Asian Journal of Microbiology and Biotechnology
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Molecular Detection of Carbapenemase and Fluoroquinolone Resistance Genes in Pseudomonas aeruginosa Isolated from Hospital Waste
No full textHospital waste poses a significant environmental and public health threat due to its potential to harbour and spread antibiotic-resistant pathogens. Among these, Pseudomonas aeruginosa, a well-known opportunistic bacterium, is particularly concerning due to its multidrug resistance and ability to persist in hospital environments. This study aimed to determine the prevalence, antimicrobial resistance profiles, and molecular detection of carbapenem and fluoroquinolone resistance genes in P. aeruginosa isolated from hospital waste.
A total of 60 hospital waste samples were aseptically collected from the laboratory, outpatient and surgery units of Nnamdi Azikiwe Medical Centre. Isolation and identification were performed using cetrimide agar and standard microbiological methods. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer disk diffusion method in accordance with CLSI (2022) guidelines. PCR assays were conducted to detect the presence of carbapenemase (NDM, KPC) and fluoroquinolone (QnrA) resistance genes. Among the 60 samples analysed, 22 (36.7%) were confirmed as P. aeruginosa. High resistance rates were observed for levofloxacin (77.3%), ofloxacin (59.1%), ciprofloxacin (54.5%), imipenem (50%), and meropenem (40.9%). Six isolates (27.3%) were identified as multidrug-resistant. PCR analysis revealed the presence of the blaKPC, blaNDM, and QnrA genes among the isolates, indicating the presence of multiple resistance mechanisms. These findings demonstrated that hospital waste serves as a significant reservoir for multidrug-resistant P. aeruginosa, which carries clinically relevant resistance genes. Effective treatment of hospital waste, strict enforcement of infection control practices, and the implementation of antibiotic stewardship programs are essential to mitigate the environmental spread of antimicrobial resistance
Antibiotic Susceptibility Pattern of Bacteria Isolated from Elechi Creek in Rivers State, Nigeria
No full textAntibiotic Susceptibility Pattern refers to the ability of microorganisms to grow in the presence of an antimicrobial agent at a concentration that will normally kill or inhibit their growth. Antimicrobial resistance has become a major global threat, making treatment of infections tougher, especially with the high cost of treatment in humans and animals. This study was done to determine the Antibiotic Sensitivity Pattern and Multiple Antibiotic resistance index (MARI) of bacteria isolated from Elechi Creek. Two hundred and ten (210) samples were collected from five (5) points along the creek for a period of six (6) months. Bacterial Isolates were identified by standard microbiological methods. The isolates identified were Bacillus sp., Staphylococcus sp., Enterococcus sp., Pseudomonas sp., Vibrio sp., Proteus sp., Salmonella sp., Shigella sp., Escherichia coli, Enterobacter, Klebsiella sp. and Providencia sp. Antibiotic susceptibility testing was carried out using the disc diffusion technique. The organisms were tested against Cefuroxime, Gentamicin, Ceftriaxone, Erythromycin, Cloxacillin, Ofloxacin, and Augmentin for gram-positive Isolates. Cefuroxime, Gentamicin, Cefixime, Ofloxacin, Augmentin, Nitrofurantoin, Ciprofloxacin for gram-negative isolates. The isolates obtained showed 100% resistance to ceftazidine, cefuroxime, augmentin and cefixine. The MARI values ranged from 0.4 to 0.8 amongst the isolates. These results suggest that bacterial organisms isolated from Elechi Creek can contribute significantly to the spread of multi-antibiotic-resistant organisms. This could arise from indiscriminate use, causing an increased number of antibiotic-resistant strains in organisms. The study recommends close monitoring of antibiotic resistance in our environment and controlled use of antibiotics within the creek environment since the water serves as a source of domestic activity
Performance and Microbial Internalization by Tomatoes Grown on Composted Municipal Solid Wastes
