Microbial Quality of Preserved Sardines Sold in Mombasa

The research was conducted in five different market centres in Mombasa to investigate microbiological quality of sardines preserved using different techniques. A total of thirty (30) sardines were randomly sampled and purchased for analysis of pathogenic and spoilage microorganisms. The microbial load (bacteria and moulds) were determined using pour plate technique. The results showed that out of the six preservation techniques (smoking, drying, salting, freezing, frying and canning) sardines preserved using five of the techniques (83.3%) were contaminated with Vibrio species while two techniques (33.3%) allowed the growth of Salmonella species. Other bacterial species found in preserved sardines included Micrococcus, Staphylococcu and Listeria species among many others. There were also five species of fungi isolated from preserved sardines including Aspergillus species which is of clinical importance. The presence of pathogenic bacteria and fungi of clinical importance are some of the possible health risks that may be associated with consumption of preserved sardines sold in Mombasa. This may possess real health problems unless measures are put in place to prevent microbial contamination of preserved sardines. The total microbial contamination of sardine samples were compared to International Commission on Microbiological Specifications for Foods (ICMSF, 1998) shown in appendix I. Based on total microbial considering bacteria and fungi, smoked sardines had 3.57 x 103, dried 5.096 x 103, salted 2.528 x 103, frozen 3.74 x 102, fried 3.72 x 102 and canned 78 cfu. This showed that dried sardines were the most contaminated while canned were least contaminated

Antimicrobial resistance and plasmid profiles of Aeromonas hydrophila isolated from River Njoro, Kenya

The purpose of this study was to investigate the presence of Aeromonas hydrophila at commonly used water collection points on the River Njoro and to determine the in-vitro antimicrobial susceptibility and plasmid profiles of isolates. In total, 126 samples were collected and 36.5% of them were positive for A. hydrophila. The A. hydrophila were recovered on membrane filters, cultured on Trypticase Soy agar, Bile aesculin agar and Aeromonas Medium agar. They were further characterized using cytochrome oxidase and API 20E tests. Detection of drug susceptibility was determined using modified disc diffusion method to ampicillin (25 ìg), cefaclor (30 ìg), ceftizoxime (30 ìg), cefixime (5 ìg), cefazidime (30 ìg), gentamicin (200 ìg), streptomycin (25 ìg), chloramphenicol (50 ìg), nalidixic acid (30 ìg) and ciprofloxacin (1 ìg). Most of the isolates showed multi-drug resistance to two or more antibiotics. Chloramphenicol, nalidixic acid, ciprofloxacin, cefazidime and cefixime were the most sensitive drugs with 100% efficacy whereas ampicillin, cefaclor and streptomycin were the most resistant drugs having 100, 67 and 50 resistance, respectively. There was low resistance against ceftizoxime (16.7%) and gentamicin (23.3%). These results indicates that all A. hydrophila isolated from River Njoro had complete resistance to ampicillin and showed variable resistance to cefaclor, streptomycin, gentamycin and ceftizoxime. R-plasmids were extracted from multi-drug resistance strains and separated by agarose gel (0.8%) electrophoresis for profiling. Plasmid profiling revealed that most of the multi-drug resistant isolates contained one plasmid of 21.0 kb. Although some strains exhibited different antimicrobial resistance patterns, all of their plasmids were of the same size (21.0 kb). However, there were no plasmids in the antimicrobial sensitive isolates. This study also indicates that plasmid 21.0 kb is common in A. hydrophila and is important for antimicrobial resistance and virulence. Further studies are required to ascertain the role of this plasmid as a virulence marker.Key words: Aeromonas hydrophila, antimicrobial resistance, plasmid profile

Antimicrobial resistance and plasmid profiles of Aeromonas hydrophila isolated from River Njoro, Kenya

