Isolation of Listeria monocytogenes recovered from some ready-to-eat foods sold in Kano, north-western Nigeria

Listeria monocytogenes and other Listeria species were isolated from some ready-to-eat foods sold in Kano metropolis. The method of United States Food and Drug Administration, Center for Food Safety and Applied Nutrition (FDACFSAN) was adopted in the isolation of the organism. A total of 336 food samples were screened. This included 29 beef burger, 30 yoghurt, 32 locally fermented fresh milk (nono), 34 cabbage, 45 grilled meat (tsire), 48 lettuce, 55 meat-pie and 63 roasted meat (balangu) samples. Samples were collected from December 2012 to March 2013. From these samples 38 (11.3%) yielded Listeria species. Six isolates (1.8%) were found to be L. monocytogenes, 31 (9.2%) were found to be L. ivanovii and 1(0.3%) was L. seeligeri. Out of the 38 isolates, 7 (18%) were from ‘balangu’, 9 (24%) cabbage, 14 (37%) lettuce, 5 (13%) meat pie and 3 (8%) ‘tsire’ samples. L. monocytogenes was isolated from 3 lettuce samples (50%), 2 ‘balangu’ samples (33%) and 1 meat-pie sample (17%). On the other hand, L. monocytogenes was not isolated from ‘tsire’, beef burger, ‘nono’ and yoghourt samples. This study showed the presence of the organism in Kano, which could pose a threat of outbreak or sporadic cases of listeriosis with high morbidity and mortality rates.Keywords: Isolation, Listeria monocytogenes, Ready-to-eat foods, Kano

Bacteriological and Physcio – Chemical Evaluation of Water Treated with Seed Powder of Moringa oleifera

Bacteriological and physico-chemical evaluation of water coagulated with Moringa oleifera seed powder preparations on Challawa river water intake station was conducted for a period of ten months (November, 2004 – August, 2005). Four graded doses of M. oleifera seed powder suspension (800mg/L, 880mg/L, 960mg/L and 1040mg/L) were employed for water treatment using standard methods. Results of bacteriological analysis on raw water samples using 9 – tube, 3 dilution technique, coliform estimations ranged between 150MPN/100ml and 1100MPN/100MPN and faecal coliform 86 MPN/100ml and 171 MPN/100ml, while M. oleifera treated water samples had counts ranging between 43MPN/100ml and 460 /100ml as well as 33MPN/100ml and 171 MPN/100ml for coliforms and faecal coliforms respectively. Aerobic mesophilic bacterial count on raw and M. oleifera treated water samples showed a range of 2.5 x 103 cfu/ml to 9.3x103cfu/ml and 1.0x101cfu/ml to 9.3 x 102 cfu/ml respectively.  Escherichia coli, Proteus spp, Salmonella spp, Klebsiella spp and Shigella spp were detected in the raw water. Results of physico – chemical parameters of raw water samples from Challawa showed that turbidity ranged between 384NTU and 898 NTU, alkalinity 45mg/L and 70mg/L, pH 6.8, temperature 18oC and 25oC, sulphate ions 89mg/L and 195mg/L, nitrate ions 45mg/L and 162.5mg/L, phosphate ions 0.92 mg/L and12.25mg/L Dissolved Oxygen (DO) 5.6mg/L and 38.4mgl, 5 – day Biological Oxygen Demand (BOD5) 0.8mgl and 12mg/L. M. oleifera treated water samples had values for turbidity fluctuating between 14 NTU and 25NTU, alkalinity 30 mg/L and 43 mg/L, pH 7.0 and 7.2, temperature 20oC and 27oC, sulphate ions 19mg/L and 68mg/L, nitrate ions 24 mg/L and 68.0mg/L and phosphate ions 0.33 mg/L and 1.62mg/L. Statistical analysis of the results revealed significant difference between the varying seed powder doses in relation to bacterial recovery and most of the physico – chemical parameters at P<0.05. The implications of the results are discussed in relation to water sanitation and human health and some recommendations presented.Keywords: Bacteriology, Challawa, Physico-chemistry, Seed, Water treatmen