No full textFor this study, the waste was sorted and composted in 20 L buckets A and B in replicates. A was amended with cow dung collected from Odo-Eran Abattoir in Abeokuta, while B was not. The temperature, pH, microbial succession, heavy metal concentration, and chemical properties of the composts were monitored at weekly intervals for 95 days using standard methods. Planting of test crop was done in a complete randomized block design, while the growth performance were determined by comparing the leaf length, leaf numbers, plant height, and numbers of fruits. Internalization of bacterial and fungal species by the test crops was also determined. Isolates were identified using 16sRNA gene amplification and sequencing for bacteria, and 16sF sequencing for yeasts and molds respectively. Antibiotic susceptibility of the isolates was determined by disc diffusion method. Temperature of the compost ranged between 22˚C-43˚C, the pH increased over time till termination of the experiment. Microbial counts during composting ranged from 0.8-2.0 CFU/mL in treatment A and B. Amendment of soil with composts improved the growth of crops (leaf length, leaf and fruit numbers, fruit size, and plant height in tomatoes), and also the proximate properties. For example, the organic matter (mg/kg) in CMSW was 20.37 %, while MSW had 13.64 %; average fruit numbers was 13.0 for CMSW, and 8.0 for MSW. Bacteria isolated include; Lysinibacillus fusiformis, Enterobacter cloacae, Pseudomonas aureginosa, Lysinibacillus sphaericus, Bacteroides vulgatus, Bacillus cereus, Escherichia coli, Providencia alcalificiens, Bacillus anthracis (Sterne), Providencia rettgeri, and Enterobacter asburiae. Molds include; Aspergillus niger, Rhizopus sp., Penicillium notatum; while yeasts include; Saccharomyces sp., and Candida sp. This study remarkably showed that direct use of MSW is not safe, hence, composting and amendment of composted wastes helps improve quality of the wastes for Agricultural uses, as well as yield and also reduced the uptake of microorganisms by test crop (Tomato)
Molecular Characterization of Hydrocarbon-Degrading Bacteria in Oil-Contaminated Soils from Mechanic Workshops in Abakaliki Metropolis, Southeastern Nigeria
No full textEngine oil is a hazardous pollutant that contaminates soil, water, and ecosystems. This study isolated and characterized hydrocarbon-degrading bacteria from engine oil-contaminated soils in three (3) mechanic workshops in Abakaliki, Ebonyi State, Nigeria. The bacterial populations were enumerated, and their degradation capacity was assessed using 2,6-dichlorophenol indophenol (DCPIP). Sample S2b had the lowest bacterial count (2.04 × 105 CFU/g; 0.89% of total isolates), while sample S2a had the largest bacterial population (1.01 × 107 CFU/g; 44% of total isolates). The bacterial counts obtained from the soil samples reflect the abundance of hydrocarbon-degrading microorganisms naturally present in the oil-contaminated environment. The isolates, including Pseudomonas putida, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Proteus mirabilis, demonstrated hydrocarbon degradation potential and were identified based on their Gram reactions and molecular characteristics using 16S rRNA. The results suggest that these native bacterial isolates can be used for bioremediation of oil-contaminated environments, providing a promising approach for pollution control and soil restoration in the region
Effect of Botanicals and Chemicals on Growth, Yield and Seed Quality of Mustard (Brassica juncea)
No full textA field experiment was carried out during the Rabi season of 2018–2019 at the Research Farm, Department of Genetics and Plant Breeding, Sam Higginbottom Institute of Agriculture, Technology and Sciences (SHIATS), Prayagraj, to evaluate the effect of different concentrations of botanicals and chemicals on growth, yield and seed quality of mustard. The experiment was laid out in a Randomized Block Design with three replications and eleven treatments. The treatments consisted of garlic, ginger and neem extracts at 10%, 15% and 20% concentrations, along with carbendazim, thiram and a control. The control (T0) recorded the lowest values for most traits, with 79.15% field emergence, 39 days to flowering, 125.43 cm plant height, 38.73 siliquae per plant, 7.40 seeds per siliqua and only 0.74 g seed yield per plant. Among the botanicals, garlic extract at 10% concentration (T7) performed best, producing the highest field emergence (92.55%), earliest flowering (33.67 days), 136.20 cm plant height, 40.80 siliquae per plant, 10.27 seeds per siliqua and the highest seed yield (1.85 g per plant), along with the maximum economic yield (48.41 g) and harvest index (31.63%). For seed quality parameters, garlic extract at 15% concentration (T8) recorded superior performance, enhancing germination percentage, root length, seedling length and vigour index compared to the rest. Although ginger and neem extracts at 10–20% concentrations produced comparatively lower yield values—such as neem 10% (T4) showing 74.07% field emergence and 1.40 g seed yield per plant—they remain eco-friendly, safe and low-cost alternatives to chemical seed treatments. Overall, the study concludes that garlic extract at 10% concentration is most effective for improving mustard growth and yield, while 15% garlic extractis superior for enhancing seed quality. These findings indicate that farmers can adopt garlic extract seed treatments at appropriate concentrations as an affordable and eco-friendly method to improve mustard productivity and seed quality under field conditions
