CTX-M-127 with I176F mutations found in bacteria isolates from Bangladeshi circulating banknotes.

Extended-spectrum beta-lactamase (ESBL)-producing organisms are widely recognized as clinically relevant causes of difficult-to-treat infections. CTX-M has formed a rapidly growing family distributed worldwide among a wide range of clinical bacteria, particularly members of Enterobacteriaceae. Circulating banknotes, exchanged daily among people, pose a potential vehicle for transmitting multidrug resistance. We screened for ESBL-carrying bacteria in the present study and reported CTX-M mutations in Bangladesh's banknotes. We sequenced the genes and performed homology modeling using the Swiss model with CTX-M-15 (4HBT) as a template. Then, we performed molecular docking of mecillinam with the template and the generated model using Autodock 4.2 (Release 4.2.6). After docking, we visually inspected the complexes built using Autodock tools for polar contacts and pi-pi interactions in PyMOL 2.5.4. Our partially sequenced blaCTX-M was related to blaCTX-M-10 and blaCTX-M-15. We observed multiple single-nucleotide substitution mutations, i.e., G613T (silent mutation), A626T (I176F), and A503G (N135D). Homology modeling showed high similarity when the model was superimposed over the template. The orientation of Asn (135) in the template and Asp (135) in the model does not show a significant difference. Likewise, Ile (176) in the template and Phe (176) in the model offer the same orientation. Our generated model could bind to Lys237, Ser240, and Asp135 residues with the lowest binding energy on docking. Our predicted binding of the mecillinam to the mutated D-135 residue in the model indicates contributions and supports previous reports proposing CTX-M-15 to CTX-M-127 mutational conversion on the mecillinum resistance phenotype.

Mixed Nanocomposite Fertilizers Influencing Endophytic Symbiosis and Nutritional and Antioxidant Properties of Oryza sativa as a Sustainable Alternative for Commercial Fertilizers.

This study investigated the comparative effects of mixed nanocomposite (MNC) fertilizers as an alternative to commercial fertilizers (CFs) on endophytic symbiosis and nutritional properties of rice grains. We synthesized MNC fertilizers with different concentrations and characterized them by using scanning electron microscopy and Fourier transform infrared spectroscopy. The CF was applied as per the method followed by local farmers; however, for MNC fertilizers both foliar and soil applications were done. Comparative analysis of growth and development, rice-endophyte symbiosis, and nutritional properties of rice grains was conducted. The panicles per hill, length of panicles, grain per panicles, 1000-grain weight, and dry matter of rice plants treated with MNC fertilizers were found to be not statistically (p > 0.05) different compared to those of CF. However, growth parameters were significantly (p < 0.05) higher in MNC fertilizer-treated crops than in CF-treated crops. Several predominant endophytes such as Penicillium spp., Aspergillus fumigatus, Rhizopus spp., and Fusarium spp. that could have significant effects on the enhancement of growth and nutritional properties of rice grains were identified in rice plants treated with MNC fertilizers at different concentrations. Contrarily, stem-associated Cercospora spp. was found in the CF-treated field and fission yeast was observed in the blank-treated field. In addition, the contents of proteins, fibers, carbohydrates, energy-yielding components, vitamin A, and minerals were significantly increased in rice plants treated with MNC fertilizers. Thus, we would like to conclude that MNC fertilizers could be one of the most potential alternatives to CFs for achieving better rice-endophyte symbiosis as well as nutritional improvements in rice grains for sustainable production.

Relative expression of proinflammatory molecules in COVID-19 patients who manifested disease severities.

Aggressive immune response, due to overexpressed proinflammatory molecules, has been characterized in coronavirus disease 2019 (COVID-19) patients. Some of those mediators have a dual and opposite role on immune systems at play behind differential disease severities. We investigated the expression of some cytokines and chemokines in COVID-19 patients in Bangladesh. We diagnosed the patients by detecting severe acute respiratory syndrome coronavirus 2 RNA in nasal swab samples by the real-time RT-PCR method. Thirty adult patients were preselected based on their disease severities and grouped into mild, moderate, and severe cases. Nine healthy volunteers participated in this study as a control. Relative expression of nine cytokines/chemokine in total leukocytes was semi-quantified in SYBRgreen-based real-time quantitative reverse-transcriptase polymerase chain reaction. We performed statistical tests on transformed log data using SPSS 24.0. At the onset of symptoms (Day 1), angiotensin-converting enzyme 2 (ACE2) (p < 0.05) and interleukin (IL)-6 (p > 0.05) were upregulated in all COVID-19 groups, although the expression levels did not significantly correlate with disease severities. However, expressions of IL-6, monocyte chemotactic protein-1, macrophage inflammatory protein-1α, tumor necrosis factor-α (TNF-α), RANTES (regulated upon activation, normal T cell expressed and secreted), and ACE2, on Day 14, were positively correlated with disease severities. Relative viral load at Day 1 showed no significant correlation with cytokine expression but had a significant positive correlation with RANTES and ACE2 expression on Day 14 (p < 0.05). Male patients had a higher level of IL-6 than female patients on Day 1 (p < 0.05). All COVID-19 patients showed upregulated cytokines and chemokines on Day 14 compared to Day 1 except TNF-α. Female patients had a higher expression of ACE2 and IL-12 on Day 14. Upregulated cytokines/chemokines at the convalescent stage, especially IL-6, may help in targeting anticytokine therapy in post-COVID-19 patients' management.

Prevalence and stability of SARS-CoV-2 RNA on Bangladeshi banknotes.