Phytochemical Screening, Antibacterial and Toxicological Activities of Acacia Nilotica Extracts

The phytochemical screening, antibacterial and toxicological activities of extracts of the leaves, stem bark and roots of Acacia nilotica were investigated. The phytochemical analyses according to standard screening tests using conventional protocols revealed the presence of tannins and sterols in the leaves stem barks and roots of the plant. Alkaloids were detected only in the leaves. Glycosides, saponins, resins and flavonoids were not detected in the plant. In-vitro agar-diffusion sensitivity tests of crude extract fractions of the plant extracts using ethanol, chloroform, methanol, petroleum ether, water and ethyl acetate were investigated on nine bacterial isolates. The extract fractions generally exhibited marked antibacterial activities on Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhi, Shigella dysenteriae Staphylococcus aureus and Escherichia coli except on Streptococcus pneumoniae and Streptococcus pyogenes. All the leaves extract fractions of the plant exhibited weak or no antibacterial activity on the bacterial isolates tested but the stem bark and root extracts generally exhibited strong antibacterial activities on them. The minimum inhibitory concentration and minimum bactericidal concentration studies revealed that some bacterial isolates were inhibited at concentrations of about 12.5mg/ml and 50mg/ml and killed at concentrations of about 100mg/ml and 400mg/ml. Toxicity studies of the ethanol extracts revealed that they  exhibited no significant toxicity (LD50 of 123.86μg/ml and312.55μg/ml) against Artemia salina . These results suggest that the plant may not be toxic to man and could be a potential source of novel antibacterial compound.Keywords: Phytochemical Screening, Antibacterial Activity, Toxicological Activity Acacia nilotica, Extract

Phytochemical Screening, Antibacterial and Toxicological Activities of Acacia Senegal Extracts

The phytochemical screening, antibacterial and toxicological activities of extracts of the stem bark of Acacia senegal were investigated. The phytochemical analyses according to standard screening tests using conventional protocols revealed the presence of tannins, saponins and sterols in the stem bark of the plant. Alkaloids, glycosides and flavonoids were not detected in the plant. In-vitro agar diffusion sensitivity tests of crude extract fractions of the plant extracts using ethanol, chloroform, methanol, petroleum ether, water and ethyl acetate were investigated on nine bacterial isolates. Ethanol and methanol stem bark extracts exhibited antibacterial activity on Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhi, Shigella dysenteriae and Escherichia coli except on Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus pyogenes. The other extract fractions showed no activity on the bacterial isolates at the concentration used. The minimum inhibitory concentration and minimum bactericidal concentration studies revealed that some bacterial isolates were inhibited at concentrations of about 50mg/ml and killed at 400mg/ml. Toxicity studies of the ethanol extracts revealed that they exhibited no significant toxicity (LC50 of 100μg/ml) against Artemia salina . These results suggest that the plant may not be toxic to man and could be a potential source of novel antibacterial compound

Enumeration, Isolation and Antibiotic Susceptibility Profile of Bacteria Associated With Mobile Cellphones in a University Environment

