Microbiology insights最新文献

Multidrug resistance and invasiveness of non-typhoidal Salmonella (NTS) serovars have in recent times brought to the fore the public health risk associated with salmonellosis. This study was aimed at profiling NTS serovars isolated from food animals and humans for their susceptibility to antibiotics and plasmid replicon types. Forty seven NTS serovars were profiled for their susceptibility to antibiotics using the disk diffusion method. Polymerase chain reaction based replicon typing assay was used for profiling plasmid replicon types detected in Salmonella isolates. High rate of resistance were found for amoxicillin/clavulanic acid (40/47; 85.1%), cefuroxime (38/47; 80.9%) and ceftazidime (30/47; 63.8%). Thirty one (65.9%) and 33 (70.2%) showed intermediate resistance to ofloxacin and ciprofloxacin respectively. Plasmids of sizes ranging from 14.3 to 16.7 kb were detected in 24 (51.1%) of Salmonella isolates with some serovars harbouring multiple plasmids. FIA, FIB, Frep and W plasmid replicon types were detected in 11, 4, 2 and 1 of the Salmonella isolates respectively. Three of the isolates harboured both FIA and FIB replicon types. The high rate of resistance to β-lactams observed in Salmonella serovars harbouring different plasmid replicon types in this study highlight potential public health threat and the need for prudent use of antibiotics in human and veterinary medicine.

Chryseobacterium indologenes is gram-negative bacteria that cause infection in humans. It is less frequently isolated in the laboratory. The development of drug-resistant and its intrinsic ability to resist a wide range of antimicrobials enables them to cause mortality in an immunocompromised patient with a longer hospital stay. Our study objectives are to investigate antimicrobial-resistant patterns, drug-resistant enzymes, and the risk factor analysis associated with multidrug-resistant (MDR), extensively drug-resistant (XDR), and Pan-drug resistant (PDR) within 2 years. Altogether 53 strains of Chryseobacterium indologens were obtained from 5000 specimens that were processed for routine bacterial culture. The bacterial identification was done using conventional techniques (colony morphology, gram staining, flexirubin test, and biochemical tests) as well as the VITEK-2 System to further confirm. The bacterial isolate were processed to observe antimicrobial susceptibility test (AST) using disk diffusion method. MDR XDR and PDR were classified following European Centre for Disease Prevention and Control guidelines. C. indologens strains with beta-lactamases such as extended-spectrum beta-lactamases (ESBL), metallo beta-lactamases (MBL), and Amp-C beta-lactamases (Amp-C) were detected phenotypically. The highest isolation of C. indologens was observed in a sputum sample. In vitro antimicrobial susceptibility test revealed susceptibility to tigecycline followed by levofloxacin, cotrimoxazole, and piperacillin-tazobactam. From 53 isolates of C. indologens, MDR accounts for 56.60% and 22.64% for XDR. Combined antimicrobial therapy and longer hospital stay were found to be the leading risk factor. All 53 C. indologenes strains were detected as MBL. Total ESBL was detected in 16.98% of MBL producer strains and Amp-C was observed in 13.20% of MBL-producing strains. All 3 enzyme co-oproducers were seen in only 5.66% of C. indologens. Although it is rarely encountered in the laboratory, it showed a remarkable effect in patients with underlying predisposing factors and prolonged hospital stays. The presence of betalactamases determined the drug-resistant activity on a wide spectrum of tested antibiotics.

Background: Laboratory work provides students with the ability to process skills, perform experiments and tests, and interpret experimental data. Instead of traditional teaching methods, there are good laboratory experiences to develop a conceptual understanding of science. A lack of laboratory safety requirements and practice can affect the health of students, staff, and the environment. Therefore, the current study provides updated safety requirements and practice information.

Objective: The purpose of this study was to evaluate safety requirements and practices among teaching laboratories at the Health Institute 2021.

Methods: An institutional-based descriptive study design was conducted on November 15-20, 2020, among staff members of the Bule Hora University Institute of Health. Seventeen randomly selected academic staffs and laboratory assistants from 2 departments participated in the study. Data were collected through a self-administered questionnaire and an observational checklist. Finally, the data were coded and entered into Statistical Package for Social Sciences (SPSS) version 20 for analysis. Data were then analyzed using simple quantitative descriptions such as frequency counts and percentages. The data are presented in a table.

Results: Of the safety requirements evaluated, only 33.3% (6) were available in the laboratory. Of the safety practices evaluated, 44.6% were used all the time, 37.7% were used occasionally, and 17.6% were never practiced in the laboratory by the respondents. Of his respondents, 58.8% had never been regularly inspected for laboratory safety, and 77% had never received training in laboratory safety. Observations show that teaching laboratories in health organizations lack safety manuals/first aid diaries or guidelines, laboratory building drainage systems, adequate ventilation, water flow, and appropriate laboratory sizes.

