فهرست مطالب

Microbiology - Volume:11 Issue:6, 2020
  • Volume:11 Issue:6, 2020
  • تاریخ انتشار: 1398/10/21
  • تعداد عناوین: 13
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  • Fatemehsadat Jamzivar, Masoomeh Shams Ghahfarokhi, Mansoor Khoramizadeh, Niloufar Yousefi, Mohammadhassan Gholami Shabani, Mehdi Razzaghi Abyaneh* Pages 448-459

    Over the past decades, the incidence of life-threatening fungal infections has increased dramatically in particular among patients with hampered immune function. Fungal infections cause around 1.5 million deaths annually, superior to malaria and tuberculosis. With respect to high toxicity, narrow spectrum of activity and drug resistance to current antifungals, there is an urgent need to discover novel leads from molecules of natural origin especially those derived from plants and microorganisms for antifungal drug discovery. Among antifungal drugs introduced into the clinic, those affecting ergosterol biosynthesis are still superior to other classes and the vital role of ergosterol in fungal growth and development. This review highlights current knowledge about available antifungal agents and further issues on antifungal drug discovery from compounds of natural origin which affect ergosterol biosynthesis. Special attention is made to the fungal sterol C24-methyltransferase (SMT), a crucial enzyme in ergosterol biosynthesis pathway as a novel target for rational drug design.

    Keywords: Ergosterol biosynthesis, Antifungal drug discovery, Natural compounds, Fungal infections
  • Rouhi Afkari, Mohammad Bokaeian, Soroosh Dabiri, Habib Ghaznavi, Mohsen Taheri, Fereshteh Heidari Tajabadi, Mohammad Mehdi Feizabadi* Pages 460-467
    Background and Objectives

    Oxalate degrading bacteria and herbal extracts are new strategy for reducing hyperoxaluria. In Iranian traditional medicine, Sankol oral drop is widely used as an antispasmodic drug to reduce stones from urinary tract. This study aimed to evaluate the synergistic effect of oxalate-degrading bacteria and Sankol oral drop in reducing urinary oxalate in rat model.

    Materials and Methods

    Several bacterial strains, including Lactobacillus (4), Bifidobacterium (2) and L. paracasei (2) (very strong in degrading oxalate in vitro) were used in this study. Male Wistar rats were divided into 6 groups (n = 6). The rats of Group I received normal diet and drinking water + 60% ethanol (positive group). Groups II (negative group), III, IV, V, and VI rats received diet containing ethylene glycol (3%) for 30 days. Groups III rats received Sankol with minimum concentration (7.5 ml/kg/b.w), Group IV rats received Sankol with maximum concentration (9 ml/kg/b.w), Group V rats received Sankol with minimum concentration + probiotic, and Group VI rats received Sankol with maximum concentration + probiotic for 30 days.

    Results

    Treatment with Sankol (maximum concentration) and oxalate-degrading probiotic bacteria significantly reduced urinary oxalate (P = .0001). At the end of treatment period, rats in groups II (negative control) showed a high score of CaOx crystal, while rats in VI groups did not show any CaOx crystal.

    Conclusion

    This is the first study on the simultaneous use of Sankol herbal drop and oxalate-degrading probiotic bacteria that showed a significant reduction in urinary oxalate.

    Keywords: Herbal medicine, Hyperoxaluria, Oxalate degrading bacteria, Probiotic bacteria, Sankol drop
  • Ibrahim Taher*, Abdulrahman Almaeen, Hassan Aljourfi, Eyad Bohassan, Ahmed Helmy, Eman El Masry, Baraka Saleh, Nawaf Aljaber Pages 468-477
    Background and Objectives

    Urinary tract infections are common health problem affecting millions worldwide. Antibiotic resistance among uropathogens (Ups) is prevalent in many countries. In the absence of any available data in the region, this hospital-based study investigated the pattern, frequency and susceptibility of Ups at Prince Mutaib Bin Abdulaziz Hospital, Aljouf Region, Saudi Arabia.

    Materials and Methods

    A retrospective assessment of UPs and their antibiotics susceptibility was conducted from January 2017 to December 2017 using the fully automated Vitek2 system (BioMérieux, France).

