ABSTRACT The symbiotic relationship between native microbiota and their hosts probably is a key factor in animal survival. In this study, the relationships of Pseudomonas spp. strains with specific biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs) in wild fish Chirostoma jordani, as well as the capacity of these bacteria to biotransform PAHs were evaluated. The activity of the naphthalene dioxygenase system of the bacteria exposed to 0.1, 1.0 and 10 µg/L of PAHs was higher than the mean isoform 1A1 (CYP1A1) of the wild fish, particularly bacterial species related to Pseudomonas spp. However, the epoxide hydrolase activity of the strains was lower in all cases compared to the fish. Glutathione S-transferase (GST) activity of the bacterial strains was lower than in the liver, but higher than in viscera of C. jordani. Using redundancy analysis, two differential patterns were found: (i) CYP1A1 activity of fish was induced by naphthalene and anthracene water levels independently of sampling season and lakes monitored, and (ii) the unidentified strain of the Pseudomonas genus biotransforms the endogenous levels of benzo[a]pyrene, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene in the fish allowing the hydroxylated metabolites to conjugate with glutathione through GST activity of the fish.

RESUMEN Las relaciones simbióticas entre la microbiota nativa y sus hospederos probablemente son un factor clave en la supervivencia animal. En el presente estudio se evaluaron las relaciones de cepas de Pseudomonas spp. con biomarcadores específicos de exposición a hidrocarburos aromáticos policíclicos (HAP) en Chirostoma jordani silvestre, así como la capacidad de estas bacterias para biotransformar HAP. La actividad del sistema de naftalen-dioxigenasa de las bacterias expuestas a 0,1, 1,0 y 10 μg/L de HAP fue superior al promedio de la isoforma 1A1 (CYP1A1) en los peces, particularmente cepas relacionadas con especies de Pseudomonas spp. Sin embargo, la actividad de la epóxido hidrolasa de las bacterias fue menor en comparación con los peces. La catálisis de la glutatión-S-transferasa (GST) de las cepas bacterianas fue menor que en el hígado pero mayor que en la víscera de C. jordani. Utilizando análisis de redundancia se encontraron dos patrones diferenciados: i) el CYP1A1 de los peces fue inducido por naftaleno y antraceno independientemente de la temporada de muestreo y de los lagos, y ii) la biotransformación de los niveles endógenos de benzo[a]pireno, benzo[k]fluoranteno e indeno[1,2,3-cd]pireno realizada por la cepa no identificada del género Pseudomonas permitió que los metabolitos hidroxilados se conjugaran con el glutatión a través de la actividad GST del pez.

A pentaplex PCR was developed and optimised to detect the genes that encode the five most important putative virulence factors in Aeromonas isolates. It seems to be more efficient than previously reported techniques and promises to be a powerful tool for more accurate risk assessments and for monitoring pathogenic strains.

The isolation of Aeromonas bestiarum from common carps (Cyprinus carpio L.), cultivated at Santa Maria Chapa de Mota, is reported for the first time. The genetic identification for differentiating A. bestiarum from A. salmonicida is here emphasized.

Se informa por primera ocasión el aislamiento de Aeromonas bestiarum a partir de carpa común (Cyprinus carpio L.) de cultivo, procedente de Santa María Chapa de Mota, Estado de México, México. Se enfatiza la identificación genética para la diferenciación entre A. salmonicida y A. bestiarum.

El carácter autolimitado de las infecciones entéricas provocadas por los bacilos gramnegativos anaerobios facultativos oxidasa positiva reserva la terapia antimicrobiana para los casos de disentería severa, enfermedad parecida al cólera o en las diarreas prolongadas, para los pacientes inmunocomprometidos con enfermedades subyacentes y ante una evidencia de infección extraintestinal. En esta investigación se estudió la susceptibilidad antimicrobiana de 89 cepas de bacilos gramnegativos anaerobios facultativos oxidasa positiva aislados de pacientes con enfermedad diarreica aguda enviados al Laboratorio Nacional de Referencias de Enfermedad Diarreica Aguda del Instituto de Medicina Tropical Pedro Kouri aislados de heces de pacientes con enfermedad diarreica aguda, frente a 23 antimicrobianos utilizando el método de Bauer-kirby con el fin de conocer en nuestro país la susceptibilidad antimicrobiana de estos microorganismos. El estudio de la susceptibilidad antimicrobiana mostró elevados porcentajes de resistencia de Aeromonas spp. frente a la cefazolina, cafalotina y cefalexina, la mayoría de las cepas de Vibrio cholerae no-01 y Plesiomonas shigelloides fueron resistentes al trimetoprim sulfametoxazol y cefazolina, respectivamente. Mientras que, la resistencia a la ampicilina fue común para los tres géneros. No se observaron cepas de Vibrio cholerae no-01 multirresistentes. Los resultados obtenidos señalan la importancia de implementar una continua y sistemática vigilancia microbiológica de estos agentes.