Originating in December 2019 in China, SARS-CoV-2 has emerged as the deadliest pandemic in humankind's history. Along with direct contact and droplet contaminations, the possibility of infections through contaminated surfaces and fomites is investigating. This study aims to assess SARS-CoV-2 viral RNA's prevalence by real-time one-step reverse transcriptase PCR on banknotes circulating in Bangladesh. We also evaluated the persistence of the virus on banknotes spiked with SARS-CoV-2 positive diluted human nasopharyngeal samples. Among the 425 banknote samples collected from different entities, 7.29% (n = 31) were tested positive for targeted genes. Twenty-four positive representative samples were assessed for n gene fragments by conventional PCR and sequenced. All the samples that carry viral RNA belonged to the GR clade, the predominantly circulating clade in Bangladesh. In the stability test, the n gene was detected for up to 72 h on banknotes spiked with nasopharyngeal samples, and CT values increase significantly with time (p < 0.05). orf1b gene was observed to be less stable, especially on old banknotes, and usually went beyond detectable limit within 8 to 10 h. The stability of virus RNA well fitted by the Weibull model and concave curve for new banknotes and convex curve for old banknotes revealed. Handling banknotes is unavoidable; hence, these findings imply that proper hygiene practice is needed to limit SARS-CoV-2 transmission through banknotes.

Analysis of diarrheagenic potential of uropathogenic Escherichia coli isolates in Dhaka, Bangladesh.

INTRODUCTION: Urinary tract infection is the most frequently diagnosed kidney and urologic disease. METHODOLOGY: Whether the Escherichia coli strains responsible for urinary tract infection (UPEC) carry virulence properties of diarrheagenic E. coli (DEC), 56 UPEC strains were examined for the presence of DEC and UPEC characteristics (e.g. biofilm formation, hemolysis activity, virulence genes). RESULTS: Among 56 UPEC strains, 21 showed capable of biofilm formation and only 5 showed hemolysis activity on sheep blood agar. In Multiplex PCR on assessment of virulence genes related to uropathogenesis; 42% was found positive for papC gene, 27% was fim1 positive, 11% was afa positive and none was found positive for sfa. Most of the isolates were found carrying none of eight diarrhea associated genes (e.g. estA, eltB, vt1, vt2, eaeA, ea, ial and bfpA) as expected. Only seven isolates were found to harbor these genes: five genes i.e., vt2, ial, eltB, bfpA and ea were found in five different isolates and two isolates were positive for estA, among these two, one was found positive for fim1, papC along with estA, a UPEC strain containing virulent gene of ETEC strain. One isolate was found carrying fim1 and vt2 showing the property of EHEC and another isolate was found positive for fim1 and ial, the characteristic of EIEC. One isolate harboring bfpA gene characterized as EPEC and the another one was found to harbor ea gene, characterized as EAEC. CONCLUSIONS: This study observed that most UPEC strains are unique to uropathogenesis, still very few may carry the diarrheagenic property.

Contribution of target alteration, protection and efflux pump in achieving high ciprofloxacin resistance in Enterobacteriaceae.

The study aims at revealing the comprehensive contribution of target alteration, target protection and efflux pump to the development of high level of ciprofloxacin (CIP) resistance in Enterobacteriaceae bacteria of environmental, clinical and poultry origins. Antibiotic susceptibility test was used to detect CIP resistant (CIPR) isolates and MICCIP was determined by broth microdilution method. The presence of qnrS gene was identified by PCR and Southern blot hybridization (SBH) confirmed their location. Checkerboard titration demonstrated the effect of NMP on CIP action. PCR followed by sequencing and in silico analysis revealed the contribution of mutations in acrR, marR and gyrA to CIPR development. Out of 152 isolates, 101 were detected as CIPR. Randomly selected 53 isolates (MICCIP 4-512 µg/mL) were identified as Escherichia spp. (26), Enterobacter spp. (7), Klebsiella spp. (5) and Salmonella spp. (15) and of them 31 isolates carried qnrS. qnrS harboring 18 highly CIPR isolates (MICCIP: 256-512 µg/mL) were selected for further study. SBH confirmed 7 isolates harbored qnrS gene in plasmids. The acrA, acrB and tolC were present in all 18 isolates and NMP had an additive (12-isolates) or synergistic (6-isolates) effect on CIP action. Most isolates contained double amino acid (aa) substitutions (S83L and D87N) in QRDR of GyrA resulting in an altered conformation of putative CIP binding pocket. However, some isolates contained single (S83L or S83Y) or no aa substitution but showed high CIPR implicating that the concerted action of three mechanisms is responsible for high CIPR with the most significant role of efflux pump.

Serological cross-reaction between O-antigens of Shigella dysenteriae type 4 and an environmental Escherichia albertii isolate.

An environmental freshwater bacterial isolate, DM104, appearing as Shigella-like colonies on selective agar plates was found to show strong and specific serological cross-reactivity with Shigella dysenteriae type 4. Biochemical identification according to the analytical profile index, molecular serotyping by restriction of the amplified O-antigen gene cluster (rfb-RFLP), together with phylogenetic analysis of the 16S rRNA gene and multi-locus sequence analysis, identified the isolate as Escherichia albertii. rfb-RFLP of DM104, revealed a profile different from that of S. dysenteriae type 4. However, western blot analysis of extracted lipopolysaccharides demonstrated strong cross-reactivity with S. dysenteriae type 4 using specific monovalent antisera and a lipopolysaccharide gel banding profile similar to that of S. dysenteriae type 4. The observed O-antigen cross-reaction between an E. albertii isolate and S. dysenteriae extends our knowledge of the extent of O-antigen cross-reaction within the Escherichia/Shigella group of organisms, and offers the possibility of using DM104 and similar cross-reacting strains as shigellosis vaccine candidates.