A study was carried out between February and March, 2012, to enumerate, isolate and identify bacteria associated with mobile cell phones in a University environment. This was with a view to determining the bacterial load and their susceptibility pattern to some commonly-used antibiotics. Samples were collected from mobile cell phones of staff, marketers and students in Bayero University, Kano, Nigeria using aseptic swab technique. A total of thirty-five (35) mobile phones were randomly sampled from the following study groups: 10 University staff, 12 marketers and 13 students. For each mobile phone, two sterile swabs moistened with normal saline were rotated over the surface of both sides of the mobile phone and soaked in 10 ml peptone water. Enumeration of the bacterial counts was carried out using pour-plate technique while the bacterial isolates wereidentified using cultural, morphological and biochemical techniques. The results showed that marketers, students and University staff had the overall mean aerobic mesophilic bacterial counts of 5.25 x 102, 4.48 x 102 and 2.50 x 102 cfu/ml respectively. Twenty-eight bacterial isolates belonging to four genera: Escherichia coli 7(25.0%), Staphylococcus aureus 15(53.6%), Salmonella species 2(7.1%) and Klebsiella species 4(14.3%) were identified. Generally, S. aureus was the most isolated with 15(53.6%) while the least was Salmonella species with only 2(7.1%). Antibiotic susceptibility testing of the isolates indicated that S. aureus species had the highest susceptibility of 14(93.3%) against cipfloxacin while Salmonella species had 1(50.0%) against augmentin whereas Klebsiella species had 1(25.0%) each against gentamycin and streptomycin. On the other hand, Salmonella species was not susceptible to gentamycin, perfloxacin and streptomycin each with 0(0.0%). Overall susceptibility was highest against ciprofloxacin with 24(85.7%) while the least was recorded against  gentamycin with 6(21.4%). The identified bacteria have pathogenic potential and hence their presence on the cell phones surfaces could serve as a source of cross-transmission of bacterial infections in the University community and its environs.Keywords: Bacteria, Contamination, Cell phones, Susceptibility profile, Antibiotics, University

Physico-chemical, sensory and microbiological qualities of yoghurt brands sold in Kano metropolis, Nigeria

This study was conducted to evaluate the physico-chemical, sensory and microbiological qualities of some yoghurt brands sold in Kano Metropolis using standard procedures. The physico-chemical characteristics (viscosity, specific gravity, pH, titratable acidity, fat content) and Sensory properties (color, flavor, smell) were determined using the method of the Association of Official Analytical Chemists. The microbiological evaluations were based on the Aerobic mesophilc bacterial, Coliform, Escherichia coli, fungal counts as well as the detection of Staphylococcus aureus and Salmonella sp. using the method of Food and Agricultural Organization and the result presented. Two of the pathogenic strains S. aureus and Salmonella sp. were not isolated in any of the yoghurt samples analyzed. However, mesophilic bacteria, Coliform, Escherichia coli and fungi were positive in some samples. The results of chemical analysis showed no significant differences (p>0.05) between yoghurt samples. Organoleptically, sample YB5 was more significantly of better quality than the rest in terms of its color (7), its flavor (9) and had a significantly higher overall acceptability (p<0.05). The microbial load of all the yoghurt samples except for yoghurt samples (YB3, YB4, YB6 and YB7) microbiologically falls within the acceptable local and international standards.Keywords: Microbiological, Yoghurt, Physico-Chemical, Sensory evaluation, Kano – Nigeria

Prevalence of extended spectrum &#946-lactamases (ESBLs) among clinical Enterobacteriaceae isolates obtained from private diagnostic laboratory in Kano - Nigeria

One hundred Gram negative bacterial isolates were collected from a private diagnostic center and identified by subjecting the isolates to biochemical tests using standard procedures. Confirmed Enterobacteriaceae isolates were further subjected to screening for extended spectrum â-lactamases (ESBLs) production using Clinical Laboratory Standards Institute (CLSI) breakpoint and Double Disc Synergy Test (DDST). Standard discs of Augmentin (AUG 30 ìg) {Optudisc} and Ceftriaxone (CXM 30 ìg) {Medireich} and Ceftazidime (CAZ 30 ìg) {Glaxo-Smithkline} were used in the screening. The results of CLSI breakpoint test showed that 87% were ESBLs producers viz: Citrobacter fruendii (3), Escherichia coli (46), Klebsiella pneumoniae (13), Morganella morganii (1), Proteus vulgaris (23) and Salmonella typhi (1) while that ofconfirmed ESBLs producers using DDST was 49%. These included Citrobacter fruendii (2), Escherichia coli (25), Klebsiella pneumoniae (7), Morganella morganii (1), Proteus vulgaris (13) and Salmonella typhi (1). The implication of the results is discussed

Evaluation of Critical Control Points (CCPS) in the Production of ‘Daddawa’ (African Locust Bean Cake) in Dawakin –Tofa Local Government area, Kano State, Nigeria

