Antibiotic resistance profile and phenotypic detection of beta-lactamase-producers among gram-negative bacteria isolated from the gut of household cockroaches in and around University Of Ibadan

Background: Cockroaches are carriers of numerous microorganisms. However, there is paucity of information on their role as potential reservoir for beta-lactamase  producers.Objectives: This research determined the antibiotics susceptibility profile of Beta-lactamase producing Gram-negative bacteria isolated from the gut of  household cockroaches in selected locations in and around University of Ibadan, Oyo state.Materials and Methods: Thirty Cockroaches from different locations in and around University of Ibadan were collected between June 2015 and March, 2016, and their intestinal homogenates cultured on different selective media for the isolation of  bacteria. The isolates were identified using a combination of biochemical tests and 16S rRNA sequencing. Antibiotic susceptibility testing was done using the  disc-diffusion technique and phenotypic detection of extended-spectrum  beta-lactamase (ESBL), AmpC-beta-lactamase (AmpC) and Metallo- beta-lactamase (MBL) production was done using double-disc synergy,  cefoxitin/cloxacillin and imipenem/EDTA double-disc methods respectively.Results: A total number of 58 bacteria belonging to nine genera; Pseudomonas, Proteus, Klebsiella, Salmonella, Enterobacter, Escherichia, Serratia, Shigella and Raoultella were isolated. Higher percentage of the isolates exhibited resistance to  erythromycin (90%), azithromycin (87.5%), amoxicillin (84.5%), ampicillin  (74.1%), amoxicillin-clavulanic acid (74.1%), cefoxitin (67.2%) and  chloramphenicol (54%), while lower percentage showed resistance to aztreonam (25%), ertapenem (13%), cefotaxime (8.6%), ceftazidime (10.3%), cefepime (5.2%), ciprofloxacin (3.5%), gentamicin (5.2%) and imipenem (0%). MDR  phenotype was recorded among 82% of the isolates, 17.2% were positive for ESBL, 12% for AmpC and 13.8% for MBL production.Conclusion: This study identified household cockroaches Periplaneta americana, as a potential reservoir for MDR and beta-lactamase-producing isolates.Keywords: Susceptibility testing, ESBL, AmpC, MBL, Beta-Lactamase, MDR, Household cockroache

Assessment of microbial quality and detection of extended spectrum β-lactamase genes in Gram-negative bacterial isolates of herbal mixtures commonly hawked in Sagamu metropolis, Ogun State, Nigeria

Background: The use of herbal mixtures in the treatment of diseases is on the rise. Many of these herbal drugs are not produced under hygienic conditions and safety issues associated with herbal medicines may have an exacerbated impact in immunocompromised and elderly individuals. This study aimed to determine the microbial loads of locally prepared herbal mixtures and detect extended spectrum beta-lactamase (ESBL) genes  in any isolated Gram-negative bacteria pathogen. Methodology: Fifty local herbal mixtures were purchased randomly from three locations in Sagamu town (Sagamu market, Ita-Oba Road and Isale  Oko) in Ogun State, Nigeria. The mean total viable bacterial (MTVB), mean total coliform (MTC), and mean total fungal (MTF) counts were  determined by the plate count method. The bacterial isolates were streaked on differential bacteriological media while the fungi isolates were  grown on potato dextrose agar. The isolates were identified upon growth on culture media using conventional biochemical tests. Antibiotic  susceptibility pattern of the isolates was determined using Kirby-Bauer disk diffusion technique. Phenotypic detection of ESBL was done by the  modified double disc synergy test followed by amplification detection of blaTEM, blaCTX-M and blaSHV genes with polymerase chain reaction (PCR)  assay. Results: Bacteria and fungi were isolated from 38 (76.0%) and 25 (50.0%) of the herbal samples respectively. Ten (20.0%) and 14 (28.0%) of the  samples had mean bacterial and fungal load that exceeded 105CFU/mL or g, respectively. Nineteen (38.0%) of the herbal samples analyzed had total  coliforms. Fifty-one isolates belonging to eight bacterial genera and 28 fungi isolates belonging to four fungal genera were obtained. Thirty-  two (62.7%) of the bacterial isolates were Gram-negative while 19 (37.3%) isolates were Gram-positive. Staphylococcus aureus was the most  common bacterial isolate (33.3%) while Aspergillus species was the most prevalent fungus (60.7%). Sixteen (84.2%) S. aureus and 26 (81.3%) Gram- negative isolates were multidrug resistant, and 6 (18.8%) of 32 Gram-negative isolates were ESBL producers. ESBL-encoding genes were detected in  7 (27%) of the 26 multidrug resistant Gram-negative bacteria with TEM and SHV being the most prevalent 4 (14.8%) while CTX-M was identified in  only one isolate. Conclusion: This study reported the presence of microbial contaminants which exceeded the safety limits of 105 CFU/g according  to World Health Organization. The use of locally prepared herbal medicines poses a major health risk due to the lack of microbial quality standards.&nbsp