Conclusions: This study reveals poor laboratory safety practices and safety requirements in teaching laboratories. These limitations may cause health problems, environmental pollution, contamination, and chemical spills. Stakeholders should improve safety requirements and create awareness among staff, students, and lab assistants.

The ability of pathogenic Escherichia coli to produce carbapenemase enzymes is a characteristic that allows them to resist various antibiotics, including last-resort antibiotics like colistin and carbapenem. Our objectives were to identify rapidly developing antibiotic resistance (AR), assess β-lactamases production, and detect mcr-1 and bla _NDM-1 genes in the isolates. A prospective cross-sectional study was carried out in a referral hospital located in Kathmandu from November 2019 to December 2020 using standard laboratory and molecular protocols. Among 77 total E. coli isolates, 64 (83.1%) of them were categorized as MDR. Phenotypically 13 (20.3%) colistin-resistant, 30 (46.9%) ESBL and 8 (12.5%) AmpC producers, and 5 (7.8%) ESBL/AmpC co-producers were distributed among MDR-E. coli. Minimum inhibitory concentrations (MIC) against the majority of MDR isolates were exhibited at 1 g/L. Of these 77 E. coli isolates, 24 (31.2%) were carbapenem-resistant. Among these carbapenem-resistant bacteria, 11 (45.9%) isolates were reported to be colistin-resistant, while 15 (62.5%) and 2 (8.3%) were MBL and KPC producers, respectively. Out of 15 MBL producers, 6 (40%) harbored bla _NDM-1, and 8 (61.5%) out of 13 colistin-resistant pathogens possessed mcr-1. The resistance by colistin- and carbapenem were statistically associated (P < .001). However, only 2 (18.2%) of the co-resistant bacteria were found to have both genes. Our study revealed the highly prevalent MDR and the carbapenem-resistant E. coli and emphasized that the pathogens possess a wide range of capabilities to synthesize β-lactamases. These findings could assist to expand the understanding of AR in terms of enzyme production.

Typhoid is a major public health concern. Even though antibiotics are usually used to treat typhoid fever, the spread of multi drug resistant Salmonella typhi is making antibiotics much less effective. This study was conducted to assess the prevalence of multidrug-resistant Salmonella typhi from the clinical samples. During this study, 154 blood samples of suspected typhoid patients were collected from the hospital and diagnostic center located in Chattogram City, Bangladesh. Isolation and identification of Salmonella typhi was done by both biochemical tests. PCR analysis was also done for the confirmation of biochemical result. Antimicrobial susceptibility test was performed according to the Kirby-Bauer disk diffusion method against ampicillin, chloramphenicol, cefepime, cotrimoxazole, ceptriaxone, ciprofloxacin, nalidixic acid, and azithtomycin. Out of 154, 21 (13.64%) isolates were identified as Salmonella typhi and the prevalence of typhoid in Chattogram, Bangladesh was 13.64% (n = 21). It was also found that children under the age of 5 are the more vulnerable target of Salmonella typhi infection. Antibiotic resistance profiling revealed 85% isolates were Multi-Drug Resistant (MDR) and highest resistance was found in case of Nalidixic acid. Although, most of the isolated Salmonella typhi were MDR, first generation antibiotics Co-trimoxazile, Chloramphenicol, and Ampicillin were found effective against Salmonella typhi.

Background: Early detection of post-COVID-19-related lung fibrosis is very important for the early introduction of treatment and to minimize morbidity and mortality. The aim of this study is the early detection and evaluation of post-COVID-19 fibrosis by high-resolution computed tomography (HRCT).

Methods: This prospective study included 115 patients irrespective of age and sex, who tested positive for the SARS-CoV-2 by nasopharyngeal swab (RT PCR), admitted to the Dhaka North City Corporation (DNCC) dedicated COVID-19 hospital, Dhaka, and discharged after recovery. Patients went through a chest HRCT scan at least once during their hospital stay and another scan during follow-up after hospital discharge and 8 to 12 weeks of negative RT-PCR report.

Result: Among 100 patients 23 patients had >50% of total lung involvement by visual assessment. Thirty-three patients had 25% to 50% of total lung volume involvement. Twenty-seven patients had less than 25% of total lung involvement, whereas 17 patients had no visual fibrotic change on the follow-up HRCT scan. A statistical association was found between age, gender, smoking, and severe form of lung fibrosis (P < .05). Patients with mild CT severity score (⩽8) had a very good prognosis. Patients who were admitted to the hospital for more than 15 days were more prone to developing moderate and severe forms of fibrosis. Patients who received at least 2 doses of the COVID-19 vaccine had less severe forms of fibrosis as well as more cases of complete radiological recovery. On the HRCT scan, most of the patients had bilateral, peripheral (68%), and predominant mid & lower lobar parenchymal involvement.

Conclusion: Early detection and HRCT evaluation of post-COVID-19 related lung fibrosis is very crucial for early management and introduction of anti-fibrotic drugs.

