianas como uma alternativa sustentável aos processos atuais e isolados de A. caviae com grande potencial para produção de quitinases e derivados de quitina. / N-acetyl-glucosamine (GlcNAc) is a compound of biotechnological importance with great application potential in the areas of pharmacy, medicine and dermatology. GlcNAc is currently produced by the chemical hydrolysis of chitin, the polysaccharide most abundant in the marine environment and the principal constituent of the exoskeleton of arthropods. However, the processes generally used are environmentally unfriendly, have low yield and high cost. This study demonstrates the most efficient processes for enzymatic production of N-acetyl-glucosamine from -chitin using bacterial chitinases as a sustainable alternative to the current processes and A. caviae isolates with great potential for chitinases and chitin derivatives production.

Neste estudo 60 cepas de Aeromonas, 15 A. hydrophila, 15 A. caviae, 15 A. sobria e 15 A. jandaei, isoladas de 5 diferentes pontos do reservatório de Guarapiranga, São Paulo, e previamente testada quanto à produção de fatores de virulência, acúmulo de fluído em alça ligada e hemólise em ágar sangue, foram submetidas a ribotipagem e a análise do perfil plasmidial. Cada cepa apresentou um perfil de ribotipagem diferente tendo-se observado para as espécies A. hydrophila e A. caviae a diferenciação em 3 agrupamentos, e A. sobria e A. jandaei dois agrupamentos cada. A análise do perfil plasmidial demonstrou que 13,4 por cento das A. hydrophila apresentaram um ou no máximo 2 plasmídios, enquanto 33,3 por cento das A. sobria e 53,3 por cento das A. jandaei apresentaram de 1 a 6 plasmídios para cada espécie; A. caviae não apresentou cepas contendo plasmídios. Não foi observada correlação entre a presença de plasmídios e a produção de fatores de virulência pelas cepas estudadas. A ribotipagem demonstrou haver um polimorfismo genômico dentro de uma mesma espécie de Aeromollas e, ainda, diferenciou cepas isoladas de um mesmo ponto de amostragem. Estas metodologias, ribotipagem e análise do perfil plasmidial, apresentam em geral características que são complementares, demonstrando ser ferramentas importantes a serem empregadas, tanto em estudos epidemiológicos como ecológicos. / In this work 60 Aeromonas strains, 15 A. hydrophila, 15 A. caviae, 15 A. sobria and 15 A. jandaei isolated from 5 different points of Guarapiranga Dam, São Paulo, and previously tested for virulence factors production (ileal loop assay and hemolysis on blood agar) were submitted to ribotyping and plasmidial profiles analysis. Each strain showed a different ribopattern and there were observed that for A. hydrophila and A. caviae each specie were grouped in 3 ribotypes, A. sobria and A. jandaei in 2 ribotype each. Plasmidial profiles analysis demonstrated that 13,4 per cent af A. hydrophila had at least one but no more than 2 plasmids, 33,3 per cent of A. sobria and 53,3 per cent af A. jandaei had from one to 6 plasmids each, and A. caviae didn\'t show to have any plasmids. There were not observed correlation between presence of plasmids and virulence factor production. Ribotyping showed that there are genomic polymorphism within the same Aeromonas specie and differentiate strains that were isolated from the same sample point, indicating that those methodologies have in general characteristics that are complementary and are important tools to be used either in epidemiological or ecological studies.

