International Journal of Microbiology

Background. Distinct bacterial strains may affect the prognosis of patients with chronic respiratory diseases. However, little is known about the clinical significance of respiratory bacteria in patients with chronic pulmonary aspergillosis (CPA), a progressive and debilitating disease caused by Aspergillus spp. Objectives. This study aimed to analyze data obtained from CPA patients and their sputum or bronchial washing samples and investigate the prevalence and composition of respiratory bacteria and clinical implications. Patients and Methods. We retrospectively reviewed the data of patients diagnosed with CPA between March 2019 and February 2023 in a tertiary referral hospital. We assessed the clinical characteristics and overall and pneumonia-specific survival rates of patients with CPA based on the presence of bacteria. Results and Conclusions. We included 142 patients with CPA. The most commonly identified bacteria were Klebsiella pneumoniae (22.5%), followed by Pseudomonas aeruginosa (21.8%) and Escherichia coli (4.2%). Patients with isolated bacteria had a higher prevalence of older age, female sex, diabetes, and a history of extrathoracic malignancy than those without isolated bacteria (, respectively). Furthermore, over a median follow-up of 11 (4–21) months, the pneumonia-specific mortality rate was 13.4% (19/142), which was higher in patients with isolated bacteria than in those without (, log-rank test). Particularly, patients with the presence of P. aeruginosa had a significantly higher mortality rate from pneumonia than those without the presence of P. aeruginosa (adjusted hazard ratio, 3.34; ). In conclusion, CPA patients with isolated bacteria, especially P. aeruginosa, showed higher mortality rates due to pneumonia. Performing tests to identify bacteria in the lower respiratory tract of patients with CPA may be helpful in predicting future prognosis. Further studies are required to validate these findings in diverse ethnic groups.

Bioactive peptides (BAPs) obtained from plants and microbes have been thoroughly explored and studied due to their prophylactic properties. The use of BAPs seems to be a promising substitute for several currently available antibiotics because of their antimicrobial properties against foodborne pathogens. BAPs have several other useful properties including antitumor, antihypertensive, antioxidant, antiobesity, and antidiabetic activities. Nowadays, scientists have attempted to recombinantly synthesize bioactive peptides to study their characteristics and potential uses, since BAPs are not found in large quantities in nature. Many pathogenic microorganisms including foodborne pathogens are becoming resistant to various antibiotics. To combat these pathogens, scientists are working to find novel, innovative, and safe antimicrobial agents. Plant- and microbe-based BAPs have demonstrated noteworthy antimicrobial activity against a wide range of pathogenic microorganisms, including foodborne pathogens. BAPs can kill pathogenic microorganisms by disrupting membrane integrity, inhibiting DNA and RNA synthesis, preventing protein synthesis, blocking protein activity, or interacting with certain intracellular targets. In addition, the positive effect of BAP consumption extends to gut microbiota modulation and affects the equilibrium of reactive oxygen species in the gut. This article discusses recombinant BAPs, BAPs generated from plants and microbes, and their antimicrobial applications and modes of action for controlling foodborne pathogens.

Hepatitis B virus (HBV) causes liver diseases (chronic hepatitis, cirrhosis, and hepatocellular carcinoma) and is a leading health problem worldwide. Sequencing of the whole HBV genome provides insight into the virus genotype, subgenotype, serotype, genetic variation, and viral drug resistance. To date, no study has been conducted on the whole genome sequence of HBV obtained from Iraqi patients. Therefore, this is the first study to sequence clinical samples from these patients. Viral genomic DNA was isolated and amplified using five primer sets to amplify five overlapping regions covering the entire HBV genome. The amplicons were sequenced, aligned to a reference sequence, annotated, and submitted to the National Center for Biotechnology Information GenBank database. Sequence analysis showed that the genome size of the tested viral samples was 3,182 bp and belonged to genotype D, subgenotype D1, and serotype ayw2. Missense mutations were found in the four regions (X, PreS1-S, PreC-C, and P) of the tested samples, leading to amino acid substitutions, which were 8.4%, 5.1%, 4.7%, and 4.6%, respectively. These mutations may cause severe liver diseases.