The self limit character of the enteric infections caused by the gramnegative bacilli anaerobes medical oxidasa positive reservation the therapy antimicrobiana for the cases of severe dysentery, similar illness to the cholera or in the lingering diarrhoeas, for the patient inmunocomprometidos with underlying illnesses and before an evidence of infection extraintestinal. In this investigation the susceptibility antimicrobiana of 89 stumps of bacilli gramnegativos isolated anaerobes medical positive oxidasa was studied of patient with illness diarrheic sharp correspondents to the National Laboratory of References of Illness Sharp Diarrheic of the Institute of Tropical Medicine Pedro isolated Kouri of grounds of patient with illness sharp diarrheic, in front of 23 antimicrobianos using the method of Bauer-kirby with the purpose of knowing in our country the susceptibility antimicrobiana of these microorganisms. The study of the susceptibility antimicrobiana showed high percentages of resistance of Aeromonas spp. in front of the cefazolina, cafalotina and cefalexina, most of the stumps of Vibrio cholerae no-01 and Plesiomonas shigelloides went resistant to the trimetoprim sulfametoxazol and cefazolina, respectively. While, the resistance to the ampicilina was common for the three goods. Strains of Vibrio cholerae were not observed no-01 multirresistentes. The obtained results point out the importance of implementing a continuous and systematic surveillance microbiological of these agents.

Objective: A study was carried out in Aeromonas strains isolated from patients with acute diarrheas in Cuba to find out the phenotypical expression of the cytotoxin and the enterotoxin as virulence factors. Methods: Forty six strains of the genus Aeromonas (A. hydrophila, A. veronii bv sobria, A. caviae, A. veronii bv veronii and Aeromonas spp.) isolated from stool specimens taken form patients with acute diarrheal disease were studied from 2005 to 2006. All the strains had their pattern of antimicrobial susceptibility pattern identified. The phenotypic expression of the cytotoxin and the enterotoxin in the Vero cell line was checked. Results: It was demonstrated that 91,31 % of the strains showed cytotoxic activity and 43,48 % of them enterotoxic activity. Regarding multiresistant strains, 93,75 % presented with at least one of the studied virulence factors. Conclusions: these results proved that the two researched virulence factors did exist in the studied strains, thus contributing to the many efforts that are being made to learn about the mechanisms of enteropathogenicity of this bacterial genus.

Objetivo: se realizó un estudio en cepas de Aeromonas aisladas de pacientes con enfermedad diarreica aguda en Cuba, para conocer la expresión fenotípica de la citotoxina y la enterotoxina como factores de virulencia. Métodos: se investigaron 46 cepas (A. hydrophila, A. veronii biovar sobria, A. caviae, A. veronii biovar veronii y Aeromonas spp.), aisladas de heces de pacientes con enfermedad diarreica aguda, en el período comprendido entre 2005 y 2006. Todas las cepas tenían identificado su patrón de susceptibilidad antimicrobiana. Se comprobó la expresión fenotípica de la citotoxina y la enterotoxina en la línea celular Vero. Resultados: el estudio demostró que 91,31 % de las cepas mostraron actividad citotóxica y 43,48 % actividad enterotóxica. De las cepas multirresistentes, 93,75 % presentó al menos un factor de virulencia estudiado. Conclusiones: los resultados demostraron que los 2 factores de virulencia investigados estuvieron presentes en las cepas estudiadas, contribuyendo así a los múltiples esfuerzos que se realizan para conocer los mecanismos de enteropatogenicidad de este género bacteriano.

A total of 221 strains of Aeromonas species isolated in Mexico from clinical (161), environmental (40), and food (20) samples were identified using the automated system bioMérieux-Vitek®. Antisera for serogroups O1 to 044 were tested using the Shimada and Sakazaki scheme. The K1 antigen was examined using as antiserum the O7:K1C of Escherichia coli. Besides, we studied the antimicrobial patterns according to Vitek AutoMicrobic system. Among the 161 clinical strains 60% were identified as A. hydrophila, 20.4% as A. caviae, and 19.25% as A. veronii biovar sobria. Only A. hydrophila and A. veronii biovar sobria were found in food (55 and 90% respectively) and environmental sources (45 and 10% respectively). Using "O" antisera, only 42.5% (94/221) of the strains were serologically identified, 55% (121/221) were non-typable, and 2.5% (6/221) were rough strains. Twenty-two different serogroups were found, O14, O16, O19, O22, and O34 represented 60% of the serotyped strains. More than 50% of Aeromonas strain examined (112/221) expressed K1 encapsulating antigen; this characteristic was predominant among Aeromonas strains of clinical origin. Resistance to ampicillin/sulbactam and cephazolin was detected in 100 and 67% of Aeromonas strain tested for their susceptibility to antibiotics. In conclusion, antibiotic-resistant Aeromonas species that possess the K1 encapsulating antigen and represent serogroups associated with clinical syndrome in man are not uncommon among Aeromonas strains isolated from clinical, food and environmental sources in Mexico.

A case of waterborne otitis in a patient with AIDS was report, who got infected with Vibrio fluvialis by swimming in a pool sea water. This is the first case reported in Cuba and as far as we know in the world. We describe the clinical features associated with this an unusual case and discuss its significance.

An 87 years-old female with a history of heart disease who has been presenting dysnea and fever for 2 months was evaluated. A sputum bacteriological study proved positive for Aeromonas hydrophila in the context of an existing lung cancer. The study was negative for acid fast bacilli.

Se evaluó una paciente de 87 años con antecedentes de cardiopatía que había estado presentando disnea y fiebre durante 2 meses. Un estudio bacteriológico resultó ser positivo a Aeromonas hydrophila en el contexto de un cáncer de pulmón existente. El estudio fue negativo para los bacilos ácidos rápidos.