Characterization of Bacterial Strains from Rotten Fruits Treated with Harmful Preservatives

Background: Fruits are beneficial to maintain good health, but microbes can spoil them. To avoid spoilage of fruits different harmful preservatives are being used that pose danger to human health and environment. This study was designed to isolate bacterial strains from rotten fruits preserved by using different preservatives.Methods: Different rotten fruit samples were collected from different shops of Moon Market and Neelam block, Allama Iqbal Town, Lahore and used to purify bacterial cultures by growing on simple N-agar medium. Biochemical characterization was performed by different tests including gram staining, catalase, mannitol salt agar, glucose and fructose fermentation and nitrate reduction. Bacterial strains were further subjected to additional tests like HCN, H2S production, metal resistance and antibiotic sensitivity.Results: Nineteen bacterial strains were found positive for different tests and were characterized as Bacillus sp, Staphylococcus aureus, Micrococcus varians, Staphylococcus epidermidis and Staphylococcus saprophyticus. Many bacterial strains were resistant to antibiotics and high doses of most metals specially mercury. Conclusion: Due to the use of high doses of mercury for the storage of fruits, microorganisms have evolved resistance. It is an urgent need to take alternative measures for the storage of fruits for the safe lives.Keywords: Metal resistance; Antibiotic resistance; Fruit preservation; Staphylococcus sp.

Characterization of mercury resistant and growth promoting Enterobacter sp. from rhizosphere to use as a biofertilizer

Background: Mercury occurs naturally in environment, it is heavy metal that exists in three chemical forms like elemental mercury, inorganic mercury and organic mercury. All forms of mercury are problematic for living organism. Currently, the contamination of agricultural land and water systems with mercury has become one of the major environmental issues. The cheapest mode to remove mercury metal and its other forms from the ecosystem is the use of microorganisms.Methods: In this study, initially bacterial species were isolated and purified from nodule like structures on roots and stems of plants on MacConkey agar medium. Further screening for resistance to mercury was done on N- agar medium supplemented with different concentration of HgCl2 (20, 30, 40 and 50 µg/mL). Well plate method was used for the determination of bacterial strains having maximum ability to detoxify mercury. Selected bacterial strains were subjected to different biochemical tests for characterization and other metabolic tests were also performed to characterize their capabilities.Results: All strains were highly resistant to HgCl2 at the concentration of 20 µg/mL and moderately resistant at 30 µg/mL. Bacterial strain S-2 was moderately resistant and S-3 was least resistant at 40 µg/ml whereas S-2 was least resistant at 50 µg/ml. Selected bacterial strains were positive for nitrogen fixation and protease production, negative for phosphate solubilization but only S-1 was positive for hydrogen cyanide (HCN). Bacterial species were molecular characterized by 16S rDNA sequencing as Enterobacter cloacae (KJ857483, KJ857484 and KJ857485: NCBI GeneBank).Conclusion: Selected Enterobacter sp. exhibiting multiple characteristics can be used as biofertilizer in mercury polluted land for sustainable agriculture

Phytotoxicity of Hg and its Detoxification through Microorganisms in Soil

Due to the advent of industrialization, pollution of terrestrial environment by heavy metals has emerged as a great issue. Therefore, it is an urgent need to realize the Hg-induced toxicity in plants and as well as in animals and the harmful effects by the consumption of contaminated nutrition. Mercury is considered as a hazardous contaminant that can be changed into various oxidation states easily and causes many deleterious effects in several physiological processes in both plants and animals. Microorganisms possess two extensively studied Hg-detoxification processes like Mer operon (merTPCFAD) and Met gene which encode the functional proteins for transportation (merT, merP and/or merC, merF), reduction (merA) and a secondary regulatory protein (merD) and sulfhydrylase enzymes (met gene) respectively to modify toxic Hg+2 to nontoxic elemental state (Hg0). Due to the ever increase in Hg-pollution and very little information about its phytotoxic effects and detoxification mechanisms, the authors expect, the present article will make possibility in the provision of  a comprehensive literature study about Hg-induced toxicity in plants and its detoxification processes to provoke for advance research in this field

