RESUMEN
The increasing global public health concern of antimicrobial resistance (AMR) necessitates exploration of natural antimicrobial agents as potential alternatives. This study aimed to investigate antimicrobial activities of Saharan actinomycetes, with specific focus on the strain Streptomyces fimbriatus AC31, that holds promising potential as an alternative to combat AMR. In this context, 32 actinomycetes were isolated from El Atteuf (Ghardaïa), Algeria. Isolates obtained were characterized morphologically and biochemically. Screened isolate was identified by 16S rRNA gene sequencing. Classification of actinomycete isolates was carried out by UPGMA (Unweighted Pair Group Method with Arithmetic Mean). Then, they were screened for their antimicrobial activity by cross-streak method. Identification of 32 isolates revealed 5 genera: Streptomyces (65.63%), Nocardia (9.38%), Streptosporangium (9.38%), Nocardiopsis (9.38%) and Actinomadura (6.25%). According to the biochemical and physiological characteristics, UPGMA classified the isolates in 4 phenons. A number of 24 (75.00%) isolates were active against Gram-positive bacteria, 21 (65.63%) isolates were effective against Gram-negative bacteria, and 25 (78.13%) isolates inhibited Candida albicans. Screened strain Streptomyces fimbriatus AC31 showed highest antagonistic activity and revealed an inhibition zones of 41, 38, 41, 42, and 44 mm, against B. subtilis (ATCC 6633), E. coli (ATCC 8739), S. typhimurium (ATCC 13331), S. aureus (ATCC 6538) and C. albicans (ATCC 10231), respectively. Phylogenetic identification of the AC 31 isolate using 16S rRNA gene sequence showed similarity of 100% with Streptomyces fimbriatus NBRC 15411T. Actinomycete isolates characterized in this study were endowed with antimicrobial activity against various pathogenic microorganisms that could be used efficiently in developing new antimicrobial substances.
RESUMEN
An epidemiological study of gastrointestinal nematodes was carried out in naturally infected goats in the North West of Algeria. Coprological analyses were performed for 2 years from January 2014 to December 2015.Examination of 1591 goat samples revealed an overall prevalence of parasite eggs in feces of 96%; the values were very similar in both years at 97% in 2014 and 94.96% in 2015. Five types of nematode eggs were identified: strongyle (95.5%), Nematodirus spp. (19.4%), Marshallagia spp. (3.9%), Trichuris spp. (0.6%), and Skrjabinema spp. (2%).Also, fecal cultures showed the presence of Teladorsagia spp. (56%), Trichostrongylus spp. (20%), Chabertia spp. (10%), Haemonchus spp. (9%), and Oesophagostomum spp. (5%).Season, age, type of grazing, and area affected the epidemiology of gastrointestinal nematodes of goats. The season did not influence the prevalence observed in the 2 years, since no significant differences between the four seasons were observed. On the other hand, egg production was highest in winter and spring. The level of infection decreased with the animal's age. There were no significant differences between the prevalence in animals on irrigated and non-irrigated pastures, but there were differences in egg excretion. Additionally, no significant difference was observed between the coastal (Oran) and lowland (Mascara) regions in the prevalence or in average egg excretion.