Rumen Manipulation Strategies towards Enhancing Feed Efficiency and Reducing Methane Emissions in Ruminants Fed Low Quality Feeds: A Review
No full textRumen manipulation is a specialized technique employed to modify or optimize the rumen environment and its microbial ecosystem to enhance the efficiency of feed utilization, thereby improving animal productivity and reducing the production of undesirable byproducts, such as methane. This methane loss is 5-12% of gross energy intake of animal and contribute to the global warming. India\u27s 20th livestock census documented that India has the world\u27s largest livestock population. Maintaining such a large number of livestock using green fodder and hay is not possible because less than 5 percent of the total cultivated land is used for fodder production. Therefore, livestock feeds in India primarily comprises cereal crop residues, low-quality roughages (tropical forages), and lignocellulosic agro-industrial byproducts, due to their abundance and low cost. However, these materials exhibit low digestibility, lower energy value and also contain toxicants resulting in a significant portion of the feed remaining undigested. These factors are significant contributors to the low productivity of dairy animals. Therefore, manipulating ruminal fermentation is very crucial. This article explores various genetic and non-genetic approaches to optimize rumen function. Genetic interventions, such as genetic engineering of naturally occurring rumen bacteria and the introduction of novel microbial species or strains, offer promising avenues for enhancing cellulose degradation, neutralizing toxins, and mitigating ruminal acidosis. However, challenges such as low microbial viability, substantial expertise requirements, limited efficacy rates, and ethical concerns about potential risks to animal and human consumers hinder their widespread adoption. Non-genetic approaches include Use of Ionophore compounds, Organic acids, Defaunation agents, and Probiotcs. These approaches provide practical solutions to tackle the nutritional challenges associated with tropical forages and low-quality feeds. These methodologies enhance feed efficiency, reduce methane emissions, and improve overall animal productivity
Comparative Antimicrobial Activity of Lagenaria breviflora Whole Fruit and Curculigo pilosa Rhizome against Some Clinically Significant Pathogens
No full textMedicinal plants have historically been a rich source of bioactive compounds with therapeutic potential and antimicrobial properties. In this research, 2kg each of Lagenaria breviflora and Curculigo pilosa were obtained from Bode market, Ibadan and authenticated at the herbarium section of the Forestry Research Institute of Nigeria (FRIN), Ibadan. Typed strains of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans were obtained from the Microbiology section, University College Hospital, Ibadan. Crude extract of the plants was carried out using ethanol extraction for 72 hours followed by a qualitative analysis of the Phytochemicals in the extracts. In-vitro antimicrobial assays based on the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the raw, 100 mg/mL, 50 mg/mL, 25 mg/mL, and 12.5 mg/mL extracts were also carried out following standard microbiological methods. Descriptive statistics and ANOVA at α0.05 was used to analyze the data. The phytochemical composition of both plants showed that they contained tannins, saponins, and terpenoid while flavonoids were only present in L. breviflora. At 100 mg/mL of the plant extracts, there was an overall high level of inhibition in the growth of the Staphylococcus aureus with an average inhibitory zone diameter of 11.5±1.5 mm and 16.5±0.7 mm in L. breviflora and C. pilosa respectively while at a concentration of 12.55 mg/mL there was no growth inhibition of the test pathogens. In L. breviflora, the MIC was observed for 100 mg/mL in Staphylococcus aureus and Candida albicans with an average zone inhibition of 0.987±0.02 mm and 0.956±0.03 mm, respectively while for C. pilosa, the MIC was observed in the raw extract for Candida albicans with an average inhibition zone of 0.997±0.02 mm. This study revealed that L. breviflora and C. pilosa extracts show potential antimicrobial activity against clinical pathogens, including Gram-positive and Gram-negative bacteria and yeast
Biosolubilization of Plant Essential Minerals in Soil: Current Findings and Future Prospects