    Results

    Among the 415 uropathogens isolates, the most prevalent bacteria were Gram-negatives comprising 137 (51%) E. coli; 46 (17.2%) Klebsiella spp.; 30 (11.2%) Pseudomonas spp.; 25 (9.3%) Proteus spp.; 14 (5.2%) Acinetobacter baumanii and 16 (5.9%) others. On the other hand, Enterococcus spp. were predominant among Gram-positive isolates representing 54 (36.7%), 47 (32.0%) Staphylococcus spp., 22 (15.1%) Streptococcus spp., and 13 (8.8%) S. aureus, and 11 (7.5%) others. Gram-negative Ups showed multidrug resistance towards the majority of the tested antimicrobials (ampicillins, cephalosporins, fluoroquinolones, trimethoprim-sulfamethoxazole, fosfomycin, aztreonam, and nitrofurantoin). While high resistance patterns by Gram-positives was also seen against cephalosporins, penicillins, amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole, clindamycin, erythromycin and tetracycline.

    Conclusion

    The observed widespread multidrug resistance clearly warrant implementing stricter control measures, local guidelines of antimicrobials usage, and continuous epidemiological surveys at hospitals and communities.

    Keywords: Urinary tract infection, Gram-negative bacteria, Gram-positive bacteria, Antimicrobial susceptibility
  • Hossein Norouzian, Mohammad Katouli, Nader Shahrokhi, Shahram Sabeti, Mohammad Pooya*, Saeid Bouzari Pages 478-487
    Background and Objectives

    B2 and D have been mentioned as the most common phylogenetic groups among uropathogenic Escherichia coli. However, there is still controversy about the importance of these phylo-groups. This study was conducted to investigate the probable relation between these groups and antibiotic resistance patterns of E. coli isolates derived from urine and feces of the patients with acute or recurrent UTI.

    Materials and Methods

    10 isolates were recovered from urine and feces samples of patients with different phases of UTI in whom E. coli was causative pathogen. Biochemical fingerprinting was performed to classify the isolates and select their appropriate representatives. Phylogenetic grouping was performed using multiplex PCR, and antibiotic resistance was determined by disk diffusion method.

    Results

    Five-hundred-sixty E. coli isolates were derived from 56 UTI patients (27 acute, 29 recurrent). Among them, 261 isolates were selected using biochemical fingerprinting. All the isolates were sensitive to imipenem and nitrofurantoin. Compared to other phylo-groups, the isolates in group D showed considerably different frequencies in acute vs. recurrent phase of UTI, in urine vs. stool samples, in males vs. females, and in- vs. out-patients. They were more resistant to the antibiotics (except norfloxacin), and in contrast to others, this was seen more in acute UTI, especially in urine samples. Multi-drug resistance pattern was also meaningfully higher in group D.

    Conclusion

    Although phylo-groups B2 and D of E. coli bacteria are more responsible for UTI, group D isolates seem to be more resistant and probably more virulent, even than the ones from group B2.

    Keywords: Uropathogenic Escherichia coli, Acute urinary tract infection, Recurrent urinary tract infection, Antibiotic resistance, Phylogenetic groups
  • Appikatla Bhavana, Pilli Kumari, Nitin Mohan*, Vijayalakshmai Chandrasekhar, Payala Vijayalakshmi, Rongala Manasa Pages 488-495
    Background and Objectives

    The association between bacterial vaginosis and urinary tract infection (UTI) in pregnant women is at a greater risk comparatively than patients with bacterial vaginosis or UTI. Bacterial vaginosis and asymptomatic UTI both pose risk for mother and fetus. Early diagnosis and treatment can save the life of both. The present investigation was aimed to find out the magnitude of asymptomatic bacteriuria in pregnant women with noticeable bacterial vaginitis attending antenatal outpatient and inpatient of a tertiary care hospital and to identify the organisms causing it.

    Materials and Methods

    A total of 117 antenatal women from different age and parity groups with different gestational ages were included in the study. The samples were subjected to standard microbiological techniques for identification of microorganisms. While performing Per speculum examination, vaginal secretions were collected from the posterior fornix. Swabs from the posterior fornix were tested for pH using litmus paper. A wet mount and Gram smear was made and examined for the presence of bacteria, polymorphs and clue cells indicating bacterial vaginosis. Amsel’s criteria and Nugent scoring system were applied for diagnosis of bacterial vaginosis. Antibiotic susceptibility of the isolated bacteria was performed using Kirby-Bauer method.

    Results

    Bacterial vaginosis infection rate (62.3%) was common in the present study followed by asymptomatic UTI (n=60, 51%). It was also observed that asymptomatic urinary tract infection (UTI) with Bacterial vaginosis prevalent rate was 49 (41.8%) in the current study.

    Conclusion

    Bacterial vaginosis was more common than asymptomatic bacteriuria in pregnant women. It is recommended that antenatal health care facilities should incorporate screening of vaginitis among pregnant women to prevent the complications of pregnancy. And those women with Bacterial vaginosis should be screened for UTI. Proper use of antibiotics should be encouraged, abuse of antibiotics should be in check.

