rRNA Nucleotide Sequence Research Articles

Eulimdana clava (Nematoda: Filarioidea) infection in domestic pigeons (Columba livia domestica): Molecular characterization and pathological changes

Filarial nematodes of the Eulimdana genus inhabit subcutaneous tissue of various avian species, mostly Charadriiforme birds. In domestic pigeons, E. clava is the only species recorded in the subcutaneous tissue in a number of isolated cases. In the present study, we discuss the morphology and histopathology of filarial nematodes recovered from subcutaneous tissue of domestic pigeons in Bosnia and Herzegovina. In total 110 pigeons were submitted to necropsy at the Department of Pathology of the Faculty of Veterinary Medicine in Sarajevo. At necropsy, in four pigeons (3.6%) numerous thread-like 0.9–2.1 cm long nematode parasites were observed in the subcutaneous tissue, peritracheal and periesophageal connective tissue. In one pigeon, the parasites were also found free in the body cavity around the heart and lungs. In addition, several 80–90 μm long microfilariae were noted in the tissue cross-sections. No significant lesions were observed associated with adult parasites or microfilariae. Based on morphology, host species and localization detected parasites were identified as E. clava. Molecular analyses of the cox1 and 12S rRNA nucleotide sequences herein generated revealed the close genetic relationship to other filarioid nematodes. The importance of the nematodes in pigeons and the lack of sequences in genetic databases for comparison of avian filarial parasites are emphasized.

Ecological Niche Analysis of Streptomyces sp. Amet_ytc 21 nov. Strain Isolated from Marine Intertidal Zones of bay of Bengal and Buckingham Canal

Objective:To explore intertidal zone Swell seawater (High tide) for presence of novel Halotolerant Marine Actinomycetes (HTMA). Methods: Sea water analysis performed to estimate physiochemical parameters of unique Habitat. Phenotypic and genotypic analysis of isolated Halotolerant Marine Actinomycetes strains. Bioinformatics based analysis of novel HTMA Strain AMET YTC_21. Results: Physiochemical parameters of samples were as Temperature Seawater (28.00±0.50)°C, Salinity (34.96±0.05) ppt, Electrical Conductivity (34.96±0.05) µs/cm, pH (8.88±0.084), Dissolved Oxygen (11.94±0.11) mg/L, NO3 (0.25±0.021) mg/L, Total Dissolved Solids (27850.2±0.44) mg/L and Total PO4(0.013±0.00)mg/L. Salt tolerance, pH and temperature tolerance of selected HTMA strains and selection of potential strain for genetic analysis. Bioinformatics based Homology modeling and Phylogenetic tree analysis of novel Streptomyces sp. AMET_YTC21 strain. Conclusion: In the present study molecular identification by 16s rRNA gene sequencing of the isolated HTMA strain confirmed the organism a streptomyces sp. AMET_YTC21. The 16s rRNA nucleotide sequence was submitted to Gen bank in NCBI and the accession number obtained as Bank It KY072795. Morphological and biochemical evidence also suggested the presence of novel strain with high pH, Salt and temperature tolerance as Halotolerant Marine Actinomycetes. The obtained results will help us to determine the right candidate for novel therapeutic enzyme production.

Careful use of 16S rRNA gene sequence similarity values for the identification of Mycobacterium species.

In order to evaluate the suitability of 16S rRNA nucleotide sequence similarity for the classification of new Mycobacterium isolates at the species level, we systematically studied the pairwise identity values of this gene for 131 Mycobacterium species with standing in nomenclature. Only one of the studied species, M. poriferae (0.76%), strictly respected the 95% and 98.65% threshold values currently recommended to determine the affiliation of bacterial isolates to an existing or new genus or species, respectively. All other species exhibited at least an identity value >98.65% and/or <95% with another Mycobacterium species. Therefore, we suggest that interpretation of interspecies 16S rRNA identity values should be made cautiously when classifying a new mycobacterial isolate at the species level.