Em um total de 90 amostras de hortaliças, incluindo 30 de alface, 30 de agrião e 30 de escarola, foi verificada a ocorrência de Aeromonas do grupo A. hydrophila, empregando-se os métodos de semeadura direta em ágar amido-amplicilina (contagem) e após enriquecimento em caldo tripticase-soja adicionado de ampicilina (teste de presença/ausência). As incubações foram feitas a 28&#186;C, durante 24 horas. A presença dessas bactérias foi detectada em 43 (47,8%) das amostras analisadas, com contagens variando de < 102 a 2, 0x 106UFC/g. As amostras de agrião foram as que revelaram, na contagem, com maiores números de Aeromonas spp. Das 43 amostras positivas para Aeromonas spp. 9 (21,0%) revelaram-se com números superiores a 104 UFC/g. sendo que 7 eram de agrião . Dentre as amostras de hortaliças analisadas, as de agrião revelaram-se com positividade para Aeromonas do grupo A. hydrophila (70,0%) significativamente maior em relação às de alface (43,3%) e de escarola (30,0%) a nível de 5%. Não foram observadas diferenças significativas entre as positividades obtidas através do método de semeadura direta em placas e do teste de presença/ausência para as amostras de alface e de agrião. Para as amostras de escarola, a positividade foi significativamente mais alta no teste de presença/ausência. Do total de 143 cepas confirmadas como sendo do gênero Aeromonas, 138 (96,5%) eram de A. caviae, 4 (2,8%) de A. hydophila e 1 (0,7%) que, pelas suas características, foi considerada como Aeromonas atipica. Dos resultados obtidos, pode-se depreender que as hortaliças dos tipos analisados, alface, agrião e escarola, dado os níveis de contaminação observados, podem representar risco aos consumidores. / A total of 90 retail vegetable samples, including 30 of lettuce, 30 of water-cress and 30 of escarole were examined for the presence of Aeromonas of the A. hydrophila group, using two different isolation methods. One of the methods envolved direct plating on starch-ampicinin agar for the purpose of enumeration and the other one, after enrichment in trypticase-soy broth with ampicillin, for detection, both using 24 hour incubation at 28&#176C. Aeromonas spp. Were detected in 43 (47.8%) samples and their numbers varied from less than 102 up to 2.0x106 CFU/g. The water-cress samples were the ones to show greater numbers of Aeromonas spp. The counts of 9 (21%) of the 43 positive samples exceeded 104 CFU/g, 7 of them consisting of water-cress. The number of water-cress positive samples (70.0%) was significantly higher at 5% than those of lettuce (43.3%) and those of escarole (30.0%). No significant differences were found in relation to positivity for Aeromonas spp. Between both isolation methods used, regarding the lettuce and the water cress samples. On the other hand, with respect to the escarole samples, positivity was significantly superior for the isolation method envolving enrichment. In therms of species level identification, among 143 strains confirmed as being Aeromonas spp., 138 (96.51%) were A, cavia, 4 (2.81%) were A, hvdrophila and 1 (O,7%) was considered as atypical due to its different biochemical profile. The results show that the vegetables examined may represent risk to consumers in terms of presence and numbers of Aeromonas of the A, hvdrophila group.

INTRODUÇÃO: As Aeromonas são bactérias distribuídas predominantemente em meio aquático. São consideradas patógeno emergente, podendo causar doenças em peixes como também no homem. Os problemas mais comuns são a gastrenterite no homem e morte em peixes. OBJETIVO: Este estudo foi desenvolvido para comparar a identificação fenotípica com a genotípica, e também para conhecer o perfil de resistência aos antibióticos em Aeromonas caviae, A. aquariorum, e A. sanarellii isoladas do ambiente aquático e a presença de genes de virulência e resistência. MATERIAL E MÉTODOS: O DNA das 24 cepas em estudo foi extraído por choque térmico e purificado utilizando CTAB. Foram realizadas as PCRs para a detecção dos genes de virulência e dos genes de resistência, após a realização do antibiograma. RESULTADOS: Foram identificadas 4 A. caviae das quais 3(75,0 por cento) apresentaram pelo menos um dos genes act, ast ou alt. Das 3 A. aquariorum, 1(33,3 por cento) apresentaram positividade para os genes act e ast. Entre os 5 isolados de A. sanarellii 1(50,0 por cento) possuíam os genes alt e ast. Seis isolados não foram posicionados taxonomicamente entre as espécies descritas de Aeromonas, e dentre essas um exemplar apresentou o gene alt. Em relação às enzimas MBL e AmpC foram