International Journal of Microbiology最新文献

Cholera is a life-threatening diarrheal disease caused by Vibrio cholerae, with recurring outbreaks in Iraq, including the Kurdistan Region. Despite its endemic nature, outbreaks have primarily been reported by the health sector without comprehensive molecular epidemiological investigations. Limited studies have characterized outbreak dynamics, prevalence, and antimicrobial resistance, hindering effective public health interventions. This study aimed to analyze the prevalence, molecular characteristics, and antibiotic resistance of V. cholerae isolates from the 2023 outbreak in Sulaymaniyah, Kurdistan, Iraq. A total of 1200 diarrheic stool samples were collected from Shar Hospital between July and October 2023. Bacterial isolation was performed using microbiological methods and automated VITEK 2 analysis, followed by serological identification (O1 and O139 antisera) and 16S rRNA gene sequencing. Antibiotic susceptibility testing (AST) was conducted to assess resistance patterns. The outbreak prevalence was 0.015%, with the highest infection rate in August (0.009%). The overall infection rate was 28.91% (347/1200), with the most affected age groups being 19-33 years (27.66%) and 34-48 years (26.22%). Infection was more common in females (55.6%) than males (44.4%). Phylogenetic analysis revealed high genetic similarity to the V. cholerae Kuwait1 strain, suggesting potential introduction from southern Iraq, possibly due to an influx of tourists. Furthermore, antibiotic susceptibility testing revealed that all V. cholerae isolates were susceptible to most tested antibiotics; however, complete resistance (100%) was observed against amikacin, amoxicillin, amoxiclav, nalidixic acid, and trimethoprim, with partial resistance (30%) to tetracycline. Cholera remains a major public health concern in Kurdistan, particularly in Sulaymaniyah, due to recurrent outbreaks. Molecular techniques provided crucial insights into outbreak tracking and genetic relatedness, while AST profiling highlighted the urgent need for revised treatment guidelines. Strengthening water sanitation, continuous antimicrobial resistance monitoring, and targeted public health interventions are essential for preventing future outbreaks.

Bacterial proteases are valuable enzymes that accelerate the hydrolysis of peptide bonds within protein molecules. This study aimed to screen, identify, and optimize bacteria-producing protease from a tannery waste disposal site. Then, 36 morphologically distinct bacterial isolates were obtained from the Dire Tannery waste disposal site in Addis Ababa, Ethiopia. Among these isolates, DT-15 demonstrated the highest protease activity, with a clear zone of 19.00 ± 0.75 mm on skim milk agar, indicating its efficacy as a protease producer. Further morphological and molecular characterization of the most promising isolate was conducted. Based on its 16S rRNA sequence, the most effective isolate was identified as Bacillus pumilus. To enhance protease production, optimization experiments were carried out, resulting in an optimal enzyme activity of 506 ± 0.037 U/mL achieved after 60 h of incubation at 37°C and pH 7, using peptone and glucose as the nitrogen and carbon sources, respectively. Thus, the isolated bacterium has the potential to be utilized for various biotechnological applications, such as leather processing, detergent formulation, and food production. Further studies could focus on its applications in industrial processes.

The psychrophilic anaerobic digestion (PAD) system is a diverse and underexplored microbial ecosystem that typically harbors cold-adapted microorganisms with possible agronomic potential. The plant growth-promoting bacteria in the residue of PAD have the potential to enhance crop production, particularly during cold winter months. In this context, the characteristics of cultivable, cold-tolerant bacteria isolated from digestate obtained during PAD were investigated. Of the 20 isolates, 12 (60%) were able to solubilize phosphate from insoluble compounds at 15°C. Furthermore, nine (45%) and six (30%) isolates exhibited nitrogen fixation activity and produced indole acetic acid (IAA), respectively, while only two (10%) isolates were capable of producing siderophores. Hydrolytic enzyme production varied with cellulase production observed as a common trait since all isolates produced varying levels of cellulase ranging from 3.3 ± 0.5 to 15.3 ± 4 mm activity diameter. Isolates Comamonas sp._A3-1, Acinetobacter iwoffi_B5-1, and Pseudomonas sp._B5-5 displayed maximum cellulolytic activity with activity diameters of 13 ± 2, 13 ± 1.2, and 15.3 ± 4 mm, respectively. However, only two (10%) of the bacterial isolates produced protease with Pseudomonas sp._B5-5 demonstrating maximum proteolytic activity as depicted by an activity diameter of 11.3 ± 2.5 mm. Nucleotide sequence analysis of seven isolates, possessing multiple plant-beneficial traits, revealed their affiliation to three genera: Acinetobacter (57%), Comamonas (28.7%), and Pseudomonas (14%). Biolog Phenotype MicroArray plates revealed varied catabolic capability among bacterial strains, with isolate B5-5 demonstrating the highest metabolic diversity. The findings of this study revealed that cold-tolerant isolates from low-temperature AD possess promising plant growth-promoting characteristics, which indicates the potential of psychrophilic digestate for application in agriculture.