Hazard analysis and critical control point (HACCP) was carried out during the production of African locust bean seeds condiment (Daddawa) in a location that specialized in it’s manufacturing namely Kwanar – yandaddawa (Dawakin – Tofa Local Government Area) Kano State, Nigeria. The analyses consisted of determination of the aerobic, anaerobic mesophilic bacterial, staphylococcal and fungal counts. In addition, detection of E. coli 0157: H7, Staphylococcus aureus and Clostridium perfringens on the raw seeds before processing and the processed daddawa were also carried out. The raw seeds, processed seeds, production stages and additives had high total microbial count in the range of 109 - 1011cfu/g, which is above the maximum acceptable limit of 105cfu/g. Bacteria isolated and biochemically characterized were Staphylococcus spp, Clostridium perfringens and E. coli 0157: H7. Mucor and Rhizopus were the fungal genera frequently isolated from most of the samples with Aspergillus fumigatus least isolated. Clostridium botulinum was not isolated at Kwanar yandaddawa. The raw seeds, sand used in dehauling, diluents, pawpaw leaves used as additives as well as final molding, comparing (tabletting) and display for sale to consumers are therefore regarded as a critical control points.Keywords: Aerobes, anaerobes, E. coli 0157: H7, Critical Control Points

Seasonal and Spatial Variations in Water Quality and Its Ecological Implications on Challawa River, Nigeria

The water quality of Challawa River, Kano, Nigeria at three sites was investigated for a period of eighteen months (January, 2005 - June, 2006). Results obtained showed some degree of variations along the river course. The pH, colour, temperature, bicarbonate and turbidity valuesincreased from sample site I (upstream), through site III (downstream) of the river. Levels of dissolved oxygen and phosphate decreased down the stream while biochemical oxygen demand, chemical oxygen demand, electrolytic conductivity, nitrate and sulphate fluctuated between sites. Significant differences (P < 0.05) between both sites and seasons for colour, pH, temperature, electrolytic conductivity, bicarbonate and sulphate exist while no significant difference (P > 0.05) was observed on both sites and seasons for turbidity, nitrate and phosphate. However, dissolved oxygen, biochemical oxygen demand and chemical oxygen demand were significantly different (P < 0.05) only between seasons. The implications of the results were discussed.Keywords: Physico-chemical quality, seasonal, spatial, variation, Challawa River, Kano

Sero-Prevalence of Cytomegalo Virus Antibodies in Pregnant Women Attending Two Selected Hospitals in Sokoto State, North-Western Nigeria

Infection with cytomegalo virus (CMV), especially in pregnancy may cause pregnancy complications such as congenital infection, non-hereditary deafness, intrauterine growth restriction and other high defects. This study was to evaluate the prevalence of CMV in pregnant women attending Antenatal Clinics at Maryam Abacha Women and Children Hospital (MAWCH) and Sokoto Specialist Hospital (SSH). The study enrolled 90 pregnant women (age range: 16-45 years old) and data on demographic and life styles obtained using structured questionnaire. Serum samples were assayed using CMV Ig-G EIA kit. Out of the 90 pregnant women examined, 88(97.8%) had IgG protective antibodies to CMV while 2(2.2%) did not have protective antibodies. The prevalence rate of 2.20% was obtained in pregnant women that did not have the protective CMV IgG antibodies and were in the age range of 16-30 years old. They were also found to be in their second trimester, which could have increased the risk of intrauterine transmission. The risk factors for CMV were observed to have been significantly (P > 0.05) correlated with the socioeconomic status, the levels of CMV Ig-G antibodies, stage of pregnancy as well as the symptoms of pregnancy complications observed in the study population while they were insignificant (P < 0.05) in the case of number of previous pregnancies. The outcome of effects on the fetus was usually fatal and irreversible. Therefore, all pregnant women should scrupulously consistently adhere to routine infection control precautions. Keywords: Cytomegalo virus, Pregnant women, sero-prevalence, Sokoto