Poultry and poultry products are the common sources of Salmonella,which is one of the serious food-borne bacterial diseases in humans. Little is known about the status of Salmonella and their antimicrobial susceptibility in poultry farms in Addis Ababa. This study was conducted to estimate the prevalence and antimicrobial susceptibility of Salmonella isolates and to investigate possible risk factors for the occurrence of Salmonella in poultry farms in Addis Ababa. We recruited 58 poultry farms, from which 471 poultry-related samples and 44 stool samples from in-contact humans were collected. The isolates were tested for their susceptibility to 11 antimicrobials using the Kirby–Bauer disk diffusion assay. The farm-level prevalence of Salmonella was 36.2% and the sample-level prevalence was 6.4% for samples taken from poultry farms and 4.5% in human stool samples who have contact with poultry. On-farm waste disposal practices and chicken being purchased from different multiplication farms were significantly associated with Salmonella positivity of the farms (). Eleven (34.4%) Salmonella isolates were resistant to streptomycin, and nine (28.1%) were resistant to tetracycline. Thirteen (40.6%) Salmonella isolates were resistant to two or more antimicrobials tested in this study, whereas resistance to 3 or more antimicrobials was detected in seven (21.9%) isolates. In conclusion, a high prevalence of Salmonella and a high rate of resistance to multiple antimicrobials were detected in poultry farms in Addis Ababa. Hence, implementation of strong biosecurity measures and rational use of antimicrobials are recommended.

Ethiopia is a high-tuberculosis (TB) burden country with 157 new cases per 100,000 people, with 23,800 TB-related deaths in 2020. In Ethiopia, TB patients have different healthcare-seeking behaviors. They frequently visit spiritual places, such as holy water sites (HWSs), to seek treatment for their illness spiritually. This study examined the prevalence of pulmonary TB (PTB) and drug susceptibility profiles of Mycobacterium tuberculosis (MTB) isolates among spiritual HWS attendees in Northwest Ethiopia. A cross-sectional study was conducted from June 2019 to March 2020. Sputum samples were collected, processed, and cultured using Löwenstein–Jensen (LJ) culture medium. Second-generation line probe assays (LPAs), GenoType®MTBDRplus VER2.0 and GenoType®MTBDRsl VER2.0, were used to detect anti-TB drug-resistant isolates. STATA 17 was utilized to perform descriptive statistics, bivariate, and multivariate regression analyses. Of 560 PTB-symptomatic participants, 21.8% ((95% confidence interval (95 CI): 18.4–25.2%)) were culture-positive, resulting in a point prevalence of 1,183/100,000 attendees. Amongst HWS attendees, culture-positive TB occurred most commonly in persons 18–33 years of age (28.5% (95 CI 23.4–34.3%)). Other participant characteristics significantly associated with culture-positive PTB were as follows: rural residents (adjusted odds ratio (aOR) 2.65; 95 CI 1.38–5.10), married participants (aOR 2.43; 95 CI 1.28–4.63), family members >5 per household (aOR 1.84; 95 CI 1.04–3.24), and sharing living space (aOR 10.57; 95 CI 3.60–31.13). Also, among 438 participants followed for 12 months after showing negative TB culture results while at the HWS, 6.8% (95 CI 4.4–9.4%) developed or contracted culture-positive TB post-residency at the HWSs. Of the 122 tested isolates, 20 (16.4%) were isoniazid (INH) and/or rifampicin (RIF) resistant. Multidrug-resistant (MDR) TB was detected in 15 cases (12.3%), five of which were fluoroquinolones (FLQs) resistant. The findings from this study should raise a concern about HWSs as potential high-risk settings for TB transmission. It is recommended that appropriate control measures be instituted that include compulsory TB testing and tightened infection control at HWSs, where an increased risk exists for transmission of TB.

The exchange of technologies used in field cultivation for hydroponic systems can potentially increase plant development and grain production, requiring studies to verify the best management forms, such as growth-promoting bacteria and biostimulant compounds. With this in mind, the study aimed to evaluate the effect of the application of thiamine and niacin, alone and combined, to soybean plants in the absence and presence of inoculation with B. japonicum on the agronomic and physiological characteristics of the crop grown in an ebb and flow hydroponic system. Eight treatments were evaluated using t-test (LSD) and Tukey’s test, both at 5% probability (), in addition to Pearson correlation and canonical variables. The treatments consist of inoculation with B. japonicum at 1 mL 500 g⁻¹ seeds (with and without) and foliar application of four solutions (water, niacin (0.1 g·L⁻¹), thiamine (0.1 g·L⁻¹), and niacin + thiamine (0.05 g·L⁻¹ + 0.05 g·L⁻¹)). We found that inoculation significantly improved the parameters evaluated and resulted in a gain of approximately 84.8% in yield when compared by t-test (). In addition, the action of the vitamins was more significant when they were applied without the presence of B. japonicum, especially niacin, either alone or combined with thiamine, which increased yield parameters in this condition, identified when the Tukey’s test () was applied. We conclude that inoculation with Bradyrhizobium japonicum in soybean seeds grown in a hydroponic system significantly benefits the development and grain yield, mainly when combined with vitamin solutions. Niacin also has the potential to be used alone or combined with thiamine in noninoculated or inoculated hydroponic soybean crops, respectively.