The purpose of this study was to investigate the presence of Aeromonas hydrophila at commonly used water collection points on the River Njoro and to determine the in-vitro antimicrobial susceptibility and plasmid profiles of isolates. In total, 126 samples were collected and 36.5% of them were positive for A. hydrophila. The A. hydrophila were recovered on membrane filters, cultured on Trypticase Soy agar, Bile aesculin agar and Aeromonas Medium agar. They were further characterized using cytochrome oxidase and API 20E tests. Detection of drug susceptibility was determined using modified disc diffusion method to ampicillin (25 μg), cefaclor (30 μg), ceftizoxime (30 μg), cefixime (5 μg), cefazidime (30 μg), gentamicin (200 μg), streptomycin (25 μg), chloramphenicol (50 μg), nalidixic acid (30 μg) and ciprofloxacin (1 μg). Most of the isolates showed multi-drug resistance to two or more antibiotics. Chloramphenicol, nalidixic acid, ciprofloxacin, cefazidime and cefixime were the most sensitive drugs with 100% efficacy whereas ampicillin, cefaclor and streptomycin were the most resistant drugs having 100, 67 and 50 resistance, respectively. There was low resistance against ceftizoxime (16.7%) and gentamicin (23.3%). These results indicates that all A. hydrophila isolated from River Njoro had complete resistance to ampicillin and showed variable resistance to cefaclor, streptomycin, gentamycin and ceftizoxime. R-plasmids were extracted from multi-drug resistance strains and separated by agarose gel (0.8%) electrophoresis for profiling. Plasmid profiling revealed that most of the multi-drug resistant isolates contained one plasmid of 21.0 kb. Although some strains exhibited different antimicrobial resistance patterns, all of their plasmids were of the same size (21.0 kb). However, there were no plasmids in the antimicrobial sensitive isolates. This study also indicates that plasmid 21.0 kb is common in A. hydrophila and is important for antimicrobial resistance and virulence. Further studies are required to ascertain the role of this plasmid as a virulence marker

Antitubercular and phytochemical investigation of methanol extracts of medicinal plants used by the Samburu community in Kenya

Purpose: To determine the potential benefits of nine medicinal plants used by the Samburu community for the treatment of tuberculosis. Methods: The extract was tested against four strains of Mycobacteria namely; Mycobacterium tuberculosis (Mtb), M. Kansasii (Mk), M. fortuitum (Mf), and M. smegmatis (Ms) using BACTEC MGIT 960 system. The crude extracts were also analyzed for the presence of phytochemical constituents. Results: Both the extracts of Scadoxus multiflorus and Acacia nilotica showed strong antimycobacterial activity against the four tuberculosis-causing strains. Eurphobia scarlatina was the most active against both the slow (Mtb and Mk) and the fast (Mf and Ms) growers with Zero GUs at 0.5mg/ml. Phytochemical screening indicated presence or absence of tannins, saponins and flavonoids, terpenoids, cardiac glycosides and alkaloids in the extracts. Conclusion: The data suggest that some of the methanol extracts could be a rich source of antituberculosis agents. The results further show that there is some merit in the use of some of the plants studied in alternative medical practice. Pharmacological and toxicological studies of the active plants are still under investigation

Antibacterial Activity of Tabernaemontana Stapfiana Britten (Apocynaceae) Extracts

Antibacterial and phytochemical screening of methanolic, sequential extracts (hexane, dichloromethane, ethyl acetate and methanol) and alkaloid rich fractions of Tabernaemontana stapfiana Britten was carried out. The phytochemical screening showed the presence of alkaloids, flavonoids, coumarins, tannins and saponins that have been associated with antimicrobial activity. The stem and root bark methanolic extracts showed good activity against the bacterial strains used including the multiple drug resistant Staphylococcus aureus strain with minimum inhibitory concentrations ranging from 15.6 to 500 µg/ml and minimum bactericidal concentrations ranging from 31.25 to 500 µg/ml. The sequential extracts of the root and stem bark had high antimicrobial activity with minimum inhibitory concentrations (MICs) ranging between 3.9 and 250 µg/ml and minimum bactericidal concentrations (MBCs) ranging between 7.8 and 500 µg/ml against the tested microorganisms. The dichloromethane extract of the alkaloid rich fractions however exhibited reduced antibacterial activities as compared to methanol and sequential extracts but the dichloromethane:methanol (4:1) mixture showed high activity with MICs ranging between 15.6 and 250 µg/ml. These antibacterial efficacy studies suggest that Tabernaemontana stapfiana Britten could be a source of antibacterial agents