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.
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.
Medicinal plants are important reservoirs of bioactive compounds that need to be explored systematically. Because of their chemical diversity, natural products provide limitless possibilities for new drug discovery. This study aimed to investigate the biochemical properties of crude extracts from fifteen Nepalese medicinal plants. The total phenolic contents (TPC), total flavonoid contents (TFC), and antioxidant activity were evaluated through a colorimetric approach while the antibacterial activities were studied through the measurement of the zone of inhibition (ZoI) by agar well diffusion method along with minimum inhibitory concentrations (MIC) by broth dilution method. The methanolic extracts of Acacia catechu and Eupoterium adenophorum showed the highest TPC (55.21 ± 11.09 mg GAE/gm) and TFC (10.23 ± 1.07 mg QE/gm) among the studied plant extracts. Acacia catechu showed effective antioxidant properties with an IC50 value of 1.3 μg/mL, followed by extracts of Myrica esculenta, Syzygium cumini, and Mangifera indica. Morus australis exhibited antibacterial activity against Klebsiella pneumoniae (ZoI: 25mm, MIC: 0.012 mg/mL), Staphylococcus aureus ATCC 25923 (ZoI: 22 mm, MIC: 0.012 mg/mL), Pseudomonas aeruginosa (ZoI; 20 mm, MIC: 0.05 mg/mL), and methicillin-resistant Staphylococcus aureus (MRSA) (ZoI: 19 mm, MIC: 0.19 mg/mL). Morus australis extract showed a broad-spectrum antibacterial activity, followed by Eclipta prostrata, and Hypericum cordifolium. Future study is recommended to explore secondary metabolites of those medicinal plants to uncover further clinical efficacy.
Medicinal plants have been used from the beginning of human civilization against various health complications. Dengue virus (DENV) has emerged as one of the most widespread viruses in tropical and subtropical countries. Yet no clinically approved antiviral drug is available to combat DENV infection. Consequently, the search for novel antidengue agents from medicinal plants has assumed more insistence than in previous days. This study has focused on 31 potential antidengue molecules from secondary metabolites to examine their inhibitory activity against DENV nonstructural proteins through molecular docking and pharmacokinetics studies. In this research, the wet lab experiments were tested on a computational platform. Agathisflavone and pectolinarin are the top-scored inhibitors of DENV NS2B/NS3 protease and NS5 polymerase, respectively. Epigallocatechin gallate, Pinostrobin, Panduratin A, and Pectolinarin could be potential lead compounds against NS2B/NS3 protease, while acacetin-7-O-rutinoside against NS5 polymerase. Moreover, agathisflavone (LD50=1430mg/kg) and pectolinarin (LD50=5000mg/kg) exhibited less toxicity than nelfinavir (LD50=600mg/kg) and balapiravir (LD50=824mg/kg), and the reference drugs. Further research on clinical trials is required to analyze the therapeutic efficacy of these metabolites to develop new potential drug candidates against different serotypes of DENV.
29 October 2021 in Emergency Medicine International
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 6079 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.