Bangladesh Journal of Microbiology

Hospitalized Coronavirus Disease 2019 (Covid-19) with Pre-existing Diabetes Mellitus: Comparison between Survived and Deceased Patients

2023-01-19T03:48:12+00:00

Patients with pre-existing diabetes mellitus (DM) are at high risk of severe outcomes from coronavirus disease 2019 (COVID-19). However, there is limited data on these patients from South Asia, especially Bangladesh. Besides, comparative studies between survived and deceased patients with DM and COVID-19 are rare in literature. This retrospective cross-sectional study was conducted among RT-PCR confirmed COVID-19 patients with pre-existing DM in a specialized COVID-19 hospital in Bangladesh. Data from hospital records were analyzed. Among 921 RT-PCR confirmed patients with COVID-19 admitted during the study period, 231 (~25%) patients had pre-existing DM. The overall mortality and intensive care unit (ICU) mortality rate among patients with DM was 11.3% (26/231) and 46.2% (12/26), respectively. The median age of the deceased patients was slightly higher (63.5 vs. 59 years, p 0.21). The most common comorbidity in both groups was hypertension. The clinical features were not significantly different between survived and deceased. However, deceased patients had significantly lower blood oxygen level (85% vs. 93%, p <0.001), and higher neutrophil-lymphocyte ratio (7.9 vs. 4.5, p 0.003) and serum ferritin levels (946.0 vs. 425.0 ng/mL, p 0.03). Glycemic status was poor in both groups. This study would help identify a subgroup of diabetic patients with COVID-19 who are at higher risk of in-hospital death requiring rigorous clinical management.

Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 1-6

Carvacrol and Cinnamaldehyde as Next Generation Antimicrobial Agents against Foodborne Pathogens: Antibacterial Efficacy and Synergistic Interaction with Nisin

2023-01-19T04:01:04+00:00

Foodborne infections cause substantial issues all around the world, hence food safety is a major public health concern. The goal of this research is to provide information to the scientific community on the possible application of two plant essential oil molecules, Carvacrol (CAR) and Cinnamaldehyde (CN), as next-generation antimicrobials in the fight against foodborne pathogens. CAR and CN demonstrated outstanding dose-dependent antibacterial efficacy against 10 foodborne pathogens. Both Gram-positive and Gram-negative bacteria were suitably inhibited by the drugs. Antimicrobial activity of 10% v/v CAR and CN was much higher than that of the conventional antibiotic azithromycin (15g/disc). The study discovered that CAR and CN have very low MIC values (0.08% to 0.31% v/v), indicating that the compounds are efficacious even at very low concentrations. Even at 0.16% concentration, combining CAR and CN with Nisin (a widely available natural preservative) exhibited substantial synergism, with inhibition zones ranging from 8.5- 12.38 mm, decreasing the dose required to produce sufficient antimicrobial action. The findings imply that CAR and CN combined with nisin can be used as a natural antibacterial agent to limit the growth of foodborne pathogens and as a natural food preservative.

Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 7-14

Class 1 Integron gene harbouring multidrug resistant Pseudomonas isolates from clinical specimen

2023-01-19T04:01:09+00:00

Gram-negative Pseudomonas spp. particularly P. aeruginosa is an important pathogen in hospitalized patients, contributing to the morbidity and mortality due to its multiple resistance mechanisms. The present study was undertaken to determine the characteristics of Pseudomonas spp. isolated from pus of patients admitted in a local diagnostic center, Dhaka, Bangladesh. A total of 14 clinical isolates were obtained. Detailed biochemical tests, antibiotic resistance pattern and class 1 integron gene profiling were successfully performed. All isolates (100%) showed resistance against amoxicillin-clavulanate, ampicillin, ciprofloxacin, cephalexin, ceftriaxone, kanamycin, nitrofurantoin and rifampicin. About 35% of the isolates (n=5) showed resistance against Amoxicillin-clavulanate, ampicillin, azithromycin, amikacin, ciprofloxacin, cephalexin, co-trimoxazole, ceftriaxone, imipenem, kanamycin, nitrofurantoin and rifampicin. Only 28.5% isolates (n=4) were sensitive to Imipenem. Plasmid was observed in none of the isolates, whereas 50% of the isolates carried Class 1 Integron gene. The presence of mobile genetic element is an added threat as this enables transfer of resistance genes to sensitive isolates. The findings of this study are significant from a public health viewpoint as therapeutic options become restricted.

Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 15-19

Identification and Differentiation of Closely Related Members of Bacillus cereus Group by Multiplex PCR

2023-01-19T04:17:36+00:00

Highly similar genetic and phenotypic traits of at least eight bacterial species forming the ‘Bacillus cereus group’ create their precise identification and differentiation quite difficult. The present study explores the applicability of a previously suggested multiplex-PCR method for the accurate identification of the candidate Bacillus species. Out of the 257 Bacillus isolates collected from soil, 44 were identified as B. thuringiensis and 39 as B. cereus by chromogenic cultural method using Bacillus agar, although few of them shared similar colony characteristics. Identification by the multiplex PCR in a thermo cycler using 5 different sets of primer-pairs, however produced distinct amplification corresponding to the bacterial species. Four of those pairs, named BMSH, BCJH, BTJH and BASH were designed based on gyrB gene that produced amplicons of four different sizes: 604, 475, 299 and 253 bp and were specific for B. mycoides, B. cereus, B. thuringiensis, and B. anthracis respectively. The remaining one of the sets was used as an internal control which was a universal primerpair, BCGSH, designed targeting a housekeeping gene, groEL that could produce an amplicon of 400 bp in polymerase chain reactions for all members of the B. cereus group, When probing the chromosomes extracted from 257 Bacillus isolates by multiplex PCR; 48, 39 and 5 were identified as B. thuringiensis, B. cereus, and B. anthracis respectively, however the rest of the isolates did not any amplification. Interestingly, the phylogenetic tree, constructed based on partial sequences of 16S rRNA genes of selected isolates including the reference strain of B. thuringiensis (HD-73, sotto) could not differentiate the species, instead posited those in a single cluster. The multiplex PCR, therefore, proved to be a sensitive and reliable method for the identification of the bacterial candidates of Bacillus cereus group than that of cultural and rRNA gene sequence analyses.

Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 21-29

Metagenomic investigation of bacterial community of arsenic-prone area in the northwest region of Bangladesh

2023-01-19T04:28:12+00:00

Metagenomic analysis provides in-depth understanding of microbe mediated Arsenic (As) metabolism. The present study aims atmetagenomic analysis of the distribution, diversity, and abundance of bacteriome in arsenic affected groundwater and surrounding soils collected fromBogra district of Bangladesh. Metagenomic DNA was extracted from two groundwater samples BCW3 andBCW4 (As content10μgL-1 and 500 μgL-1, respectively), and two tube-well surrounding soil samples BSS1 and BCS5 (As content335 μgkg-1 and 492 μgkg-1),where As rich water flows off. Metagenomic analysis of six hypervariable regions of 16S rRNA gene resulted in a total of 788709 processed sequence reads and 5878 operational taxonomic units (OTUs). Bacterial richness, abundance and diversity (alpha and beta) were higher in BCW4 (85 genera) than BCW3 (19 genera) whereas both soil samples exhibited almost similar richness and diversity. Predominant genera in BCW3 were Pseudomonas, Microbacterium, Achromobacterwhereas Acinetobacter, Thiothrix, Stenotrophomonas, Paracoccus, Dechloromonas dominated in BCW4. Soils were co-dominated with more than hundreds of genera with a high relative abundance of Bacillus, Rhodoplanesand Pseudomonas.Metagenomic investigation explored potentialarsenotrophicbacteriome. Exploring microbial community might help to understand the biogeochemistry of As affected groundwater and surrounding soil environment.

Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 31-38

Behavioral, infrastructural and climate change Factors for Rising Diarrhea Episodes in Bangladesh

2023-01-19T04:28:46+00:00

More than 4.5 million people nationwide have experienced diarrhea in the country’s most recent outbreak, which began on March, 2022. About 70% to 80% of patients (of whom 23% had severe diarrhea or cholera) were hospitalized. Several factors were associated with the risk for diarrhea include; unhygienic and unsafe environment, age, low educational status of mothers, employment status, family size, income, poor handling of drinking water at household level, place of residence, unhygienic disposal method of feces and wastes, lack of personal hygiene and lack of access to sanitation facilities. In addition, etiology, influence of climate and geographical location, diagnosis capability, hygiene education, and infrastructure are strongly linked to the high frequency of diarrhea and play a crucial role in efficiently managing diarrhea. We observed that a significant proportion of people with diarrheal illnesses continue to seek care from unqualified healthcare practitioners since inaccessibility from professional healthcare providers. Dissemination of information on health education, increasing the supply of skilled healthcare providers, and low-cost and quality healthcare services may encourage more people to seek care from professional healthcare providers, thus may help reducing mortality in the country. In conclusion, the policy mechanisms to increase systems’ resilience, some engineering approaches include source, treatment, distribution, and point-of-use control measures could be implemented to manage microorganism proliferation in drinking water.

Bangladesh J Microbiol, Volume 39, Number 1, June 2022, pp 39-45