No abstract

A b s t r a c tThe aim of this study was to investigate the capacity of Streptococcus suis strains to form biofilms and to evaluate the antimicrobial activity of Penicillin G and N-acetylcystein (NAC) on both S. suis sessile and planktonic forms. Only non-typeable isolates of S. suis were correlated with a greater biofilm formation capacity. The MCI of Penicillin G and NAC required for inhibiting biofilm growth were higher than the required concentration for inhibiting planktonic growth. The combinations of NAC and Penicillin G showed a strong synergistic activity that inhibited biofilm formation and disrupted the pre-formed biofilm of S. suis.

Mycoplasmas are of great concern in veterinary medicine since they are responsible for economic losses in animal production. The most important avian mycoplasmas that cause severe respiratory disease in chickens and turkeys are Mycoplasma gallisepticum and M. synoviae. M. iowae and M. meleagrides affect turkeys alone (Fan et al., 1995).Chronic respiratory syndrome (CRS) in birds is a disease with a multifactorial aetiology. M. gallisepticum and M. synoviae are the most important pathogens in CRS, although Citti and Rosengarten (1997) indicate that other species may also participate in the disease.In Cuba, CRS causes losses of some US$1 million per year. Recent data (Instituto Medicina Veterinaria, 2003) show that in the chicken-raising industry CRS is the second most important cause of death induced by an infectious agent, with an incidence of 12.67%.In 1997, during field investigations of an outbreak of CRS in western Cuba, mycoplasmas were isolated from chickens with respiratory problems. Lobo (1998) showed the incidence of M. gallisepticum, M. synoviae and M. pullorum in these diseased birds to be 40%, 30% and 22% respectively.For a long time M. pullorum was thought to be a saprophytic organism of the avian respiratory tract (Jordan, 1985), but since 1995 it has been isolated alone and with other mycoplasma species from birds with CRS (Bencina et al., 1987). Two isolates with the biochemical and serological characteristics of M. pullorum have been isolated from adult turkeys and dead turkey embryos in France (Moalic et al., 1997). AbstractMycoplasmas were isolated from chickens with respiratory problems during field investigations of a concentrated respiratory disease outbreak in western Cuba, 1997. A high percentage of mycoplasma cultures from tracheas and air-sac lesions yielded pure cultures of Mycoplasma pullorum. The aim of the present work was to investigate the heterogeneity among M. pullorum isolates from Cuba and strains from other countries using random amplified polymorphic DNA (RAPD) techniques. The results show that the RAPD method may be a useful identification tool for studying the epidemiology of poultry mycoplasmosis in Cuba.Key words: avian mycoplasmosis, RAPD, chronic respiratory syndrome. ResumenNota corta. Análisis de heterogeneidad entre aislados de Mycoplasma pullorum por medio de técnicas de amplificación de DNA polimórficoEn 1997 se aislaron micoplasmas en el curso de investigaciones de campo en pollos con un brote de enfermedad respiratoria localizada en la zona oeste de Cuba. Un alto porcentaje de los cultivos de micoplasmas procedentes de lesiones de tráquea y alveolos revelaron la presencia de Mycoplasma pullorum. El objetivo de este trabajo fue investigar la heterogeneidad de los aislados cubanos entre sí y con cepas de otros países, mediante la técnica RAPD (DNA polimórfico amplificado al azar). Los resultados muestran que la técnica RAPD puede ser una herramienta de identificación útil en el estudio de la epidemiología de la micoplasmosis aviar en Cuba.Palabras clave: micop...

M. hyorhinis is considered one of the etiological agents of arthritis in sucking pigs, but recently as seen, some strains can produce pneumonia that could not be distinguished from the mycoplasmosis caused by M. hyopneumoniae. The study was conducted to research the presence of Mycoplasma hyorhinis (M. hyorhinis ) in different regions of the country from exudates of pig lungs with typical EP lesions. Exudates from 280 pig lungs with typical EP lesions were studied using molecular techniques such as PCR, real time PCR and amplification of the 16S-23S rRNA. It was detected that the 66% of the samples studied resulted positive to M. hyorhinis, and the presence of this species was detected in all the provinces. Amplification and studies on the intergenic region 16S-23S of M. hyorhinis rRNA demonstrated the existing variability among strains of a same species. This study is the first report on M. hyorhinis detection in Cuba