No full textBy 2050, the global population is expected to reach 9 billion, increasing food demand by 70%. Fertilizers, especially nitrogen, potassium, and phosphorus (NPK), are essential for agricultural productivity. Phosphorus is vital for plant growth, but its availability in soil is often limited, reducing crop yields by up to 15%. Soil microorganisms, through biosolubilization, play a crucial role in converting minerals into plant-absorbable forms thus improving soil fertility and supporting sustainable farming practices. Microorganisms, like Azospirillum brasilense and Bacillus megaterium are known for solubilizing phosphorus and potassium, produce organic acids and enzymes that break down minerals, offering an eco-friendly alternative to chemical fertilizers. Microbial consortia, combining bacteria and fungi, enhance solubilization efficiency through cooperative interactions. Biosolubilization also aids in soil remediation and waste treatment. The implications of this review are ecological alternatives to chemical fertilizers, reducing the environmental footprint of chemical hazards, understanding microbial interactions and optimizing practices based on local conditions which can address challenges like nutrient deficiencies and the high cost of fertilizers, ensuring food security and promoting sustainable farming. The genetic regulation of microbial solubilization helps develop efficient biofertilizers, reducing dependency on chemical fertilizers. Microbial biosolubilization is essential for sustainable agriculture, enhancing soil health and plant growth. Therefore, continuous research in this area is essential to maximize its full potentials and for environmental stability
Genetic Diversity of Rice Bacterial Leaf Blight Pathogen, Xanthomonas oryzae pv. oryzae in Godavari Zone of Andhra Pradesh, India
No full textBacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the major biotic constraints limiting yields in paddy in Andhra Pradesh. The present study was conducted at ANGRAU – Regional Agricultural Research Station, Maruteru, Andhra Pradesh, during Kharif 2024 to understand genetic variability among twenty Xoo isolates collected from five districts of the Godavari zone in Andhra Pradesh. Bacterial genomic DNA was extracted, analysed for purity and concentration, followed by PCR amplification using universal 16S rDNA and Xoo-specific JEL marker primers. Most virulent BLB isolate (Xoo7) in the present study was characterised as the Xanthomonas oryzae pv. oryzae by using universal primer 16S rDNA sequence. Genetic diversity assessed using JEL primers (targeting IS1112 sequence) and UPGMA clustering analysis revealed considerable genetic variability among the twenty Xoo isolates; the isolates were grouped in two major clades in the dendrogram. The clustering pattern corresponded with geographical origin and rice cultivars, suggesting localized adaptation. These findings offer valuable insights into the pathogen’s population structure and have implications for disease management strategies and breeding programs
Prevalence, Molecular Detection and Antimicrobial Resistance Patterns of Some Bacteria Causing Bovine Mastitis
No full textAntimicrobial resistance (AMR) is a global health concern affecting both human and veterinary sectors. Overuse and misuse of antibiotics is accelerating the problem of antimicrobial resistance in the pathogens causing infectious diseases. Mastitis is the painful inflammation of mammary gland and is considered as common infection of dairy cattle. Several studies emphasized that the bacterial pathogens associated with bovine mastitis are multidrug resistant. Hence, the present study is carried out to determine prevalence and antimicrobial resistance patterns of bacterial pathogens causing bovine mastitis. A total of 120 mastitic milk samples were collected and the prevalence rates were analyzed according to breed, age, parity and lactation stages. The identification of bacterial strains was performed based on cultural characteristics on specific media, biochemical tests and molecular identification using specific primers. Antibiotic susceptibility testing of the isolates was done by Kirby-Bauer disk diffusion test. Results indicated the presence of Staphylococcus aureus, Escherichia coli, Klebsiella, and Salmonella spp. at prevalence rates of 19.53%, 10%, 2.5%, and 5.8% respectively. Determination of the AMR profile revealed the resistance of all pathogens towards ampicillin. S. aureus is predominantly resistant to penicillin (100%), followed by methicillin (94.74%), and ampicillin (89.47%), E. coli to ampicillin (96.6%), amoxicillin and ciprofloxacin (83.33% each), Klebsiella to ampicillin and amoxicillin (100%) whereas Salmonella spp. to ampicillin (100%) and amoxicillin (85.71%). The findings of the study suggested the high prevalence of multidrug resistant pathogens causing mastitis, increasing the risk of reduced antimicrobial efficacy and affecting the public health