Isolation and screening of Lactobacillus species from dogs for probiotic action

The present study aimed at the detection of suitable Lactobacillus species from dogs for usage as probiotic. A total of 67 rectal swabs from healthy pups were analyzed and 49 (73.1%) Lactobacillus isolates were identified based on morphological, biochemical characteristics and confirmed by genus specific PCR targeting 16S rRNA gene. A total of 20 isolates that showed strong aggregation, high cell surface hydrophobicity, acid and bile tolerance were screened for in-vitro antibacterial activity by agar well diffusion assay, where prominent inhibitory zones were observed against majority of the test pathogens. Reduction in antibacterial activity was noticed after neutralization, proteinase K and heat treatment of supernatants. Partial 16S rRNA nucleotide sequence analysis of seven Lactobacillus isolates that showed prominent in-vitro antibacterial activity revealed maximum sequence homology with Lactobacillus fermentum (for six isolates) and Lactobacillus agilis (for one isolate). The in-vitro antibacterial activity results highlighted the need for in-vivo studies in India to establish probiotic potential of canine faecal Lactobacillus species in the near future.

Host-dependent symbiotic efficiency of Rhizobium leguminosarum bv. trifolii strains isolated from nodules of Trifolium rubens

Trifolium rubens L., commonly known as the red feather clover, is capable of symbiotic interactions with rhizobia. Up to now, no specific symbionts of T. rubens and their symbiotic compatibility with Trifolium spp. have been described. We characterized the genomic diversity of T. rubens symbionts by analyses of plasmid profiles and BOX–PCR. The phylogeny of T. rubens isolates was inferred based on the nucleotide sequences of 16S rRNA and two core genes (atpD, recA). The nodC phylogeny allowed classification of rhizobia nodulating T. rubens as Rhizobium leguminosarum symbiovar trifolii (Rlt). The symbiotic efficiency of the Rlt isolates was determined on four clover species: T. rubens, T. pratense, T. repens and T. resupinatum. We determined that Rlt strains formed mostly inefficient symbiosis with their native host plant T. rubens and weakly effective (sub-optimal) symbiosis with T. repens and T. pratense. The same Rlt strains were fully compatible in the symbiosis with T. resupinatum. T. rubens did not exhibit strict selectivity in regard to the symbionts and rhizobia closely related to Rhizobium grahamii, Rhizobium galegae and Agrobacterium radiobacter, which did not nodulate Trifolium spp., were found amongst T. rubens nodule isolates.

Multilocus Genetic Characterization of Lactobacillus fermentum Isolated from Ready-to-Eat Canned Food

The primary mission of the U.S. Food and Drug Administration is to enforce the Food, Drug, and Cosmetic Act and regulate food, drug, and cosmetic products. Thus, this agency monitors the presence of pathogenic microorganisms in these products, including canned foods, as one of the regulatory action criteria and also ensures that these products are safe for human consumption. This study was carried out to investigate the effectiveness of pathogen control and integrity of ready-to-eat canned food containing Black Bean Corn Poblano Salsa. A total of nine unopened and recalled canned glass jars from the same lot were examined initially by conventional microbiologic protocols that involved a two-step enrichment, followed by streaking on selective agar plates, for the presence of gram-positive and gram-negative bacteria. Of the eight subsamples examined for each sample, all subsamples of one of the containers were found positive for the presence of slow-growing rod-shaped, gram-positive, facultative anaerobic bacteria. The recovered isolates were subsequently sequenced at rRNA and gyrB loci. Afterward, multilocus sequence typing (MLST) was performed characterizing 11 additional known MLST loci (clpX, dnaA, dnaK, groEL, murC, murE, pepX, pyrG, recA, rpoB, and uvrC). Analyses of the nucleotide sequences of rRNA, gyrB, and 11 MLST loci confirmed these gram-positive bacteria recovered from canned food to be Lactobacillus fermentum . Thus, the DNA sequencing of housekeeping MLST genes can provide species identification of L. fermentum and can be used in the canned food monitoring program of public health importance.

