ABSTRACT
Resumen: Las especies de Aeromonas de la familia Aeromonadaceae son bacilos gramnegativos, anaerobios facultativos, citocromo oxidasa, catalasa e indol-positivo. Se encuentran naturalmente en el medio ambiente, pero principalmente en agua dulce y salina, asimismo, se han aislado de vegetales, carne, mariscos y alimentos procesados. Las infecciones de piel y tejidos blandos por Aeromonas spp son poco frecuentes. Se han reportado en el mundo infecciones en tejidos blandos secundarias a traumatismo local en contacto con tierra o agua, a intervención quirúrgica o a diseminación hematógena en enfermos inmunodeprimidos a partir de translocación bacteriana intestinal. De los casos reportados en humanos la gastroenteritis se manifiesta con mayor frecuencia; sin embargo, se han descrito infecciones extraintestinales de gravedad que ponen en peligro la vida, como septicemia, fascitis necrotizante y mionecrosis. Comunicamos un caso de mionecrosis fulminante por Aeromonas caviae que evolucionó desfavorablemente con desenlace fatal.
Abstract: The Aeromonas species of the Aeromonadaceae family are gram-negative bacilli, facultative anaerobes, cytochrome oxidase, catalase and indole-positive bacilli. They are found naturally in the environment, but they are mainly found in fresh and salt water, and they have been isolated from vegetables, meat, seafood and processed foods. Skin and soft tissue infections caused by Aeromonas spp are rare. Soft tissue infections secondary to local trauma in contact with soil or water have been reported in the world, in surgical intervention or in hematogenous dissemination in immunosuppressed patients from intestinal bacterial translocation. Of the cases reported in humans, gastroenteritis is the most frequent; however, life-threatening extraintestinal infections such as septicemia, necrotizing fasciitis, and myonecrosis have been reported. This paper reports a case of fulminating myonecrosis caused by Aeromonas caviae, which evolved unfavorably, unfortunately with a fatal outcome.
ABSTRACT
SUMMARYIn the present study enterotoxic and cytotoxic activities of twenty Aeromonas caviaestrains were examined. They originated from fecal specimens of patients with acute diarrhea during an outbreak in Brazil in 2004. Culture supernatants of fourteen strains (70%) caused fluid accumulation in rabbit ileal intestinal loops and in suckling mice assays, and also showed a cytotoxic activity in Vero and Caco-2 cells. The enterotoxic and cytotoxic factors were heat-stable after culture supernatants treatment at 100 ºC. The results revealed that A. caviaestrains produce a putative diarrheagenic virulence factor, a heat-stable cytotoxic enterotoxin that could be linked to the diarrhea outbreak that took place in Brazil.
RESUMOEm 2004 ocorreu um surto de diarreia aguda no Estado de Pernambuco, Brasil. Setenta por cento (14 dos 20) dos sobrenadantes de cultura de Aeromonas caviae,isoladas neste episódio induziram acúmulo de líquido em testes de alça ligada de intestino de coelhos, assim como em teste em camundongos recém-nascidos. Os mesmos sobrenadantes mostraram também atividade citotóxica em células de Vero e Caco-2, mas não em células HeLa e HEp2. As atividades enterotóxicas e citotóxicas mantiveram-se mesmo após o aquecimento a 100 ºC dos sobrenadantes de cultura. Este trabalho revela a expressão de um provável fator diarreiogênico: uma enterotoxina-citotóxica termo-estável, produzida por A. caviaeque pode ser associada ao surto de diarreia ocorrido no Brasil. Atualmente estamos purificando esta enterotoxina termo-estável, com o objetivo de elucidar seu papel como fator de virulência na diarreia causada por A. caviae.
