Multidrug resistance patterns and multiple antibiotic resistance index of salmonella species isolated from Waste Dumps in Zaria Metropolis, Nigeria

ABSTRACT: Several items containing residual antimicrobial agents are disposed of in dumpsites, placing a pressure on the microbial flora and a potential for development of resistance in these microorganisms. Multidrug resistance patterns and multiple antibiotic resistance index of Salmonella spp. isolated from waste dumps in Zaria Metropolis were thus assayed in this study using one hundred and twelve (112) soil samples collected from four waste dumpsites located in Sabon-Gari, Samaru, Tudun-Wada and Zaria City. Salmonella spp. were isolated by culture methods on selective media and characterized using a series of biochemical tests. The isolates were confirmed using microgen identification kits. Results were statistically analysed using percentages. The antibiotic resistance patterns were determined, using the disc-diffusion method. Ten antibiotics belonging to eight different classes, namely B-lactams, aminoglycosides, tetracycline, cephalosporins, fluoroquinolone, Nitrofurantoins, sulphonamides, and phenicols were tested. The result of the study revealed that 57.2% of the isolates exhibited multidrug resistance (MDR) taken as resistance to four or more antibiotics tested. On the other hand, all the isolates showed 100% susceptibility to Chloramphenicol (30µg) and Gentamicin (30µg) while 76.2% had Multiple Antibiotic Resistance (MAR) Index of 0.2 and above. The isolates showing resistance to the highest number of antibiotics were obtained from refuse dumpsites in Zaria City while an isolate from Sabon-Gari was found to be resistant to six antibiotics. These results could be indicative of possible disposal of these drug residues in the waste dump locations making them hot spots for development of resistance

'Prevalence and antimicrobial susceptibility of Listeria monocytogenes and methicillin-resistant Staphylococcus aureus strains from raw meat and meat products in Zaria, Nigeria.

UNLABELLED: The bacterial genera Listeria and Staphylococcus have been frequently isolated from food products and are responsible for a number of animal and human diseases. The aim of the study was to simultaneously isolate and characterize L. monocytogenes and Staphylococcus species from 300 samples of raw meat and meat products, to determine the susceptibility of the organisms to commonly used antimicrobial agents and to determine the presence of haemolysin A (hyl) virulence gene in L. monocytogenes and staphylococcal cassette chromosome mecA (SCCmec) gene in the Staph. aureus isolates using PCR. Of the 85 Listeria isolates tested, 12 L. monocytogenes were identified and tested for their sensitivity to 14 antimicrobial agents. All the 12 isolates (100%) were resistant to nine antimicrobial agents, but however sensitive to gentamicin. Only one isolate was found to harbour the hylA gene. Twenty-nine isolates were confirmed as Staph. aureus by the Microbact 12S identification system and were all presumptively identified as methicillin-resistant Staph. aureus species using oxacillin-resistant Staph. aureus basal medium (ORSAB). The 29 Staph. aureus isolates were tested for their sensitivity to 16 antimicrobial agents, and 11 were resistant to methicillin. None of the 11 Staph. aureus isolates harboured the methicillin resistance, mecA gene. SIGNIFICANCE AND IMPACT OF THE STUDY: Listeria monocytogenes and Staphylococcus aureus are important agents of foodborne diseases. Occurrence of these infectious agents was established in meat and meat products in Zaria, Nigeria. Majority of isolates obtained from this study, displayed multidrug resistance to commonly used antimicrobial agents, including methicillin resistance among the Staph. aureus isolates. The potential virulence of L. monocytogenes found in ready-to-eat food was documented by the carriage of hly A gene by one of the isolates. A different mechanism of methicillin resistance or different homologue of mec A gene may be circulating among Nigerian isolates.

Asymptomatic Giardiasis and Nutritional Status of Children in Two Local Government Areas in Kaduna State; Nigeria

Giardiasis is found throughout the world but more prevalent in developing countries. The present study utilised ELISA coproantigen to determine the prevalence of Giardia lamblia in stool samples of children in day-care centres; nursery and primary schools in two Local Government Areas; Sabon-Gari and Zaria; in Kaduna State; Nigeria. Of 374 samples examined; 150 (41.45) were positive for Giardia lamblia. The prevalence of giardiasis was higher in males (50.3) than females (49.7). There was no significant difference in the level of infection in both sexes (p = 0.808). The highest prevalence of asymptomatic giardiasis was in the age group 3-5 years (32.9) while the lowest was in the 0-2 years (11.6). There was no significant difference in the prevalence of the disease between the age groups (p = 0.414). There was association between asymptomatic giardiasis and wasting (p = 0.030; ANOVA). There was also a positive association between asymptomatic giardiasis and Body Mass Index (p = 0.024; ANOVA) indicating malnutrition. In this study; giardiasis was a predictor of wasting and malnutrition in Sabo-Gari Local Government Area. It is therefore recommended that parents or guardians should provide nutritious meals for school-aged children and treatment of parasitic infections be included in the curriculum of school children