Identification of oral cavity biofilm forming bacteria and determination of their growth inhibition by Acacia arabica, Tamarix aphylla L. and Melia azedarach L. medicinal plants

ObjectiveBiofilms are complex, multi-species bacterial communities that colonize the oral cavity in the form of plaque and are known to cause dental caries and periodontal disease. Present study demonstrated the potential of three selected medicinal plants against isolated and identified dental biofilm forming strains. MethodsPathogenic bacteria from dental biofilms were isolated, cultured, identified by phylogenetic analysis using PCR-based 16S ribosomal RNA (or 16S rRNA) nucleotide sequences and were analyzed for their biofilm forming capability. The antimicrobial activity of the three important medicinal plant extracts (Acacia arabica, Tamarix aphylla L. and Melia azadirachta L.) was determined against the highest biofilm forming bacteria. ResultsPhylogenetic analysis revealed that the 19 strains belonged to Proteobacteria, Firmicutes and Actinobacteria. Among the 19 isolates, eleven strains were found to possess high biofilm formation capability comparatively and antimicrobial activity assay showed that the selected plants considerably inhibited their growth. Extract from A. arabica stem had strong effect on the ability of bacteria isolated from dental carries as evident by up to 73% reduction in biofilm formation on surface pre-treated with extract from this plant. The same extract also showed tremendous biofilm cleaning potential up to 87% of the biofilm. ConclusionThe results suggested that the extracts of selected medicinal plants could be used for protection against pathogenic dental biofilm causing bacteria and attempts should be taken by pharmaceutical industries to utilize it in dental caring products.

Identification and characterization of a phytoplasma associated with black locust yellow disease in two provinces of Iran

A phytoplasma disease was associated with black locust trees showing yellows, a devastating disease found in different geographical areas of Iran. Infected trees showed yellowing, reduced leaf size, short internodes and proliferation of buds, dieback and decline. The disease was transmitted to healthy black locust and periwinkle plants in greenhouse. DNA extractions were made from midrib of leaf tissues. Nested PCR assays with R16mF2/R16mR1 universal phytoplasma primers detected a 1.4 kb product and an 850 bp product was obtained using Fu5/Ru3 primers in double nested PCR. Phytoplasmas were detected from all symptomatic black locust trees as well as inoculated black locust and periwinkle plants. Analysis of 16S rRNA gene sequences showed that phytoplasmas associated with black locust yellows (BLYp) were related to ‘Candidatus Phytoplasma phoenicium’ (group 16SrIX). Moreover, four 16S rDNA genetic isolates (BLYp-a to -d), distinguished by 1–10 single nucleotide polymorphisms (SNPs), were identified in BLYp population. Virtual RFLP analysis determined that BLYp-a represents a new tentative subgroup within the 16SrIX group; BLYp-b, BLYp-c and BLYp-d were assigned to subgroup 16SrIX-C. Actual RFLP profiles derived from EcoRI, RsaI, HinfI and TaqI enzymes confirmed virtual RFLP subgroup characterization. Phylogenetic analysis showed that BLYp isolates shared a recent common ancestor with some 16SrIX-C phytoplasma strains. Moreover, comparisons of 16S rRNA and SecY gene nucleotide sequence raised the question as to whether BLYp and other 16SrIX-C phytoplasmas identified in Iran are identical or closely related strains. To the best of our knowledge, this is the first report of 16SrIX phytoplasmas infecting black locust.

The new bacterial strain Paenibacillus sp. IB-1: A producer of exopolysaccharide and biologically active substances with phytohormonal and antifungal activities

The bacterial strain IB-1, which exhibits antagonism towards phytopathogens and stimulates the growth of agricultural plants, was isolated from the soil. Analysis of the cultural, morphological, physiological, and biochemical features and nucleotide sequences of the genes 16S rRNA and gyrB, as well as the fatty acid composition, made it possible to attribute the strain IB-1 to the genus Paenibacillus; however, the results did not provide an unambiguous conclusion on its species. The strain Paenibacillus sp. IB-1 possesses nitrogenase activity, the ability to synthesize indoleacetic acid and cytokinin-like compounds, and antagonistic activity towards phytopathogenic fungi, which indicates prospects for its use as a biological product for agricultural purposes. A high-viscous exopolysaccharide was isolated from the cultural fluid of Paenibacillus sp. IB-1. Based on the data from IR and NMR spectroscopy, it was shown to be a heteropolymer comprised of one to four linked α-L-guluronic acid and β-D-mannuronic acid residues. The exopolysaccharide was successfully tested as an adhesive for presowing treatment of barley and wheat seeds with biofungicides.