Subject(s)
Humans , Animals , Mice , Rabbits , Aeromonas caviae/pathogenicity , Enterotoxins/biosynthesis , Virulence Factors/biosynthesis , Brazil , Cell Line , Diarrhea/microbiology , Disease Outbreaks , Mice, Inbred BALB CABSTRACT
Peritonitis is a major cause of morbidity in peritoneal dialysis patients; however, Aeromonas caviae rarely causes peritonitis in these patients. We report peritonitis due to A. caviae in a 72-year-old male with end-stage renal failure who had been undergoing automated peritoneal dialysis for 1 year. The white blood cell (WBC) count in the peritoneal fluid was 2,722/mm3 with 85% neutrophils. Gram staining of the peritoneal fluid yielded Gram-negative rods. Empirical antibiotic therapy with ceftriaxone was initiated intraperitoneally. However, drug sensitivity testing revealed that the organism was resistant. On the third hospital day, A. caviae was cultured from the peritoneal effluent, and the antibiotic regimen was switched to ciprofloxacin. The patient recovered rapidly and the WBC count of the peritoneal effluent decreased. He was discharged and the intraperitoneal ciprofloxacin therapy was continued for 14 days. The peritoneal catheter was not removed.
Subject(s)
Animals , Humans , Male , Aeromonas , Aeromonas caviae , Ascitic Fluid , Catheters , Ceftriaxone , Ciprofloxacin , Guinea Pigs , Kidney Failure, Chronic , Leukocytes , Neutrophils , Peritoneal Dialysis , PeritonitisABSTRACT
This study aimed to compare the clinical presentations of Aeromonas hydrophila, A. veronii biovar sobria and A. caviae monomicrobial bacteremia by a retrospective method at three hospitals in Taiwan during an 8-yr period. There were 87 patients with A. hydrophila bacteremia, 45 with A. veronii biovar sobria bacteremia and 22 with A. caviae bacteremia. Compared with A. hydrophila and A. veronii biovar sobria bacteremia, A. caviae bacteremia was more healthcare-associated (45 vs 30 and 16%; P = 0.031). The patients with A. caviae bacteremias were less likely to have liver cirrhosis (27 vs 62 and 64%; P = 0.007) and severe complications such as shock (9 vs 40 and 47%; P = 0.009) and thrombocytopenia (45 vs 67 and 87%; P = 0.002). The APACHE II score was the most important risk factor of Aeromonas bacteremia-associated mortalities. The APACHE II scores of A. caviae bacteremias were lower than A. hydrophila bacteremia and A. veronii biovar sobria bacteremia (7 vs 14 and 16 points; P = 0.002). In conclusion, the clinical presentation of A. caviae bacteremia was much different from A. hydrophila and A. veronii biovar sobria bacteremia. The severity and mortality of A. caviae bacteremia were lower than A. hydrophila or A. veronii biovar sobria bacteremia.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , APACHE , Aeromonas caviae/drug effects , Aeromonas hydrophila/drug effects , Bacteremia/complications , Cross Infection/microbiology , Gram-Negative Bacterial Infections/complications , Liver Cirrhosis/microbiology , Retrospective Studies , Shock, Septic/microbiology , Taiwan , Thrombocytopenia/complicationsABSTRACT
Aeromonas caviae strains have been isolated from blood and stool cultures of three immunocompetent patients, residents of Northern India, who presented with community acquired septicemia without any recent history of diarrhea. Cell culture infectivity test performed on Hep-2 cells have shown substantial degree of invasiveness in the isolated strains. This case unleashes a possibility of asymptomatic gastrointestinal carriage of such strains of A. caviae in a very large population of India, as several areas of India have very high rates of Aeromonas induced acute diarrhea/gastroenteritis (up to 13 percent). It needs to be appraised further in India as well as other countries having high rates of Aeromonas induced acute diarrhea/gastroenteritis.
