Open Access Original Research Article

Prevalence of Pseudomonas aeruginosa’s Virulence Genes Isolated from Human Infection in Abidjan, Côte d’Ivoire

Clarisse Kouamé Elogne, AKA N’Guetta, Alain Yeo, Coulibaly N’golo David, Nathalie Guessennd, Jean Claude Anné, Tatianah Kangah Ngoran, Sofia Okpo Boyou, Adèle Kacou N’douba, Hortense Ketté, Mireille Dosso

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/MRJI/2018/44475

The aim of this study was to evaluate the distribution of virulence genes among clinical isolates of P. aeruginosa and to compare these factors with the localisation of clinical infection and the serotypes.

151 isolates of P. aeruginosa were collected from various biological fluids: The strains were identified based on the standard bacteriological characteristics. The serotyping of the strains was done. The Detection of virulence genes was done by polymerase chain reaction (PCR).  The genes sought were: PilB, lasB, nan1, algD, plcH, exoS, and exoU genes.

The most common virulence factor found in clinical strains of P. aeruginosa was, alg D (encoding for alginate) with a prevalence of 90.7%, plch (haemolytic phospholipase C precusor) with 84.1%, las B (elastase B) 72.8%, pilB (type IV fimbrial biogenesis protein pilB) 70.2%, nan1 (neuraminidase) 37.1%, exoS (exotoxin S) 31.1% and exoU (exotoxin U) 17.9 %. Infections with the highest virulence levels were sepsis and lung infections. The exoS gene was more frequently found in serotypes O2 (43%), O4 (39%) and O3 (25%). As for the exoU gene, the prevalent serotypes were O11 (28.8%) and O1 (20%). The multidrug resistant P. aeruginosa isolates were most frequently associated with the presence of algD (78.6%), plch (71.4%), lasB (64.3%), pilB (42%), and nan 1 (42%).

P. aeruginosa of invasive infections like septis and lung infections had the highest level of virulence.

Open Access Original Research Article

The Bacteriological Index of Bioslurry and the Fate of Pathogenic Bacterial Organisms during Anaerobic Digestion of Domestic Waste in a Biogas Plant

F. C. Akubuenyi, S. A. Achor

Microbiology Research Journal International, Page 1-9
DOI: 10.9734/MRJI/2018/44346

The bacteriological index of bioslurry and the fate of pathogenic bacteria during anaerobic digestion of domestic waste were determined. The wastes (food waste, vegetable waste, plantain peels, yam peels, and cow dung) were collected from households and markets within the Cross River University of Technology, Clalabar, Nigeria, and the analysis conducted at the Microbiology Department of the University. Bacteriological index was examined by enumerating the total heterotrophic bacterial (THB) count and bacterial diversity during the digestion period using viable count method on nutrient agar plate. The fate of pathogenic bacteria was analysed at 2 week interval for a period of 28 days using Salmonella and Shigella species as a case study. Results showed that the THB count decreased (1.8x1010CFU/ml – 6.3x108CFU/ml) over the 28 day period of anaerobic digestion. The isolation and identification of different bacterial species associated with anaerobic digestion of waste revealed the presence of aerobic, facultative anaerobic and anaerobic bacteria in Days 1, 14 and 28 respectively. Pseudomonas spp, Bacillus spp, Lactobacillus spp, Klebsiella spp, Proteus spp, Escherichia coli and Staphylococcus spp were among the organisms isolated on Day 1, which indicates that the initial microbial hydrolytic activities on the waste materials are mediated by aerobic and facultative anaerobic bacteria. The presence of Staphylococcus spp, Enterococcus spp, Peptostreptococcus spp, Micrococcus spp and Fusobacterium spp were present in the sample analysed on Day 14 showing that the digester was becoming anaerobic. Isolation of Propionibacterium spp, Listeria spp, Erysipelothrix spp and Clostridium spp on Day 28 showed that the digester has turned anaerobic, the stage at which biogas is produced. The result of the fate of pathogenic bacteria revealed that Salmonella and Shigella species decreased with time during the digestion process, with complete die off at Day 21. These indicate that anaerobic digestion enhances pathogen die off and could be applied as a waste treatment option in an integrated waste treatment management. A study on the metagenomics of the bioslurry will further reveal the uncultured and genomic diversity of associated microorganisms during anaerobic digestion.

Open Access Original Research Article

Phenotypic and Genotypic Characterisation of Bacteria Associated with Acacia gummifera Wild

Fatima Zahra Lahdachi, Laila Nassiri, Jamal Ibijbijen

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/MRJI/2018/43531

Aims: The study aimed to isolate and analyse the phenotypic and genotypic features of bacteria nodulating Acacia gummifera Wild.

Study Design:  An experimental study.