Atopic dermatitis (AD) is a chronic and inflammatory disease with an immunogenetic basis that can be triggered by extrinsic and intrinsic factors, including dysbiosis of the skin microbiota. The lipophilic Malassezia globosa is one of the dominant fungal species on the skin of AD patients. Malassezia and the host pathophysiologic mechanism underlying its role in exacerbating AD symptoms remain to be elucidated. This experiment established a fungal overgrowth model by topical administration suspension of M. globosa on BALB/c mice (M group) and MC903-induced AD model (AD+M group). Our results suggested that more severe AD-like lesions and higher dermatitis scoring were observed in the AD+M group compared with the AD group. The expression of TSLP mRNA in the tissue and serum IgE were highly increased in the AD group, while decreased significantly in the AD+M group. The expression levels of IL-17A and IL-22 in ear tissues and serum were significantly increased with M. globosa stimulation, especially in the AD+M group. Meanwhile, the percentage of Th17 and Th22 cells in the spleen were positively correlated with IL-17A and IL-22 levels in the serum. In contrast, IFN-γ and IL-4 production were significantly decreased in the AD+M group compared with the AD group. This study demonstrated that overgrowing M. globosa could aggravate AD symptoms and that IL-17A and IL-22 may be involved in the process. The promotion of IL-17A and IL-22 production induced by M. globosa may restrain the development of TSLP and inhibit the Th1/Th2 type skin inflammation.

Accumulation of solid waste is a major global challenge. The conventional waste disposal methods are often ineffective in mitigating solid waste pollution, highlighting the need for other sustainable alternatives. This study is aimed at isolating and identifying potential waste-degrading microorganisms from Mwakirunge dumpsite in Mombasa, Kenya. A total of 16 soil samples were collected using a randomized block design. The samples were inoculated in enriched basal media containing mixed municipal solid waste and incubated at 37°C for 21 days. Microbial identification was conducted using standard morphological, biochemical, and molecular approaches. DNA was extracted using organic isolation methods, and PCR amplification of the 16S rRNA gene for bacteria and the ITS gene for fungi was performed. Phylogenetic analysis grouped bacterial isolates into phylum Bacillota (Firmicutes), Pseudomonadota (Proteobacteria), and Actinomycetota (Actinobacteria) that included members of the genera bacilli, Pseudomonas, brevibacilli, Microbacterium, Ochrobactrum, Paenibacillus, Staphylococcus, Isoptericola, and Streptomyces. Fungal isolates belonged to the genus Aspergillus within the phylum Ascomycota. Three bacterial isolates B4S2 b (MZ571886), B3S1 (MZ571907), and B3S4 B (MZ571915) and one fungal isolate B2S2 a1 (MZ569413) had low sequence similarities with their closely known taxonomic relatives. The ability of the isolates to produce lipase, esterase, cellulase, amylase, and gelatinase enzymes was tested using the agar diffusion method. The results showed a significant level of enzyme production (p < 0.05). Bacillus cereus (MZ571899) exhibited the highest esterase activity; Streptomyces thermocarboxydus (MZ571882) exhibited the highest lipase activity, Bacillus subtilis (MZ571887) exhibited the highest amylase activity, and Bacillus licheniformis (MZ571888) exhibited the highest cellulase activity, while Pseudomonas stutzeri (MZ571900) exhibited the highest gelatinase activity. We recommend further studies to characterize the isolates with low sequence percentage similarities to establish their true identities. In addition, further enzymatic studies are required to quantify, characterize, and purify these enzymes for industrial applications.