Tuyển chọn vi khuẩn có khả năng phân huỷ phế phụ phẩm sau thu hoạch quả vải

Bacterial strains which had ability in degrading cellulose were isolated and selected and then used for producing bioproducts to treat litchee postharvest wastes. From 300 samples of natural litchee compost, 98 bacterial strains were isolated. Of which, bacterial strains V19 and V98 were determined dominant cellulase, amylase, and protease enzymatic activities. Both V19 and V98 indicated the significant resistance to antibiotics upto 1000 mg/l culture media. These two strains showed significant growth and extracellular enzymatic in different pH and temperature of culture media. In case of pot experiment, litchee postharvest wastes were decomposed at level 57 - 59% by being applied V19 or V98 bio-product after 35 days (control was 45%). Based on characteristics of culture, morphological, physiological, biochemical, and 16S rRNA nucleotide sequences, V19 was identifield as Bacillus cereus, V98 was Bacillus toyonensis.

Characterization and antimicrobial potential of soil actinobacterium TFA1 isolated from Talakona forest, Andhra Pradesh

The present study reports the characterization and antimicrobial potential of actinobacterial strain TFA1 isolated from Thalakona forest soil, Andhra Pradesh. Phenotypic, cell wall and molecular characteristics of strain TFA1 was studied by adopting standard procedures. Strain TFA1 produced powdery colonies on ISP2 agar medium with aerial and substrate mycelium. Cell wall analysis revealed the presence of LL- DAP and glycine but no sugar. PCR amplification of 16s rRNA gene of strain TFA1 yielded 1200 bp sequence. In 16s rRNA nucleotide sequence analysis, strain TFA1 (accession no KP893923) shows 99% similarity to Streptomyces kurssanoviiNBRC 13192. In preliminary agar plug method, strain TFA1 showed activity against S. aureus, B. cereus and E. coli. Strain TFA1 produced bioactive metabolites in solid media on 3rd day of fermentation whereas in liquid media the production of bioactive metabolite was observed on 5th day of fermentation. The ethyl acetate extract of strain TFA1 showed 14-18 mm inhibition against Gram positive and Gram negative bacterial pathogens.

Molecular Characterization of Anaplasma sp. in Free-Living Gray Brockets (Mazama gouazoubira).

Bacteria in the genus Anaplasma are responsible for diseases in animals and humans. Studies carried out in Brazil have demonstrated that Brazilian deer are able to act as hosts of agents in the family Anaplasmataceae and are possibly potential reservoirs of these pathogens. Molecular and phylogenetic studies have been carried out on samples of two gray brocket specimens (Mazama gouazoubira) from the city of Guarapuava, state of Paraná, Brazil, for the detection of Anaplasma sp. in these animals. Partial nucleotide sequences of the genes 16S rRNA and groESL were used for phylogenetic analyses and compared with other 13 and 17 partial sequences of the respective genes obtained in GenBank. These assessments showed topological incongruence among the trees generated in the phylogenetic analyses. Phylogenetic analysis based on the gene 16S rRNA of the genotypes amplified in the samples of this study was similar to those of A. bovis detected in dogs and wild deer in Japan, whereas studies carried out on gene groESL indicated proximity with sequences of Anaplasma sp. that were also isolated in deer in Japan and allocated in the same clade of partial sequences of A. phagocytophilum. As the 16S rRNA gene is highly conserved, with few polymorphic positions, it may show low reliability for studies on phylogenetic positioning. The present study detected an Anaplasma sp. genotype in two specimens of M. gouazoubira in southern Brazil, which may mean that this agent possibly circulates in deer populations, and demonstrated the need for studies related to the possible role of deer in enzootic cycles of Anaplasmataceae in Brazil.

Prevalence of Methicillin-Resistant Staphylococcus aureus and Other Staphylococcus Species in Raw Meat Samples Intended for Human Consumption in Benin City, Nigeria: Implications for Public Health.