The effect of a fixed non-mineral oil on the antibacterial activity of ampicillin trihydrate against resistant clinical strains of Staphylococcus aureus

The effect of King's Vegetable oil, a fixed non-mineral oil, on the antibacterial activity of ampicillin trihydrate, a water- insoluble form of ampicillin, was investigated against resistant clinical strains of Staphylococcus aureus. In the agar-diffusion method employed, 40% of the resistant clinical strains tested showed sensitivity to different oil-dispersed concentrations of ampicillin trihydrate, which ranged from 0.06µg/ml to 1.25µg/ml. The resistant strains were among the clinical strains detected with Beta-lactamase. This finding is presented as a preliminary report on the potentiality of employing an oil medium to effect a "cure" of antibiotic resistance in staphylococci besides the use of acridine dyes, ethidium bromide, ultraviolet radiation and other measures

PERFORMANCE OF AN ACID-CASSAVA STARCH MEDIUM IN THE PROPAGATION OF FUNGI.

Propagation of mould and yeast isolates was carried out on a formulated acid-cassava starch medium (A-CSM) and commercial potato dextrose agar (PDA). The two media were also used to enumerate some of the fungal isolates. Cultural and morphological characteristics expected of filamentous fungi and those with transitional forms were observed on both A-CSM and PDA. Growth was more rapid in respect of most of the fungi on A-CSM but it was accompanied with minimal liquefaction, after 48 hrs of incubation. Similarly, the A-CSM produced greater viable counts of most of the fungi. The acid-cassava starch medium reported is considered a potential alternative to its equivalent commercial nutrient media such as PDA

Serum Protein Binding and the Antimicrobial Activities of Garcinia Kola, Kola Acuminata and Kola Nitida Seed Extracts on the Agents of Respiratory Tract Infections

The kinetics of bactericidal activity of the methanolic extracts of powdered seeds of Garcinia kola (Heckel), Kola acuminata and Kola nitida obtained by soxhlet extraction, were studied using two bacterial sensitive strains of Staphylococcus aureus and Pseudomonas aeruginosa. The study showed that the three extracts at the concentrations used against the two test organisms, Staphylococcus aureus OOUTH206 (0.5mg/ml for Garcinia kola, 4mg/ml for Kola acuminata and Kola nitida) and Pseudomonas aeruginosa UCH189 (8mg/ml for Garcinia kola, 15mg/ml for Kola acuminata and Kola nitida); had activity on the two microorganisms. There was a gradual reduction in the number of viable microbial counts as evident in the reduction in the cell number at the different time intervals. Similar procedure was carried out in the presence of 5% serum protein and it was observed that the activities of the various extracts were altered significantly indicating the effect of serum protein binding on the constituents of Garcinia kola, Kola acuminata and Kola nitida seed extracts. The results were expressed in percentage viable count of the inoculum size and showed that the percentage viable count decreases with time in varying degrees. The reduction was more intense with G. kola extract than the other extracts on S. aureus as well as on P. aeruginosa towards the third and fourth hours. The effect of serum protein was seen to affect the activities of all the extracts in varying degrees as shown in the graphs plotted.Key words:  Garcinia kola, Kola acuminata, Kola nitida, methanolic extracts, respiratory tract infections, serum proteins.

Microbiological quality of local soymilk: A public health appraisal

The ubiquity in the hawking of locally produced soymilk, packaged in different forms, was considered a public health concern. The attendant increase in the rate of soymilk consumption has encouraged low scale production of the milk under household condition with little or no regard to quality control measures. Accordingly, branded and unbranded soymilk samples were subjected to microbiological analyses to ascertain their hygienic standard of production. The soymilk samples were found to have pH in the range of pH 7.2 to 7.5. Screening for microbial contaminants revealed generally high bacterial and fungal counts of 2.9 x 107 cells/ml. to 1.02 x 108 cells/ml. and 3.5 x 107 to 2.13 x 108 cells/ml. respectively as well as high Most Probable Number (180+) of coliform bacilli per 100ml of each sample. Regular contamination with Escherichia coli , other faecal coliforms and Staphylococcus aureus was detected in all the samples. In addition, Pseudomonas aeruginosa , other Gram-negative bacilli and streptobacilli were detected in most of the nylon packed (unbranded) samples. The fungal isolates were mainly Aspergillus spp., Penicillium spp and Fusarium . The microbial population detected in terms of number and types reflected poor hygienic standard of production, constituting a public health hazard among the populace. There is a need to streamline soymilk production for proper monitoring and quality assurance