The emergence of multidrug resistant (MDR) bacteria which is attributable to extended spectrum β-lactamases (ESBLs) production of CTX-M types is an obvious problem worldwide. This study is aimed at determining the prevalence of CTX-M β-lactamases producing multidrug resistant Escherichia coli and Klebsiella pneumoniae among patients attending Bir Hospital. A cross-sectional study was conducted between April and September 2019 at Bir Hospital, Kathmandu, and Department of Microbiology, National College, Kathmandu, Nepal. A total of 5,690 different clinical specimens were subjected to cultural, microscopic, and biochemical analyses for the identification of the isolates. Antimicrobial susceptibility testing of the isolates was done, and MDR isolates were selected and processed for further ESBL confirmation by the combination disks method. All confirmed ESBL isolates were screened for CTX-M type β-lactamases (blaCTX-M) by PCR. Of the total 345 isolates (227 Escherichia coli and 118 Klebsiella pneumoniae), 232 were MDR. All 232 (67.24%) MDR isolates were suspected as ESBL producers on the screening test. However, on the phenotypic test, 135 (58.18%) of total MDR bacteria were confirmed as ESBL producers with the highest proportion in K. pneumoniae (59.37%). The major source of ESBL producers was urine. ESBL producing isolates were mostly identified from outpatients and patients belonging to age group 41-60. Gentamicin was found to be effective against ESBL producers. The prevalence of blaCTX-M was (89.62%) with the highest frequency for E. coli (93.81%). High prevalence of ESBL of CTX-M types among MDR E. coli and K. pneumoniae was detected from clinical specimens of patients in Bir Hospital. This study warrants the need for the judicious use of antibiotics as well as emphasize the use of modern diagnostic tools for the early detection of MDR and ESBL producers to curb the emergence and spread of MDR and ESBL producing bacteria in the clinical settings of Nepal.

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Dengue, a mosquito-borne viral infectious disease, causes a high morbidity and mortality in tropical and subtropical areas of the world. In Nepal, the first case of dengue was reported in 2004 followed by frequent outbreaks in subsequent years, with the largest being in 2019 taking the death toll of six. It is reported that the number of dengue fever cases are soaring in Nepal spreading from the plains to more hilly regions. This might have serious public health implications in the future when combined with other factors, such as: global warming, lack of early detection and treatment of dengue, lack of diagnostic facilities, poor healthcare systems and mosquito control strategies. Nepal, thus, needs a cost-effective mosquito control strategy for the prevention and control of dengue. The Wolbachia-mediated biological method of the dengue control strategy is novel, economic, and environment-friendly. It has been successfully trialed in several areas of dengue-prone countries of the world, including Australia, Malaysia, Vietnam etc. resulting in significant reductions in dengue incidence. Given the lack of effective vector control strategy and weak economic condition of the country along with the persistence of climate and environment conditions that favors the host (Aedes mosquito) for Wolbachia, this approach can be a promising option to control dengue in Nepal.

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Objective: Di-2-ethylhexyl phthalate (DEHP) pollution is one of the major environmental concerns all over the world. This research aimed at studying the biodegradation kinetics of DEHP by a newly isolated bacterial strain. Water and sediment samples were collected from Wuhan South Lake and potent bacterial isolates were screened for DEHP degradation, characterized by biochemical, physiological, morphological and 16S rDNA gene sequencing, and optimized under suitable pH, temperature, NaCl and DEHP concentrations. DEHP and its metabolites were quantified by High Performance Liquid Chromatography and their degradation kinetics were studied. Results: The newly isolated bacterium was identified as Ochrobactrum anthropi strain L1-W with 99.63% similarity to Ochrobactrum anthropi ATCC 49188. It was capable of utilizing DEHP as the carbon source. The optimum growth temperature, pH, DEHP and NaCl concentration for the strain L1-W were 30 °C, 6, 400 mg/L and 10 g/L respectively. Strain L1-W was capable of degrading almost all (98.7%) of DEHP when the initial concentration was 200 mg/L within a period of 72 h. Besides, it was also found capable of degrading five other phthalates, thus making it a possible candidate for bioremediation of phthalates in the environmental settings.