The present study was designed to characterize methicillin-resistant staphylococci from raw meat. A total of 126 meat samples were obtained from open markets between February and April, 2015. Antimicrobial susceptibility testing was carried out using the disc diffusion method. Molecular profiling was conducted using 16S rRNA, mecA, nuc, and PVL gene signatures were detected by polymerase chain reaction assay. Fifty isolates of methicillin-resistant Staphylococcus spp. were detected in 26 (52%) pork, 14 (28%) beef and 10 (20%) chicken samples. The staphylococcal isolates were identified through partial 16S ribosomal ribonucleic acid (16S rRNA) nucleotide sequencing, and BLAST analysis of the gene sequence revealed 98%–100% staphylococcal similarity. All isolates from beef and chicken samples amplified the mecA gene, while 100% of the MRSA isolates amplified the PVL gene. The multidrug resistance profile (resistant to ≥1 antimicrobial agent in ≥3 classes of antimicrobial agents) of the staphylococcal isolates showed that 7 isolates were resistant to methicillin, penicillin, clindamycin, chloramphenicol, trimethoprim-sulfamethoxazole, kanamycin, amoxicillin, cloxacillin, erythromycin, vancomycin, and gentamycin. There was a significant regression effect from the multidrug-resistant profile on the number of isolates (p < 0.05) suggesting a consequence of the dissemination of resistant strains within bacterial populations. The findings of the present study indicate that raw meats in the Benin metropolis were possibly contaminated with pathogenic and multi-drug resistant staphylococci strains and therefore could constitute a risk to public health communities.

Molecular Identification and Diversity of ‘Candidatus Phytoplasma solani’ Associated with Red-leaf Disease ofSalvia miltiorrhizain China

Reddening disease has recently been threatening Salvia miltiorrhiza in China, ranging from 30 to 50%. The main symptoms observed, such as plant stunting, inflorescence malformation, leaf reddening, fibrous roots browning, skin blackening and eventually root rot, are typically associated with phytoplasma infection. The presence of phytoplasmas was demonstrated through phytoplasma-specific PCR, with the expected amplification (1.8 kb) from symptomatic S. miltiorrhiza plants from Shangluo, Shangzhou and Luonan fields in Shaanxi Province of China. The sequences of 16S rRNA, tuf, secY and vmp1 genes amplified from LN-1 phytoplasma shared the closest homologies of 99%, 100%, 99% and 98% with those of the reference strain Candidatus Phytoplasma solani (subgroup 16SrXII-A), respectively. The phylogenetic trees showed that LN-1 phytoplasma clustered with the members of 16SrXII-A group, including Ca. P. solani. Computer-simulated restriction fragment length polymorphism analysis further supported this classification. Diversity analysis showed that all ‘Ca. P. solani’ strains identified from the three different regions examined shared 100% identical 16S rRNA, tuf, secY and vmp1 nucleotide sequences. To the best of our knowledge, this is the first report of phytoplasma infecting the medicinal plant of S. miltiorrhiza. The results demonstrate that ‘Ca. P. solani’ is the presumptive aetiological agent of S. miltiorrhiza reddening disease in China.

Effect of metal ions and petrochemicals on bioremediation of chlorpyrifos in aerobic sequencing batch bioreactor (ASBR).

Application of chlorpyrifos (CP) has increased its environmental concentration. Increasing CP concentration has increased chances of adverse health effects. Its removal from environment has attained researcher's attention. CP degrading bacterial strains were isolated from wastewater and agricultural soil. Finally, selected five bacterial strains were identified using 16S rRNA nucleotide sequence analysis as Pseudomonas kilonensis SRK1, Serratia marcescens SRK2, Bacillus pumilus SRK4, Achromobacter xylosoxidans SRK5, and Klebsiella sp. T13. Interaction studies among bacterial strains demonstrated possibility for development of five membered bacterial consortium. Biodegradation potential of bacterial consortium was investigated in the presence of petrochemicals and trace metals. About 98% CP removal was observed in sequencing batch reactors at inoculum level, 10%; pH, 7; CP concentration, 400mgL-1, and HRT, 48h. Experimental data has shown an excellent fit to first order growth model. Among all petrochemicals only toluene (in low concentration) has stimulatory effect on biodegradation of CP. Addition of petrochemicals (benzene, toluene, and xylene) in high concentration (100mgL-1) inhibited bacterial activity and decreased CP removal. At low concentration i.e., 1mgL-1 of inorganic contaminants (Cu, Hg, and Zn) >96% degradation was observed. Addition of Cu(II) in low concentration has stimulated CP removal efficiency. Hg(II) in all concentrations has strongly inhibited biodegradation rate except at 1mgL-1. In simulated pesticide, wastewater CP removal efficiency decreased to 77.5%. Outcomes of study showed that both type and concentration of petrochemicals and trace metals influenced biodegradation of CP.