Fowl cholera is a highly infectious bacterial disease in poultry production. It is caused by Pasteurella multocida (P. multocida) and leads to significant health risks and financial losses. Therefore, this study is aimed at isolating, molecularly detecting, and analyzing the antibiogram of P. multocida from breeder chickens in Gondar City. A cross-sectional study design with purposive sampling was employed to collect a total of 130 tracheal swab samples from breeder chickens showing clinical signs of fowl cholera between January 2023 and December 2023, based on case availability. Bacterial isolation was performed using bacteriological and biochemical tests. The isolated P. multocida was confirmed through conventional polymerase chain reaction (PCR) using a capsular serotype-specific primer (capA). The antibiogram assessment of P. multocida against 10 antimicrobial agents was conducted using the Kirby-Bauer disk diffusion method. Descriptive statistics were used to analyze the isolation rate of the bacterium. Of the 130 sampled swabs, 10 (7.69%) tested positive for P. multocida in the phenotypic assay, and 3 (30%) of those isolates were positive for the hyaD/hyaC virulence gene. The study found that all three isolates were 100% sensitive to penicillin, ampicillin, norfloxacin, and florfenicol, while showing 100% intermediate sensitivity to streptomycin and 66.7% intermediate sensitivity to gentamycin, amoxicillin, tetracycline, trimethoprim/sulphamethoxazole, and kanamycin. The study confirms that P. multocida, the causative agent of fowl cholera in breeder chickens, is circulating in the area and exhibits varying antimicrobial sensitivity profiles.

An examination of the fluctuating rates of the human papillomavirus (HPV) prevalence and the allocation of various genotypes could assist in the implementation of targeted strategies for the prevention and treatment of cervical cancer. The present study was aimed at evaluating the prevalence of HPV and genotype distribution among female populations in Zhangjiagang, Jiangsu Province, China. A total of 62,036 patients from the Affiliated Zhangjiagang Hospital of Soochow University provided clinical specimens between January 2022 and August 2023, and 12,144 women were infected with HPV, with an overall positive rate of 19.58%. The most prevalent HR-HPV types were HPV52 (4.14%), HPV16 (2.44%), HPV53 (2.37%), HPV58 (2.37%), and HPV56 (1.50%). In the low-risk group, the highest infection rate was HPV81 (1.76%). The prevalence of HPV infection showed a "U"-shaped curve. In addition to the adolescent group, other age groups are mainly single infection. And the gynecology clinic group had much higher rates of HPV positivity compared to the physical examination group (p < 0.001). Our study suggests that HPV screening and vaccination in young women are highly necessary, and 9-valent HPV vaccine is recommended for regular immunization in Zhangjiagang city.

Background: Infections of the tonsils are very frequent among 5-14-year-old children due to poor immunity establishments and inflammation within the tonsils because of insufficient penetration of antibiotics into the tonsillar core. This study was aimed at determining the bacterial profile, antibacterial susceptibility pattern, and associated factors among children with tonsillitis from selected health facilities in Hawassa town, Sidama, Ethiopia. Methods: An institution-based cross-sectional study was conducted using interviewer-administered, pretested questionnaires, and throat swab samples were collected from children with tonsillitis visiting selected health facilities in Hawassa town. A systematic random sampling technique was used to select the study units. Antimicrobial susceptibility testing was carried out by using the disc diffusion method according to criteria set by the Clinical Laboratory and Standard Institute 2020. Logistic regression evaluated factors related to the prevalence of culture-confirmed bacterial tonsillitis. Results: The overall prevalence of bacterial tonsillitis among children (408) with tonsillitis among selected health facilities was 276/408 (67.6%) (95% CI: 63.0%, 72.0%). The dominant bacterial isolate was Streptococcus pyogenes (70) (25.4%), followed by Streptococcus aureus (59) (21.4%), Staphylococcus epidermidis (56) (20.3%), Streptococcus pneumoniae (35) (12.7%), and Haemophilus influenzae (27) (9.8%). S. pyogenes was resistant to cephalexin (45.7%), penicillin (44.3%), and ceftriaxone (42.9%). Higher odds of having bacterial tonsillitis were observed for children from low monthly income families (adjusted odds ratio (AOR) 2.31, 95% CI: 1.15-4.63), those with enlarged or tender glands (AOR 2.47, 95% CI: 1.57-3.88), and those with a history of recurrent tonsillitis (AOR 1.85, 95% CI: 1.18, 2.92). Conclusions: Bacterial tonsillitis was prevalent in the study area. The isolates showed resistance to common antibiotics such as penicillin, chloramphenicol, clindamycin, ceftriaxone, and cephalexin. Therefore, culture and susceptibility tests are vital for appropriately managing bacterial tonsillitis.