Background: Antimicrobial resistance is a global threat in the medical society. Extended-Spectrum β-lactamase (ESBL) producing bacteria are increasing worldwide including Nepal and causing more severe infections because of their continuous mutation and multidrug resistance (MDR) nature. Objective: The objective of this study was to assess Gram-negative bacterial etiology of lower respiratory tract infections (LRTIs) and determine their antibiotic susceptibility pattern with a special focus on MDR including ESBL production. Methods: A total of 109 sputum specimens were analyzed. The bacterial isolates were identified by standard microbiological procedures including Analytical Profile Index (API) 20E test panels for Enterobacteriaceae and subjected to antimicrobial susceptibility testing. Screening of ESBL producers among Gram-negative isolates was done by using third generation cephalosporins (ceftazidime and cefotaxime) and confirmed by the combined disk method as recommended by CLSI (2019). Results: Out of 109 sputum specimens, Gram-negative bacterial etiology was determined in 31(28.4%) cases. The age-wise distribution of LRTIs patient was found to be statistically significant with bacterial incidence (p < 0.05). Altogether, 15(46.9%) isolates were multidrugresistant. ESBL producers were observed only among Klebsiella spp. and Escherichia coli isolates. On the ESBL screening test of 9 isolates (3 of E. coli and 6 of Klebsiella spp.,) 5(55.6%) gave a positive result, and only 3(33.3%) of them were further confirmed as ESBL producers. The majority of ESBL producers were Klebsiella spp. 2(66.7%). Conclusion: The present study revealed that multidrug resistance is prevalent among Gramnegative bacterial pathogens isolated from the patients with lower respiratory tract infections, requiring routine laboratory testing for MDR and ESBL production in clinical isolates for better prophylaxis and reducing the risk of ESBL transmission.

The multidrug- or extensively drug-resistant (MDR/XDR) Pseudomonas aeruginosa carrying some virulence genes has become a global public health threat. However, in Nepal, there is no existing report showing the prevalence of oprL and toxA virulence genes among the clinical isolates of P. aeruginosa. Therefore, this study was conducted for the first time in the country to detect the virulence genes (oprL and toxA) and antibiotic susceptibility pattern of P. aeruginosa. A total of 7,898 clinical specimens were investigated following the standard microbiological procedures. The antibiotic susceptibility testing was examined by the modified disc diffusion method, and virulence genes oprL and toxA of P. aeruginosa were assessed using multiplex PCR. Among the analyzed specimens, 87 isolates were identified to be P. aeruginosa of which 38 (43.68%) isolates were reported as MDR. A higher ratio of P. aeruginosa was detected from urine samples 40 (45.98%), outpatients’ specimens 63 (72.4%), and in patients of the age group of 60–79 years 36 (41.37%). P. aeruginosa was more prevalent in males 56 (64.36%) than in female patients 31 (35.63%). Polymyxin (83.90%) was the most effective antibiotic. P. aeruginosa (100%) isolates harboured the oprL gene, while 95.4% of isolates were positive for the toxA gene. Identification of virulence genes such as oprL and toxA carrying isolates along with the multidrug resistance warrants the need for strategic interventions to prevent the emergence and spread of antimicrobial resistance (AMR). The findings could assist in increasing awareness about antibiotic resistance and suggest the judicious prescription of antibiotics to treat the patients in clinical settings of Nepal.

Microbially produced gamma poly glutamic acid (γ–PGA) is a commercially important biopolymer with many applications in foods and various other substances and are abundantly used in different parts of the world. With an aim to study the potent γ–PGA producing Bacillus species, a total of 47 different samples ( Kinema , soil, and water) were randomly collected from different locations across the country, and Bacillus sp. were selectively isolated, screened, and characterized by performing physiological, biochemical, morphological, and 16S rRNA gene sequencing. The microbial production of γ–PGA was assayed with the selected isolates on the PGA medium and the metabolite obtained was recovered by ethanol precipitation method and further characterized by thin-layer chromatography (TLC). Thermotolerance (25–60 °C), pH tolerance (4–9), and NaCl tolerance (1–9%) tests were performed to optimize the bacterial growth and γ–PGA production and its viscosity were measured by Ostwald's viscometer. Out of 145 randomly selected colonies, 63 isolates were Gram-positive, rods, and endospore producers and were presumptively confirmed as genus Bacillus. Higher growth of γ–PGA producers were reported in 22 isolates and was found at optimum conditions such as temperature (30–37 °C), pH (6.5–7), incubation time (3 days), and NaCl concentration (3%) and γ–PGA thus produced was further verified by TLC with the retention factor (RF) value 0.27. The potent isolates were closely similar to Bacillus subtilis subsp . stercoris , Bacillus cereus , Bacillus paranthracis, and Bacillus licheniformis etc . Based on the findings of the study, B . licheniformis is the most potent γ–PGA producing Bacillus sp. which can further be used for the commercial production of γ–PGA. To the best of our knowledge, there is yet no published research from Nepal showing the production of the γ–PGA although microbially produced γ–PGA are the major constituents in some popular foods in particular communities of the country.