A new species of the rare genus Priscomilitaris from the Seto Inland Sea, Japan (Crustacea, Amphipoda, Priscomilitaridae).

A new species of the priscomilitarid amphipod, Priscomilitaris heike, from the Seto Inland Sea, Japan, is named and described. This new species is the third species of Priscomilitaridae and the second species of Priscomilitaris. Additionally, nucleotide sequences of nuclear 28S rRNA and histone H3 as well as mitochondrial cytochrome c oxidase subunit I from its holotype were determined. Priscomilitaris heike sp. n. is distinguished from its congener, Priscomilitaris tenuis Hirayama, 1988, by having deep antennal sinus, long flagellar article 1 of antennae 1 and 2, long mandibular palp article 2, 10 robust setae on outer ramus of maxilla 1, and rounded epimeral plates. A key to the species of Proscomilitaridae is provided.

STATISTICAL ANALYSIS OF ACTINOMYCETES ISOLATED FROM THE HARIDWAR REGION OF UTTARAKHAND (INDIA)

Statistical analysis of Actinomycetes isolated from biodegraded and non biodegraded building materials at Haridwar region of Uttarakhand (India). The concentrations of viable actinomycetes varied between 50-250 x104 and 5-150x104 cfu/g in the biodegradable and non degradable buildings, respectively. In all studies, the concentrations of viable actinomycetes were higher in the index (biodegradable) buildings than in the reference (non biodegradable) buildings. Phylogenetic characterization of the isolates based on 16S rRNA gene sequencing supported their assignment to 18 different actinomycete genera representing seven different suborders. The result exhibited similarity 91% with 10 strains from the uncultured known species of Streptomyces, Nocardia and Micromonospora. The 16S rRNA nucleotide sequence of Streptomyces, Nocardia and Micromonospora consisted of 749 bp each and the G-C content was 70%. These results show a high diversity of actinomycetes associated with buiding materials and the detection and identification of this group of organisms is extremely important for the deteriogenic process and the development of control methods. Keywords: Actinomycetes; Nocardia, Micromonospora, building materials, statistical phylogenetic analysis

Detection of Methicillin-Resistant Staphylococci Isolated from Food Producing Animals: A Public Health Implication.

The emergence of antibiotic-resistant bacteria in food animals is a potential public health concern. Staphylococci are a significant opportunistic pathogen both in humans and dairy cattle. In the present study, the genotypic characterization of methicillin-resistant staphylococcal strains recovered from dairy cattle in a rural community (Okada, Edo State, Nigeria) was investigated. A total of 283 samples from cattle (137 milk samples and 146 nasal swabs) were assessed between February and April 2015. Antimicrobial susceptibility was performed by Kirby-Bauer disc diffusion method. Polymerase chain reaction (PCR) assay was employed for the detection of 16S rRNA, mecA and Panton-Valentine Leucocidinis (PVL) genes. The staphylococcal strains were identified through partial 16S ribosomal ribonucleic acids (rRNA) nucleotide sequencing, and Basic Local Alignment Search Tool (BLAST) analysis of the gene sequence showed that the staphylococcal strains have 96%–100% similarity to Staphylococcus aureus (30), S. epidermidis (17), S. haemolyticus (15), S. saprophyticus (13), S. chromogenes (8), S. simulans (7), S. pseudintermedius (6) and S. xylosus (4). Resistance of 100% was observed in all Staphylococcus spp. against MET, PEN, CLN, CHL and SXT. Multi-drug resistant (MDR) bacteria from nasal cavities and raw milk reveals 13 isolates were MDR against METR, PENR, AMXR, CLNR, CHLR, SXTR CLXR, KANR, ERYR, and VANR. Of all isolates, 100% harboured the mecA gene, while 30% of the isolates possess the PVL gene. All S. aureus harboured the PVL gene while other Staphylococcus spp. were negative for the PVL gene. The presence of methicillin-resistant Staphylococcus spp. isolates in dairy cattle is a potential public health risk and thus findings in this study can be used as a baseline for further surveillance.