Screening of natural extracts for their antibacterial activity against different enteric pathogens isolated from soil, water and rotten fruit samples

Different bacterial strains were isolated from soil, water and rotten fruit samples, and biochemically characterized as Shigella, Pseudomonas, Escherichia coli, Klebsiella and Proteus. Unhygienic environment (for example, contaminated food, water and air) are the most common habitats of these pathogens. Mostly, all are involved in endemic breakouts causing urinary tract and gastro-intestinal infections. The antibacterial activity of four concentrations of natural crude extracts of medicinal plants namely Allium sativum (garlic), Nigella sativa (black cumin), Trigonella foenum-graecum (fenugreek), Ficus carica (fig), Azadirachta indica (Indian lilac) and honey was determined against a total of ten isolated organisms by well plate method. Test organisms were found to be more sensitive to aqueous extract of bulb of A. sativum, seeds of Nigella sativa and honey. The antibacterial activity of crude extract was comparable with ciprofloxacin and ceftriaxone, commonly used antibiotics for the treatment of infections in adults and children, respectively. It was observed from the studies that most of the test strains were resistant to the antibiotics used especially against ceftriaxone. Due to the emergence of drug resistant microorganisms, it is a need to search out more effective antimicrobial agents to cure the disease. Our studies suggest that aqueous crude extract of medicinally important plants and honey could be the alternative of the antibiotic to cure the diseases.Keywords: Ceftriaxone, Ciprofloxacin, Nigella sativa, Shigella, Proteu

Molecular typing of Methicillin Resistance Staphylococcus aureus(MRSA) isolated from device related infections by SCCmec and PCR-RFLP of coagulase gene

Background: SCCmec and PCR-RFLP are productive and cost-effective methods for epidemiological investigations and source tracking of MRSA. Aim of this study was to investigate the epidemiology and molecular characterization of MRSA recovered from device related infection. Methods: A total of 626 MRSA were collected from prosthetic device related infections and subjected for presence of mec gene and SCCmec typing. SCCmec characterized MRSA were subjected for agr typing followed by RFLP genotyping and amplification of PVL gene. Following the Clinical & Laboratory Standards Institute (CLSI), antibiotic resistance pattern was determined. Results: Of 626 MRSA isolates, 488(78%) were characterized by SCCmec typing. Most common type was SCCmec IV (43%), followed by SCCmec II (25%) SCCmec III (22%) and only 10% was SCCmec V.  SCCmec characterized MRSA strains were 100% resistance to tobramycin and chloramphenicol, 96% resistance to ciprofloxacin and 93% resistance to azithromycin. The genePVL was only present in SCCmec IV. All agr typed MRSA strains were resistance to gentamicin, tobramycin and chloramphenicol. PVL was present in all strains of agr III, 80% of agrIV, 50% of agrII and absent in agrI. RFLP analysis resulted in 16 types of non-duplicate unique bands pattern which were equally distributed among prosthetic device related infection. Conclusion: PVL harboring SCCmec or agr typed MRSA strains are less resistance to antibiotics. RFLP is simple, productive and cost-effective method for molecular typing of MRSA. Correct use of antibiotics and molecular surveillance is indispensable to detect the change in epidemiological and antibiotic resistance trends of MRSA