Candida species, Trichomonas vaginalis, and bacteria are considered to be the main causes of vaginitis. This study investigated the prevalence of candidal, trichomonad, and bacterial vaginitis and factors related to infection in women. This cross-sectional study was conducted to investigate the relationship between different individual characteristics and common vaginal infections, namely, candidiasis, trichomoniasis, and bacterial vaginosis. The sample included all women referred to Allameh Bohlool Gonabadi Hospital women's clinic in Gonabad in 2021. After the patient's physical examination and questionnaire completion, samples were taken from the mucous secretions of the cervical vagina and the posterior fornix region using three sterile swabs. The first swab of secretions was placed on three glass slides for microscopic examination. At the same time, the second swab was transferred to the special Trichomonas culture medium (Dorset culture medium) available at the sampling site, observing sterile conditions. The third swab was placed in a test tube with a screw cap containing 5 cc of sterile physiological serum to be transferred to the laboratory. After adding two drops of potassium hydroxide (for elucidation), the first slide was examined under the microscope for the presence of Candida mycelia and buds. The second slide was used for warm staining to diagnose bacterial vaginosis. The third slide was used for Giemsa staining to detect Trichomonas. The swab in the screw-capped tube was stretched in Sabouraud Dextrose Agar (SDA) medium and kept in an incubator at 35° for 48 h to detect Candida. The prevalence of candidal, trichomonad, and bacterial vaginitis in the admitting women was 5%, 38.5%, and 5.8%, respectively. A significant relationship was found between the history of vaginal infection, trichomonad infection, and candidal infection (p = 0.03). Moreover, significant relationships were observed between bacterial infection and the husband's occupation (p = 0.002), methods of preventing pregnancy (p = 0.01), and menopause (p = 0.001). Vaginal infections are one of the common problems in women of all ages, and by knowing the factors that cause these infections, a big step can be taken to reduce the problem.

Modern agricultural practices rely heavily on fertilizers and pesticides to boost crop yields, essential for feeding the growing global population. However, their extensive use poses significant environmental risks. Chemical-based fertilizers and pesticides persist in ecosystems, potentially harming ecological stability. Wetland rice farming utilizing nitrogen-fixing cyanobacteria has emerged as an ecofriendly alternative, drawing attention due to its capacity to mitigate pesticide-related issues. Cyanobacteria, capable of fixing atmospheric nitrogen, thrive in low-nitrogen conditions and can aid plant growth. Some species can also biodegrade pesticides, offering a means to clean up contaminated environments. Researchers are exploring ways to leverage cyanobacteria's nitrogen fixation and biodegradation abilities for ecofriendly biofertilizers and environmental cleanup. This approach presents promise for sustainable agriculture and environmental preservation. The current study delves into multiple studies to investigate global pesticide usage levels, primary categorization, and persistence patterns. It also investigates cyanobacterial distribution and their interactions with pesticides in wetland rice ecosystems, aiming to enable their use in sustainable agriculture. Additionally, the review provides a thorough summary of the literature's findings about the potential of cyanobacteria in pesticide degradation.