Epidemiological Features of Leptospirosis and Identification of Leptospira wolffii as a Persistently Prevailing Species in North-Central Bangladesh.

Leptospirosis is considered to be the most widespread, yet neglected, re-emerging zoonotic disease caused by infection with a pathogenic species of the genus Leptospira. Although this disease is prevalent in Bangladesh, the recent epidemiological status has not yet been well documented. In this study, we aimed to determine the prevalence of leptospirosis among febrile patients using different diagnostic methods and to characterize the epidemiological features and species of Leptospira in Mymensingh, north-central Bangladesh. Among the blood samples of 186 patients with suspected leptospirosis who met the inclusion criteria, including having a fever for more than 5 days (November 2021-June 2022), 88 samples (47%) were Leptospira-positive according to IgM LAT, IgM ELISA, or nested PCR (positivity rates: 38%, 37%, and 42%, respectively). Nested PCR showed a significantly higher positivity rate (54%) in patients with a short fever (5-10 day) than the other methods did, with lower rates among those with a longer fever. Leptospirosis cases were more common in males (68%), those 16-45 years of age (70%), residents of rural areas (81%), and farmers (41%). In addition to a fever, myalgia and jaundice were found in more than 70% of the patients, while variable symptoms were observed. The 16S rRNA sequencing analysis revealed that the Leptospira species in all the 22 samples tested were L. wolffii, belonging to the pathogenic subclade P2. This study showed the recent epidemiological features of leptospirosis in Bangladesh, indicating the presumptive predominance of L. wolffii since 2019.

The reality of the use of growth hormones in fish (Rui (Labeo rohita), Catla (Catla catla), and Monosex Tilapia (Oreochromis niloticus) production.

The unobservable use of hormones in fish production is becoming an alarming issue worldwide. To reveal the fact in Bangladesh, 144 fish samples (rui (Labeo rohita), catla (Catla catla), and monosex tilapia (Oreochromis niloticus)) were collected from different fish farms and markets of Mymensingh district. The market samples had two sources (Mymensingh and Rajshahi district). The steroid hormonal (testosterone, estrogen, and progesterone) residue was analyzed by HPLC-UV detection. A standard questionnaire survey was conducted where most farmers (80%) denied using the hormone in fish production. Among the analyzed samples of all three fishes, hormonal residues were detected in approximately 98% of samples, and around 92% contained residues above the ADI. Among the contaminated samples, 70% of samples had a single residue and 30% had multiple residues. The testosterone and progesterone hormonal residue was detected in all three fishes in both farm and market samples and ranged (above ADI) from 2.1 to 16.96 µg/kg and 31.47-731.57 µg/kg (p < 0.05) respectively. The estrogen hormone residue was only detected in market samples (Rajshahi district) of rui and catla and no residue was detected in tilapia fish and the hormone level (above ADI) ranged from 8.23 to 40.13 µg/kg. This study revealed that the use of hormones varies on the attitude of farmers based on the local culture pattern as estrogen hormone residue was only detected in market samples. The consumption of contaminated fish at such concentrations may cause many health hazards in humans, especially in children. Thus, this study reveals a new alarming fact to focus on, and an effective monitoring system should be implemented as soon as possible for public health concerns.

Pesticides in vegetable production in Bangladesh: A systemic review of contamination levels and associated health risks in the last decade.

This paper reviewed the published data on the levels of different pesticide residues in vegetables (tomato, eggplant, beans, gourds, cauliflower, cabbage, cucumber, potato, carrot, onion, red chilli, red amaranth, lady's finger, spinach, coriander, and lettuce) from Bangladesh in the last decade. Vegetable production in Bangladesh has increased tremendously (37.63%) compared to the last decades, along with its pesticide use. The most observed pesticide groups used in vegetable production were organophosphorus, pyrethroids, carbamate, organochlorine, nereistoxin analogue group, and neonicotinoids. More specifically, chlorpyrifos, dimethoate, diazinon, and malathion were the most used pesticides. More than 29% of the vegetable samples (1577) were contaminated with pesticide residue; among the contaminated samples (458), most cases (73%) exceeded the maximum residue limits (MRLs). The pesticide-contaminated vegetables were cucumber (51%), tomato (41%), cauliflower (31%), miscellaneous vegetables (36%), eggplant (29%), beans (23%), cabbage (18%), and gourds (16%). Among the pesticide-contaminated samples, vegetables with above MRL were gourds (100%), beans (92), tomato (78%), eggplant (73%), miscellaneous vegetables (69%), cucumber (62%), cabbage (50%), cauliflower (50%) (p < 0.05). It was also observed that a single vegetable was often contaminated with multiple pesticides, and farmers did not follow a proper withdrawal period while using pesticides. Hazard quotation (HQ>1) was observed in adolescents and adults in tomato, eggplant, beans, cauliflower, cabbage, cucumber, lady's finger, lettuce, and coriander. There was no health risk observed (HQ<1) in gourds, potato, carrot, onion, red chilli, red amaranth, spinach, and okra. The highest acute and chronic HQ (aHQ, cHQ) was observed for cypermethrin (bean) in adolescents (aHQ=255, cHQ= 510) and adults (aHQ=131, cHQ=263). It was also observed that these pesticides harmed air, soil, water, and non-target organisms. Nevertheless, the review will help the government develop policies that reduce pesticide use and raise people's awareness of its harmful effects.

Prevalence and Antifungal Susceptibility of Clinically Relevant Candida Species, Identification of Candida auris and Kodamaea ohmeri in Bangladesh.

Candida species are major fungal pathogens in humans. The aim of this study was to determine the prevalence of individual Candida species and their susceptibility to antifungal drugs among clinical isolates in a tertiary care hospital in Bangladesh. During a 10-month period in 2021, high vaginal swabs (HVSs), blood, and aural swabs were collected from 360 patients. From these specimens, Candida spp. was isolated from cultures on Sabouraud dextrose agar media, and phenotypic and genetic analyses were performed. A total of 109 isolates were recovered, and C. albicans accounted for 37%, being derived mostly from HVSs. Among non-albicans Candida (NAC), C. parapsilosis was the most frequent, followed by C. ciferrii, C. tropicalis, and C. glabrata. Three isolates from blood and two isolates from aural discharge were genetically identified as C. auris and Kodamaea ohmeri, respectively. NAC isolates were more resistant to fluconazole (overall rate, 29%) than C. albicans (10%). Candida isolates from blood showed 95% susceptibility to voriconazole and less susceptibility to fluconazole (67%). Two or three amino acid substitutions were detected in the ERG11 of two fluconazole-resistant C. albicans isolates. The present study is the first to reveal the prevalence of Candida species and their antifungal susceptibility in Bangladesh.

Drug Resistance Determinants in Clinical Isolates of Enterococcus faecalis in Bangladesh: Identification of Oxazolidinone Resistance Gene optrA in ST59 and ST902 Lineages.

Enterococcus faecalis is one of the major causes of urinary tract infection, showing acquired resistance to various classes of antimicrobials. The objective of this study was to determine the prevalence of drug resistance and its genetic determinants for E. faecalis clinical isolates in north-central Bangladesh. Among a total of 210 E. faecalis isolates, isolated from urine, the resistance rates to erythromycin, levofloxacin, and gentamicin (high level) were 85.2, 45.7, and 11.4%, respectively, while no isolates were resistant to ampicillin, vancomycin and teicoplanin. The most prevalent resistance gene was erm(B) (97%), and any of the four genes encoding aminoglycoside modifying enzyme (AME) were detected in 99 isolates (47%). The AME gene aac(6')-Ie-aph(2")-Ia was detected in 46 isolates (21.9%) and was diverse in terms of IS256-flanking patterns, which were associated with resistance level to gentamicin. Tetracycline resistance was ascribable to tet(M) (61%) and tet(L) (38%), and mutations in the quinolone resistance-determining region of both GyrA and ParC were identified in 44% of isolates. Five isolates (2.4%) exhibited non-susceptibility to linezolide (MIC, 4 µg/mL), and harbored the oxazolidinone resistance gene optrA, which was located in a novel genetic cluster containing the phenicol exporter gene fexA. The optrA-positive isolates belonged to ST59, ST902, and ST917 (CC59), while common lineages of other multiple drug-resistant isolates were ST6, ST28, CC16, and CC116. The present study first revealed the prevalence of drug resistance determinants of E. faecalis and their genetic profiles in Bangladesh.