Place and Duration of Study: The study was done at the Department of Biology (Soil & Environment Microbiology Unit), University of Sciences Meknes, Moulay Ismail University and National Center of Research Science and Technical Division Rabat-Morocco, during April 2015 to May 2016.

Methodology: Samples were collected from 15 sites of Skhour Rhamna region, Morocco, to isolate bacteria that can be able to nodulate Acacia gummifera. Phenotypic parameters as growth speed, mobility, tolerances to temperature, salt, and pH were studied. To evaluate the genotypic characteristics, a molecular characterisation based on the 16S rRNA gene was performed.

Results: The majority of the isolate is fast growing. All isolate tolerated high temperatures (40°C), and a NaCl concentration that exceeds 800 mM and the majority of them increased under pH ranging from 7 to 10. Furthermore, the molecular characterisation showed the bacterial diversity belonging to the genera Ensifer, Rhizobium and Acinetobacter.

Conclusion: The Moroccan gum tree recruits a diversified strain that can be developed as a new bio-fertiliser.

Open Access Original Research Article

Production, Characterization and Optimal Performance Studies of Glucose Isomerase by Achromobacter xylosoxidans mck-4 Isolated from Starch Milling Wastes

M. C. Mbagwu, E. J. Egong, O. D. Akan

Microbiology Research Journal International, Page 1-17
DOI: 10.9734/MRJI/2018/43139

Seventy-five (75) bacterial isolates from starch milling wastes in Nsukka, Nigeria were screened for their ability to produce glucose isomerase (GI). The isolate Achromobacter xylosoxidans Mck-4 gave the highest activity of intracellular GI using starch casein agar (SCA) medium supplemented with nystatin to eliminate fungi contaminations, incubated at 30°C for 48 hours and pH 7. The SDS PAGE showed that the enzyme was partially purified and the band was near the protein marker of 43 KDa. The enzyme was purified 4.7 fold with a specific activity of 6.4±0.52 U/mg of protein and 30.9% enzyme recovery in the final desalted sample. The Km value calculated for glucose by Lineweaver Burk plot is 0.89 moles and Vmax was 6.4±0.52 U/mg. The highest activity of the enzyme was at a temperature of 70˚C and pH 7 and maximally activated by the cations; magnesium and cobalt with magnesium having the highest effect followed by manganese and cobalt in individual effects. These parameters for the production of GI by Achromobacter xylosoxidans mck-4 are well in the range of economic feasibility; therefore such a process has good chances for industrialization. It is recommended that the gene from our isolate should be isolated and cloned in GRAS status organism to scale up enzyme production and optimize industrial production of high fructose corn syrup (HFCS) in Nigeria using agro-residues.

Open Access Original Research Article

Salmonella Serovars Isolated from Brown Rats (Rattus norvegicus) from Grenada, West Indies: Prevalence and Antimicrobial Susceptibility

Ravindra Sharma, Keshaw Tiwari, Gitanjali Arya, Victor Amadi, Darnell Blackman, Nicholas Markette, Tomer Shua-Haim, Roxanne Nicholas-Thomas, Harry Hariharan

Microbiology Research Journal International, Page 1-8
DOI: 10.9734/MRJI/2018/44563

Aim: The purpose of this study was to estimate the prevalence of Salmonella species and to determine the antimicrobial susceptibility of isolates in brown rats (R. norvegicus) from two parishes (St. George and St David) of Grenada, West Indies.

Study Design: Salmonella spp.  was investigated in brown rats from Grenada, West Indies.

Place and Duration of Study: Rats were trapped from two parishes: St David and St. George of Grenada, West Indies. Duration of study was from May to July 2017.

Methodology: One hundred and seventy rats were trapped from 2 parishes (St. George and St David) of Grenada which have dense human population. The trapping was performed near the human dwellings. After necropsy, intestinal contents were collected and cultured for Salmonella bacteria using enrichment and selective culture techniques. Serotyping of Salmonella isolates was performed at the OIE Salmonella reference laboratory Guelph, Ontario, Canada. Antimicrobial susceptibility of the serovars was tested.

Results: Fifteen rats (8.8%) were found positive for Salmonella spp. Five serovars of Salmonella were identified: S. javiana (36.8%); S. panama (26.3%); S. oranienburg and S. montevideo (15.7%) each; and L: Rough (5.2%). S. oranienburg has been isolated for the first time in Grenada. All serovars were found susceptible to 10 antimicrobial drugs; amoxycillin clavulanic acid, ampicillin, Choramphenicol, cephalothin, ciprofloxacin, ceftazidime, acefotaxime, imipenem, gentamycin and neomycin. Resistance of serovars to two antimicrobial drugs (tetracyclin and sulfamethoxazole-trimethaprim) was observed. 

Conclusion: All serovars identified in brown rats in Grenada are known pathogens causing serious disease in humans. Presence of Salmonella spp. in rats in a densely human populated area of Grenada may play a role in transmission of Salmonella to humans.