In developing countries, an estimated 80% of the population use traditional herbal medicines as part of their primary health care. As the market for herbal medicine expands in many African countries, partly due to their use in the treatment of COVID-19, there is the need to address all the associated safety issues. The aim of the study was to evaluate the microbial contamination of locally prepared, as well as imported foreign herbal products sold in Accra. Standard microbiological methods were employed in the enumeration of coliforms and the identification of pathogenic microbes in 60 herbal preparations that were sampled. A larger proportion (76.7%) of local herbal preparations was contaminated with bacteria as compared with imported ones (63.3%). Bacillus species and Pseudomonas aeruginosa were the predominant bacteria obtained from foreign and locally manufactured herbal preparations, respectively. A proportion of 36.7% (11) of the local samples were positive for coliform and the coliform counts ranged from 3.0 × 10¹ cfu/ml to 2.0 × 10⁴ cfu/ml. Two foreign herbal samples (6.7%) were positive for coliforms; one had a count of 1.7 × 10⁵ cfu/g while the other had 2 × 10⁴ cfu/g. Herbal preparations sold in markets of Accra harbour several microbial pathogens; the risk is relatively higher for locally produced herbal preparations compared to imported herbal preparations. As a result, it is recommended that quality assurance in the production of local herbal preparations should be thoroughly monitored from the beginning of production to the final selling of the preparations. There is also the need to strengthen microbiological safety monitoring of imported herbal preparations.

Mycotoxin contamination is a major food safety drawback towards the commercialization of food products. The commercialization of khadi, a popular fermented alcoholic beverage of Botswana necessitates the investigation of the presence of mycotoxins. Khadi brewing involves the uncontrolled and unstandardized spontaneous fermentation of sun-dried Grewia flava fruits, which could be a source of mycotoxin-producing filamentous fungi (molds). This study sought to investigate the presence of mycotoxins producing fungi and mycotoxins in 18 samples of khadi collected in Central and Northern Botswana. Periconia thailandica, Cladosporium cladosporioides, Aspergillus ochraceus, Phoma eupyrena, Setosphaeria turcica, Cladosporium sphaerospermum, Chaetomium longiciliata, and Flavodon ambrosius were identified in 10 out of 18 khadi samples. Mycotoxins were detected using the Myco-10 Randox Evidence Investigator biochip kit and confirmed using a UPLC-ESI-MS/MS. Mycotoxins such as paxilline, ochratoxin A, ergot alkaloids, aflatoxin G1/G2, and zearalenone were detected using the Myco-10 Randox Evidence Investigator biochip kit. The Myco-10 results revealed that the mycotoxins in the khadi samples were lower than the regulatory limits set by FDA or European Commission. Confirmation of results using an UPLC-ESI-MS/MS system involved confirming selected mycotoxins (AFB1, DON. ZEA, FB1, FB2, FB3, NIV, and OTA) from selected khadi samples (Palapye 1, Palapye 2, Letlhakane 2, Maun 3, Mmashoro 3, and Tonota 3). The UPLC results demonstrated that the aforementioned mycotoxins in the selected khadi samples were below the detection thresholds. The study shows that while fungal isolates were present, there is no to minimal danger/risk of exposure to toxic mycotoxins after consumption of khadi. Towards commercialization endeavors, the production process would necessitate minimal mycotoxin monitoring and product preservation but no detoxifying steps.

Uropathogenic Escherichia coli (UPEC) is the most prevalent cause of urinary tract infections (UTIs). Biofilm formation and antibiotic resistance could be high among the causative agent. The purpose of this study was to determine antibiotic resistance, biofilm production, and biofilm-associated genes, bcsA and csgD, and sub-inhibitory hydrogen peroxide (H₂O₂) stimulation in UPEC for biofilm formation. A total of 71 UPEC were collected from a tertiary care hospital in Kathmandu and subjected to identify antibiotic susceptibility using Kirby-Bauer disk diffusion. The biofilm formation was assessed using microtiter culture plate method while pellicle formation was tested by a tube method. In representative 15 isolates based on biofilm-forming ability, bcsA and csgD were screened by conventional polymerase chain reaction, and treated with sub-lethal H₂O₂. The UPEC were found the most susceptible to meropenem (90.2%), and the least to ampicillin (11.3%) in vitro and 90.1% of them were multi-drug resistant (MDR). Most UPEC harbored biofilm-producing ability (97.2%), and could form pellicle at 37°C. Among representative 15 isolates, csgD was detected only among 10 isolates (66.67%) while bcsA gene was present in 13 isolates (86.67%). This study revealed that level of biofilm production elevated after sub-lethal H₂O₂ treatment (P = .041). These findings suggested that the pathogens are emerging as MDR. The biofilm production is high and the majority of selected strains contained bcsA and csgD genes. Pellicle formation test was suggestive to be an alternative qualitative method to screen biofilm production in UPEC. The sub-inhibitory concentration of H₂O₂ may contribute in increasing biofilm formation in UPEC.