Subject(s)
Humans , Aeromonas/isolation & purification , Bacteremia/microbiology , Digestive System/microbiology , Gram-Negative Bacterial Infections/microbiology , Aeromonas/classification , Amikacin/therapeutic use , Anti-Bacterial Agents/therapeutic use , Bacteremia/diagnosis , Bacteremia/drug therapy , Carrier State , Community-Acquired Infections/diagnosis , Community-Acquired Infections/drug therapy , Community-Acquired Infections/microbiology , Feces/microbiology , Gram-Negative Bacterial Infections/diagnosis , Gram-Negative Bacterial Infections/drug therapy , Immunocompetence , IndiaABSTRACT
The cell surface carbohydrates of four strains of Aeromonas caviae were analyzed by agglutination and lectin-binding assays employing twenty highly purified lectins encompassing all sugar specificities. With the exception of L-fucose and sialic acid, the sugar residues were detected in A. caviae strains. A marked difference, however, in the pattern of cell surface carbohydrates in different A. caviae isolates was observed. Specific receptors for Tritricum vulgaris (WGA), Lycopersicon esculentum (LEL) and Solanum tuberosum (STA) (D-GlcNAc-binding lectins) were found only in ATCC 15468 strain, whereas Euonymus europaeus (EEL, D-Gal-binding lectin) sites were present exclusively in AeQ32 strain, those for Helix pomatia (HPA, D-GalNAc-binding lectin) in AeC398 and AeV11 strains, and for Canavalia ensiformes (Con A, D-Man-binding lectin) in ATCC 15468, AeC398, AeQ32 and AeV11 strains, after bacterial growing at 37ºC. On the other hand, specific receptors for WGA and EEL were completely abrogated growing the bacteria at 22ºC. Binding studies with 125I- labeled lectins from WGA, EEL and Con A were performed. These assays essentially confirmed the selectivity, demonstrated in the agglutination assays of these lectins for the A. caviae strains.
Os carboidratos de superfície celular de quatro amostras de Aeromonas caviae foram analisados por aglutinação e ensaios de ligação de lectinas empregando vinte lectinas altamente purificadas com especificidade para açúcares. Com exceção da L-fucose e do ácido siálico, os resíduos de açúcar foram detectados em amostras de A. caviae. Entretanto, foi observada uma diferença marcante no padrão de carboidratos de superfície celular em diferentes amostras de A. caviae. Receptores específicos para Tritricum vulgaris (WGA), Lycopersicon esculentum (LEL) e Solanum tuberosum (STA), lectinas de ligação a D-GlcNAc, foram encontrados apenas na amostra ATCC 15468, enquanto sítios de Euonymus europaes (EEL), lectina de ligação a D-Gal, estavam presentes exclusivamente na amostra AeQ32, sítios de Helix pomatia (HPA), lectina de ligação a D-GalNac, nas amostras AeC398 e AeV11 e de Canavalia ensiformis (Com A), lectina de ligação a D-Man, nas amostras ATCC 15468, AeC398, AeQ32 e AeV11, após crescimento bacteriano a 37ºC. Por outro lado, receptores específicos para WGA e EEL foram completamente abolidos após o crescimento das bactérias a 22ºC. Estudos de ligação com lectinas WGA, EEL e Con A marcadas com 125I também foram realizados. Esses ensaios confirmaram a seletividade, demonstrada em ensaios de aglutinação dessas lectinas para as amostras de A. caviae.
Subject(s)
Humans , Child , Aeromonas/isolation & purification , Carbohydrates/analysis , In Vitro Techniques , Lectins/analysis , Agglutination , Culture Media , MethodsABSTRACT
The growth property of pathogenic bacterium Aeromonas caviae strain CSS-4-2 which was isolated from the spleen of Carassius auratus of penze(♀) ? Cyprinus acutidorsalis (♂) that diseased septicemia was studied.The growth curve of CSS-4-2:lag phase was in 0～3h,log phase was in 3～30h, stationary phase was in 33～36h,decline phase was after 36h when CSS-4-2 was cultured shaking in tryptone liquid medium. It's optimum growth temperature ranges from 25℃ to 30℃, optimum growth pH ranges from 5 to 10, and optimum salinity ranges from 0% to 1% Nacl concentration .