obtidos respectivamente: 3(100 por cento) e 3(100 por cento) em A. aquariorum; 2(50,0 por cento) e 4(100 por cento) em A. caviae; 3(75,0 por cento) e 5(100 por cento) em Aeromonas spp.; 1(20 por cento) e 5(100 por cento) A. sanarellii; Nenhum isolado apresentou resultado positivo, no teste fenotípico, para a produção de ESBL. Com a realização da PCR foi detectada a presença de 5 amostras com gene tipo blaMOX, 21blaCPHA , 17 tipo blaTEM e 2 cepH. CONCLUSÃO: Os resultados sugerem que os isolados podem servir potencialmente como reservatórios de resistência aos antimicrobianos e ainda, que os isolados podem ser considerados patógeno emergentes e significativos para a saúde pública / INTRODUCTION: Aeromonas spp. is predominantly distributed in the aquatic environment. They are regarded as emerging pathogen, causing disease in fish but also in man. The most common problems are gastroenteritis in humans and death in fish. OBJECTIVE: This study was designed to compare phenotypic with genotypic identification, and also to know the profile of antibiotic resistance in Aeromonas caviae, A. aquariorum, and A. sanarellii isolated from aquatic environment and the presence of virulence genes and resistance. MATERIAL AND METHODS: DNA from 24 strains under study was extracted by thermal shock and purified using CTAB. PCR reactions were performed for the detection of virulence and resistance genes, after the completion of the antibiotic resistance test. RESULTS: We identified four A. caviae from which 3(75.0per cent) had at least one of the genes act, ast or alt. From 3 A. aquariorum, 1(33.3per cent) was positive for the genes act and ast. Among the five isolated A. sanarellii, 1(50.0per cent) had the alt and ast genes Six isolates were not positioned within taxonomically described species of Aeromonas, and among these only one strain presented the alt gene. Regarding the MBL and AmpC it was obtained respectively: 3(100per cent) and 3(100per cent) isolates from A. aquariorum; 2(50.0per cent) and 4(100per cent) isolates from A. caviae; 4(66.7per cent) and 3(50.0per cent) isolates from Aeromonas spp.; and 1(20per cent) and 5 (100per cent) isolates from A. sanarellii. None of the isolates showed positive results in the phenotypic test for ESBL production. The PCR reaction detected the presence of 5 strains with blaMOX-like gene; 21 with blaCPHA gene; 17 with blaTEM-like gene and 2 with cepH gene. CONCLUSION: These findings suggest that the isolates may serve as potential reservoirs of antimicrobial resistance and also that the isolates could be considered emerging pathogens of public health significance

INTRODUÇÃO: As Aeromonas são bactérias distribuídas predominantemente em meio aquático. São consideradas patógeno emergente, podendo causar doenças em peixes como também no homem. Os problemas mais comuns são a gastrenterite no homem e morte em peixes. OBJETIVO: Este estudo foi desenvolvido para comparar a identificação fenotípica com a genotípica, e também para conhecer o perfil de resistência aos antibióticos em Aeromonas caviae, A. aquariorum, e A. sanarellii isoladas do ambiente aquático e a presença de genes de virulência e resistência. MATERIAL E MÉTODOS: O DNA das 24 cepas em estudo foi extraído por choque térmico e purificado utilizando CTAB. Foram realizadas as PCRs para a detecção dos genes de virulência e dos genes de resistência, após a realização do antibiograma. RESULTADOS: Foram identificadas 4 A. caviae das quais 3(75,0 por cento) apresentaram pelo menos um dos genes act, ast ou alt. Das 3 A. aquariorum, 1(33,3 por cento) apresentaram positividade para os genes act e ast. Entre os 5 isolados de A. sanarellii 1(50,0 por cento) possuíam os genes alt e ast. Seis isolados não foram posicionados taxonomicamente entre as espécies descritas de Aeromonas, e dentre essas um exemplar apresentou o gene alt. Em relação às enzimas MBL e AmpC foram obtidos respectivamente: 3(100 por cento) e 3(100 por cento) em A. aquariorum; 2(50,0 por cento) e 4(100 por cento) em A. caviae; 3(75,0 por cento) e 5(100 por cento) em Aeromonas spp.; 1(20 por cento) e 5(100 por cento) A. sanarellii; Nenhum isolado apresentou resultado positivo, no teste fenotípico, para a produção de ESBL. Com a realização da PCR foi detectada a presença de 5 amostras com gene tipo blaMOX, 21blaCPHA , 17 tipo blaTEM e 2 cepH. CONCLUSÃO: Os resultados sugerem que os isolados podem servir potencialmente como reservatórios de resistência aos antimicrobianos e ainda, que os isolados podem ser considerados patógeno emergentes e significativos para a saúde pública / INTRODUCTION: Aeromonas spp. is predominantly distributed in the aquatic environment. They are regarded as emerging pathogen, causing disease in fish but also in man. The most common problems are gastroenteritis in humans and death in fish. OBJECTIVE: This study was designed to compare phenotypic with genotypic identification, and also to know the profile of antibiotic resistance in Aeromonas caviae, A. aquariorum, and A. sanarellii isolated from aquatic environment and the presence of virulence genes and resistance. MATERIAL AND METHODS: DNA from 24 strains under study was extracted by thermal shock and purified using CTAB. PCR reactions were performed for the detection of virulence and resistance genes, after the completion of the antibiotic resistance test. RESULTS: We identified four A. caviae from which 3(75.0per cent) had at least one of the genes act, ast or alt. From 3 A. aquariorum, 1(33.3per cent) was positive for the genes act and ast. Among the five isolated A. sanarellii, 1(50.0per cent) had the alt and ast genes Six isolates were not positioned within taxonomically described species of Aeromonas, and among these only one strain presented the alt gene. Regarding the MBL and AmpC it was obtained respectively: 3(100per cent) and 3(100per cent) isolates from A. aquariorum; 2(50.0per cent) and 4(100per cent) isolates from A. caviae; 4(66.7per cent) and 3(50.0per cent) isolates from Aeromonas spp.; and 1(20per cent) and 5 (100per cent) isolates from A. sanarellii. None of the isolates showed positive results in the phenotypic test for ESBL production. The PCR reaction detected the presence of 5 strains with blaMOX-like gene; 21 with blaCPHA gene; 17 with blaTEM-like gene and 2 with cepH gene. CONCLUSION: These findings suggest that the isolates may serve as potential reservoirs of antimicrobial resistance and also that the isolates could be considered emerging pathogens of public health significance

Neste estudo 60 cepas de Aeromonas, 15 A. hydrophila, 15 A. caviae, 15 A. sobria e 15 A. jandaei, isoladas de 5 diferentes pontos do reservatório de Guarapiranga, São Paulo, e previamente testada quanto à produção de fatores de virulência, acúmulo de fluído em alça ligada e hemólise em ágar sangue, foram submetidas a ribotipagem e a análise do perfil plasmidial. Cada cepa apresentou um perfil de ribotipagem diferente tendo-se observado para as espécies A. hydrophila e A. caviae a diferenciação em 3 agrupamentos, e A. sobria e A. jandaei dois agrupamentos cada. A análise do perfil plasmidial demonstrou que 13,4 por cento das A. hydrophila apresentaram um ou no máximo 2 plasmídios, enquanto 33,3 por cento das A. sobria e 53,3 por cento das A. jandaei apresentaram de 1 a 6 plasmídios para cada espécie; A. caviae não apresentou cepas contendo plasmídios. Não foi observada correlação entre a presença de plasmídios e a produção de fatores de virulência pelas cepas estudadas. A ribotipagem demonstrou haver um polimorfismo genômico dentro de uma mesma espécie de Aeromollas e, ainda, diferenciou cepas isoladas de um mesmo ponto de amostragem. Estas metodologias, ribotipagem e análise do perfil plasmidial, apresentam em geral características que são complementares, demonstrando ser ferramentas importantes a serem empregadas, tanto em estudos epidemiológicos como ecológicos. / In this work 60 Aeromonas strains, 15 A. hydrophila, 15 A. caviae, 15 A. sobria and 15 A. jandaei isolated from 5 different points of Guarapiranga Dam, São Paulo, and previously tested for virulence factors production (ileal loop assay and hemolysis on blood agar) were submitted to ribotyping and plasmidial profiles analysis. Each strain showed a different ribopattern and there were observed that for A. hydrophila and A. caviae each specie were grouped in 3 ribotypes, A. sobria and A. jandaei in 2 ribotype each. Plasmidial profiles analysis demonstrated that 13,4 per cent af A. hydrophila had at least one but no more than 2 plasmids, 33,3 per cent of A. sobria and 53,3 per cent af A. jandaei had from one to 6 plasmids each, and A. caviae didn\'t show to have any plasmids. There were not observed correlation between presence of plasmids and virulence factor production. Ribotyping showed that there are genomic polymorphism within the same Aeromonas specie and differentiate strains that were isolated from the same sample point, indicating that those methodologies have in general characteristics that are complementary and are important tools to be used either in epidemiological or ecological studies.