Pathogenicity of Aeromonas hydrophila isolated from the Malaysian Sea against coral (Turbinaria sp.) and sea bass (Lates calcarifer).

A study was carried out to determine the pathogenicity (hemolytic activity) on corals (Turbinaria sp.) and sea bass (Lates calcarifer) of Aeromonas hydrophila from water, sediment, and coral. Samples were collected from coastal water and coral reef areas. One hundred and sixty-two isolates were successfully isolated. Out of 162, 95 were from seawater, 49 from sediment, and 18 from coral. Sixteen isolates were picked and identified. Isolates were identified using a conventional biochemical test, the API 20NE kit, and 16S rRNA nucleotide sequences. Hemolytic activity was determined. Out of 16 isolates, 14 isolates were β-hemolytic and two isolates were non-hemolytic. Corals infected with A. hydrophila suffered bleaching. Similar effect was observed for both hemolytic and non-hemolytic isolates. Intramuscular injection of A. hydrophila into sea bass resulted in muscular bleeding and death. Higher infection rates were obtained from hemolytic compared to non-hemolytic strains of A. hydrophila isolates.

Antimicrobial resistance of methicillin-resistant staphylococci isolated from food producing animal

Background: The emergence of antibiotic-resistant microorganisms in food-animal environments poses a public health concern. Staphylococcal is an important opportunistic pathogen both in humans and in dairy cattle. It can be transferred between animals and humans either by direct contact or via the food chain. This study aimed to evaluate the phenotypic and genotypic characterization of methicillin-resistant staphylococci from dairy cattle in a rural community, Okada, Edo State, Nigeria. Methods & Materials: A total of 283 samples from cattle (137 milk samples and 146 nasal swabs) were assessed between February and April 2015. Phenotypic reactions were conducted using Modified Hodge Test (MHT), and Double Disk Synergistic Test (DDST). Antimicrobial susceptibility was performed by Kirby-Bauer disk diffusion method according to CLSI standard. Polymerase chain reaction (PCR) assay were employed for the detection of 16S rRNA, mecA, nuc and PVL genes. Results: The Staphylococcal was identified through partial 16S ribosomal ribonucleic acids (rRNA) nucleotide sequencing and BLAST analysis of the gene sequence showed the staphylococcal to have 98% - 100% similarity to Staphylococcus aureus (30), S. epidermidis (17), S. haemolyticus (15), S. saprophyticus (13), S. chromogenes (8), S. simulans (7), S. intermedius (6) and S. xylosus (4). MHT showed 90% and 96% of the isolates from nasal and raw milk respectively, revealed carbapernemase activity. Also, 4% of the isolates from the nasal cavity and 8% of the isolates from raw milk were positive to DDST, thus revealing metallo-β-lactamases production. Resistance of 100% was observed in all Staphylococcus spp., against MET, PEN, CLN, CHL and SXT. Multidrug resistant from nasal cavity and raw milk reveals 13 isolates against METR, PENR, AMXR, CLNR, CHLR, SXTR CLXR, KANR, ERYR, and VANR. Of all isolates, 100% harboured the mecA, 46% of the isolates nuc genes while 30% of the isolates possess the PVL gene. All S. aureus isolates harboured the PVL gene while other Staphylococcus spp., were negative to the PVL gene. S. aureus were 90% positive to the nuc gene. Conclusion: The presence of methicillin-resistant Staphylococcus isolates in dairy cattle is a potential public health risk and thus the findings in this study can be used as a baseline for further surveillance.