Viability assessment of in vitro produced synthetic seeds of cucumber

Friable, embryogenic calli of F1 cucumber (Cucumis sativus) cultivar, Royal, were induced from the hypocotyl pieces cultured on solidified MS-basal media supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) and benzyl amino purine (BAP). Embryogenic calli were transferred to liquid Murashige and Skoog (MS)-basal  media supplemented with 5 ƒÊM naphthaleneacetic acid (NAA) and 1 µM BAP. The mature somatic embryos  were encapsulated in sodium alginate mixture in synthetic seeds. The encapsulation mixture containing 3%  sodium alginate, 100 mM calcium chloride and one-fourth volume of the cell suspension nutrient mixture  containing 5x10-4 somatic embryos per ml was found the best. Synthetic seeds remain viable up to 14 weeks  when stored at 4°C. Germination efficiency of synthetic seeds was decreased to 57% after 10 weeks of  storage followed by rapid decrease in survival rate to 0% after 15 weeks. Genetic diversity between mother  plants and in vitro produced synthetic seeds showed resemblance as assessed by amplified fragment length polymorphism (AFLP) markers.Key words: Artificial seed, Cucumis sativus, encapsulation, somatic embryogenesis, sodium-calcium alginate

A Potential Biocontrol Agent Streptomycesviolaceusniger AC12AB for Managing Potato Common Scab

Potato common scab (PCS) is an economically important disease worldwide. In this study we demonstrated the possible role of Streptomyces violaceusniger AC12AB in controlling PCS. Isolates of Streptomyces scabies were obtained from CS infected tubers collected from Maine United States, which were confirmed by morphological and molecular analysis including 16S rRNA sequencing and RFLP analysis of amplified 16S-23S ITS. Pathogenicity assays related genes including txtAB, nec1, and tomA were also identified in all S. scabies strains through PCR reaction. An antagonistic bacterial strain was isolated from soil in Punjab and identified as S. violaceusniger AC12AB based on 16S rRNA sequencing analysis. Methanolic extract of S. violaceusniger AC12AB contained azalomycin RS-22A which was confirmed by 1H and 13C-NMR, 1H/1H-COSY, HMBC and HMQC techniques. S. violaceusniger AC12AB exhibited plant growth promotion attributes including Indole-3-acetic acid production with 17 μgmL-1 titers, siderophores production, nitrogen fixation and phosphates solubilization potential. When tubers were inoculated with S. violaceusniger AC12AB, significant (P < 0.05) PCS disease reduction up to 90% was observed in greenhouse and field trials, respectively. Likewise, S. violaceusniger AC12AB significantly (P < 0.05) increased potato crop up to 26.8% in field trial. Therefore, plant growth promoting S. violaceusniger AC12AB could provide a dual benefit by decreasing PCS disease severity and increasing potato yield as an effective and inexpensive alternative strategy to manage this disease

Molecular Characterization of Mercury Resistant Bacteria Isolated from Tannery Wastewater

Mercury resistant (HgR) bacteria were isolated from heavy metal polluted wastewater and soil, collected from the proximity of some tanneries from Kasur, Pakistan. Three out of 30 bacterial strains were screened out on the basis of resistance level against various concentrations of HgCl2. Bacterial isolates AZ-1, AZ-2 and AZ-3 showed resistance up to 40 μg/mL of HgCl2 and mercury sensitive (HgS) isolate ZA-15 was taken as a negative control. 16S rDNA ribotyping and phylogenetic analysis were performed for the characterization of isolates as Bacillus sp. AZ-1 (KT270477), B. cereus AZ-2 (KT270478), B. cereus AZ-3 (KT270479) and Enterobacter cloacae ZA-15 (KJ728671). Phylogenetic relationship on the basis of merA nucleotide sequence confirmed 51-100% homology with the corresponding region of the merA gene of already reported mercury resistant Gram-positive bacteria. Restriction fragment length polymorphism (RFLP) analysis was applied to the amplification products of 16S rRNA and merA genes and a specific restriction patterns was successfully obtained after treatment with different endonucleases. A small-scale reservoir of Luria Bertani (LB) medium supplemented with 30 μg/mL of HgCl2 was designed to check the detoxification ability of the selected strains. The results demonstrated 83% detoxification of mercury by both B. cereus AZ-2 and B. cereus AZ-3, and 76% detoxification by Bacillus sp. AZ-1 (p<0.05)

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries