Bacterial Species and Antimicrobial Resistance of Clinical Isolates from Pediatric Patients in Yangon, Myanmar, 2020

Antimicrobial resistance (AMR) is a concern in medical care for children who have high burden of infectious diseases. We investigated the prevalence of bacterial species and their susceptibility to antimicrobials of 1019 clinical isolates from pediatric patients in a tertiary-care hospital in Yangon, Myanmar for one-year period (2020). The most frequently recovered species was Escherichia coli, followed by Klebsiella pneumoniae and Staphylococcus aureus, all of which accounted for 43% of clinical isolates, while 25% of isolates comprised non-fermenter, including Pseudomonas sp. and Acinetobacter sp. Phenotypically determined ESBL (extended-spectrum beta-lactamase)-positive rates in E. coli, K. pneumoniae, and Enterobacter sp. were 82%, 88%, and 65%, respectively. High rates of multiple drug resistance were noted for E. coli (84%), K. pneumoniae (81%), and Acinetobacter sp. (65%), associated with carbapenem resistance in 48%, 42%, and 59% of isolates, respectively. In contrast, S. aureus isolates exhibited low resistance rates (<30%) to most of antimicrobials, with 22% being resistant to oxacillin/cefoxitin. Fluoroquinolone resistance was found in most of bacterial species with different prevalence rates. The present study revealed the current status on prevalence of bacterial species causing infections in pediatric patients in Myanmar, highlighting the significance to monitor AMR among children.

Estudio de la prevalencia de Salmonella spp y Escherichia coli en huevos comerciales para consumo humano en el cantón Ibarra, para la creación de un banco de recursos microbianos de la PUCE-SI

Las enfermedades transmitidas por alimentos (ETA’s) son un problema importante en la salud pública y la prevalencia de las mismas permiten conocer la calidad higiénico-sanitaria de los alimentos. Se realizó un estudio descriptivo de corte transversal, en el cuál se muestrearon aleatoriamente 8 sitios de expendio, de los cuales 4 corresponden al denominado sector A (cadenas comerciales) y, los otros 4 del sector B (distribuidores mayoristas) de huevo comercial en la ciudad de Ibarra, es así que se escogieron al azar 10 huevos por sitio de expendio, dando así un total de 80 huevos estudiados. De cada huevo se sustrajo 3 muestras: clara, yema y cascarón; obteniendo un total de 240 muestras que se repartieron en dos grupos, cultivos para Salmonella spp., y Escherichia coli., obteniendo un total de 480 muestras procesadas para cultivo bacteriano aplicando los métodos de la Norma Técnica Ecuatoriana INEN 1529-15 e INEN 1529-8 respectivamente, para el control microbiológico de alimentos. Como resultado del análisis microbiológico se obtuvo un total de 18 muestras positivas, 10 para Salmonella spp., y 8 para Escherichia coli, con ello se procedió a realizar el aislamiento de las colonias en caldo nutritivo para posteriormente realizar la extracción de ADN. Terminada esta etapa se realizó la PCR para la amplificación del gen ADNr 16s, y con ello realizar la técnica RFLP para la detección de polimorfismos. En conclusión, se obtuvo una prevalencia del 4,16% y 3,33% para Salmonella spp., y Escherichia coli; siendo el sector B (distribuidores mayoristas) el de mayor prevalencia, además mediante la secuenciación se detectaron otras especies bacterianas correspondientes a: Pseudomonas sp, Acinetobacter sp, Enterobacter sp. Se identificó dos serotipos para Salmonella spp: S. Enteritidis y S. Typhimurium. El serotipo identificado de la bacteria Escherichia coli fue O157:H7.

BIODEGRADATION POTENTIAL OF RHIZOSPHERIC MICROORGANISMS OF RHIZOPHORA RACEMOSA IN CRUDE OIL CONTAMINATED MANGROVE SWAMP IN THE NIGER DELTA

Rhizophora racemosa (red mangrove tree) belongs to the family Rhizophoraceae; it is an important constituent of the mangrove swamp in Niger Delta, an oil producing region in Nigeria. The remediation of soils containing organic pollutants is possible with the use of microbial communities when the ecology is understood for potentials maximization. This study investigated the biodegradation potential of rhizospheric microorganisms of Rhizophora racemosa in crude oil- contaminated mangrove swamp in the Niger Delta.The total microbial count was determined by the serial dilution method. The hydrocarbon-utilizing bacteria and fungi were enumerated using Mineral Salts Agar containing crude oil as the sole carbon source. The biodegradation potential of these rhizomicrobes was determined using screen test, shake flask degradation tests, Total Organic Gas (TOG) and Total Petroleum Hydrocarbon (TPH) InfraCal Analyzer (HATR-T2 and CH). The turbidity, total organic gas (TOG-N) and total petroleum hydrocarbon were measured weekly for twenty-eight days. Hydrocarbon-degrading microbes isolated from the rhizosphere were identified as Marinococcus sp., Azotobacter sp., Acinetobacter sp. Aspergillus niger, Aspergillus flavus and Candida albicans. The highest rate of TPH reduction was recorded in Acinetobacter sp. (from 150 mg/L on day 1 to ˂0.0031 mg/L on day 14). This was followed by Candida albicans (148mg/L on day 1 to 2.68mg/L on day 28) and Aspergillus flavus (150mg/L on day 1 to 4.21mg/L on day 28) In conclusion, it can be inferred that the some rhizospheric microbes of Rhizophora racemosa can efficienctly degrade hydrocarbon up to 100% rate over a period of 28 days.

A novel enzyme synthesized by Acinetobacter sp. SM04 is responsible for zearalenone biodegradation

Zearalenone (ZEA), a non-steroidal estrogenic mycotoxin produced by multiple Fusarium species, contaminates cereals and threatens the health of both humans and animals by inducing hepatotoxicity, immunotoxicity, and genotoxicity. A new alkali tolerant enzyme named Ase, capable of degrading ZEA without H2O2, was derived from Acinetobacter sp. SM04 in this study. The Ase gene shares 97% sequence identity with hypothetical proteins from Acinetobacter pittii strain WCHAP 100004 and YMC 2010/8/T346 and Acinetobacter calcoaceticus PHEA-2, respectively. Based on the Acinetobacter genus database, the gene encoding Ase was cloned and extracellularly expressed in E. coli BL21. After degrading 88.4% of ZEA (20 μg/mL), it was confirmed through MCF-7 cell proliferation assays that Ase can transform ZEA into a non-estrogenic toxic metabolite. Recombinant Ase (molecular weight: 28 kDa), produced by E. coli BL21/pET32a(+)-His-Ase, was identified as an oxygen-utilizing and cytochrome-related enzyme with optimal activity at 60 °C and pH 9.0.

Electricity Generation from Hospital Wastewater in Microbial Fuel Cell using Radiation Tolerant Bacteria

Hospital waste is a type of hazardous waste that contains a wide range of dangerous substances, including radioactive materials. Radiation-tolerant microbes have shown an interest in treating this liquid waste. Radiation-resistant microorganisms were chosen from irradiated fermented sausage in this investigation. The activity of enzymes such as protease, lipase, and laccase was studied. For hospital wastewater treatment, a single chamber microbial fuel cell (sMFC) with a radiation-tolerant bacterial consortium was deployed. The microbial structure analysis showed the selected consortium was similar to Acinetobacter sp. The COD was removed at a rate of 90.10±0.30%, and the power density (PD) was 168.91±3.89 mW/m2. This was the first study to use the radiation-resistant Acinetobacter sp. bacterial consortia to treat hospital waste and generate power simultaneously.

Coping with oxidative stress in extreme environments: the distinctive roles played by Acinetobacter sp. Ver3 superoxide dismutases

ABSTRACTAcinetobacter sp. Ver3 is a polyextremophilic strain characterized by a high tolerance to radiation and pro-oxidants. The Ver3 genome comprises the sodB and sodC genes encoding an iron (AV3SodB) and a copper/zinc superoxide dismutase (AV3SodC), respectively; however, the specific role(s) of these genes has remained elusive. We show that the expression of sodB remained unaltered in different oxidative stress conditions whereas sodC was up-regulated in the presence of blue light. Besides, we studied the changes in the in vitro activity of each SOD enzyme in response to diverse agents and solved the crystal structure of AV3SodB at 1.34 Å, one of the highest resolutions achieved for a SOD. Cell fractionation studies interestingly revealed that AV3SodB is located in the cytosol whereas AV3SodC is also found in the periplasm. Consistently, a bioinformatic analysis of the genomes of 53 Acinetobacter species pointed out the presence of at least one SOD type in each compartment, suggesting that these enzymes are separately required to cope with oxidative stress. Surprisingly, AV3SodC was found in an active state also in outer membrane vesicles, probably exerting a protective role. Overall, our multidisciplinary approach highlights the relevance of SOD enzymes when Acinetobacter spp. are confronted with oxidizing agents.

Molecular identification of Bifidobacterium sp. from local yoghurt and evaluation of growth inhibition activity against pathogenic bacteria

Yoghurt is a potential source of probiotic bacteria including Bifidobacterium sp. In this context, sour yoghurt sample was collected from local market in Rajshahi for molecular identification and characterization of Bifidobacterium sp. with promising antagonistic activity against pathogenic bacteria. Isolation was done on Luria broth agar media for molecular identification and revealed that isolated bacterium showed 90% similarity with Bifidobacterium sp. Antibiotic sensitivity test result revealed that isolated Bifidobacterium sp. was sensitive to erythromycin, kanamycin, gentamycin, tetracycline, ciprofloxacin, doxycycline out of eleven commercially used antibiotics. Moreover, antagonistic activity of Bifidobacterium sp. was evaluated in our present study against four pathogenic bacteriathrough disc diffusion method. Bifidobacterium sp. had relatively strong antagonistic effect (inhibition zone ≥15 mm) against Salmonella sp. with 16mm and 19mm zones of inhibition at doses of 150 and 200 μg/disc, respectively. Similarly, the isolate showed strong growth inhibitory activity against Acinetobacter sp. and E. coli with inhibition zone of 17 mm and 16 mm at dose of 200 μg/disc while moderate growth inhibitory activity was observed against Aeromonas sp. at applied four doses. Furthermore, present investigation showed that the isolated Bifidobacterium sp. had the utmost effect against Salmonella sp. and exhibited growth inhibition of understudy pathogens in such pattern Salmonella sp.>Acinetobacter sp.> E. coli> Aeromonas sp. Bangladesh J. Sci. Ind. Res.56(3), 147-154, 2021