    Keywords: Antibiotic susceptibility pattern, Bacterial vaginosis, Pregnant women, Urinary tract infection Volume
  • Roghayeh Teimourpour, Behnam Babapour, Majid Esmaelizad, Mohsen Arzanlou, Hadi Peeri Doghaheh* Pages 496-501
    Background and Objectives

    Shigella is an etiological agent of shigellosis. Antibiotic therapy has a critical role in decreasing serious complications of shigellosis. The present study aimed to determine the multi-drug resistance strains and to detect fluoroquinolone related mutations.

    Materials and Methods

    In this descriptive, cross sectional study, a total of 113 Shigella isolates were collected from 1280 patients admitted to Bu-Ali hospital in Ardabil province during 2015-17. Antibiotic resistance pattern of isolates was evaluated using Kirby Bauer method and finally, the MICs of ciprofloxacin were determined. In order to determine any mutations in QRDR region, parC and gyrA genes of resistant strains were amplified and sequenced.

    Results

    Shigella spp. isolates were identified using ipaH amplification and rfc and wbgz genes were used for molecular detection of S. flexneri and S. soneii, respectively. Our results showed that the predominant species in Ardabil province was S. sonnei (69.91%). Most of isolates (82%) were resistant to trimethoprim/sulfamethoxazole (TMP/SMX); 51% were nalidixic acid resistant and 4.4% were floroquinolones resistant. All examined isolates were susceptible to imipenem (100%). Mutation in gyrA and parC genes were detected in all fluoroquinolone resistant isolates (5 isolates). Although, in this study the rate of resistance to ciprofloxacin was low, but in the lack of preventive strategy it will be a major challenge of public health in future.

    Conclusion

    This study provided information on the prevalence and antimicrobial susceptibility patterns of Shigella isolates in Ardabil province, Iran. Also this study showed a high-level of resistance to commonly used antibiotics among Shigella isolates.

    Keywords: Shigella, Fluoroquinolones, Nalidixic acid, Mutation, Gene
  • Niloofar Tafreshi, Laleh Babaeekhou*, Maryam Ghane Pages 502-509
    Background and Objectives

    Notwithstanding the increased prevalence of Acinetobacter baumannii drug-resistant isolates, treatment options are progressively limiting. This study aims to provide a recent report on antibiotic susceptibility in burn wound isolates of A. baumannii, and the importance of OXA beta-lactamases in carbapenem resistance.

    Materials and Methods

    The susceptibility levels to different antimicrobial categories were determined among 84 A. baumannii isolates from burn wound infection between 2016 and 2018. Multiplex PCR was used to detect OXA beta-lactamases genes, including blaOXA-51, blaOXA-23, blaOXA-24 and blaOXA-58. ISAba-1 association with blaOXA-51, blaOXA-23 and blaOXA-58 was detected by PCR mapping.

    Results

    All the isolates were determined as multidrug-resistant (MDR) and 69% as extensively drug-resistant (XDR). Different carbapenems MIC ranges (MIC50 and MIC90) were observed among the isolates harboring blaOXA-like genes and isolates with the OXA-24-like enzyme showed higher carbapenems MIC ranges. The prevalence of blaOXA-51-like, blaOXA-23-like, blaOXA-24-like and blaOXA-58-like were 100%, 53.57%, 41.66% and 30.95%, respectively. ISAba-1 insertion sequence was found to be upstream to blaOXA-23-like and blaOXA-58-like genes in 23 out of 45 (71.1%) blaOXA-23-like-positive and 4 out of 23 (15.3) blaOXA-58-like-positive isolates, respectively.

    Conclusion

    Resistance to carbapenems as the last resort for treatment of A. baumannii infections is growing. This study, for the first time in Iran, has observed the increased frequency of blaOXA-24-like and blaOXA-58-like genes and found an association between ISAba-1 and blaOXA-58-like gene, which signifies the possible risk of increased diversity in OXA beta-lactamases and growth in carbapenem resistance.

    Keywords: Acinetobacter baumannii, Antibiotic susceptibility, Carbapenem, OXA beta-lactamases
  • Sahar Hivary, Mahnaz Fatahinia, Marzieh Halvaeezadeh, Ali Zarei Mahmoudabadi* Pages 510-519
    Background and Objectives

    Black Aspergillus strains including, Aspergillus niger and A. tubingensis, are the most cause of otomycosis with worldwide distribution. Although, amphotericin B was a Gold standard for the treatment of invasive fungal infection for several decades, it gradually replaced by fluconazole and /or voriconazole. Moreover, luliconazole, appears to offer the best potential for in vitro activity against black Aspergillus strains. The aim of the present study was to compare the in vitro activity luliconazole, with commonly used antifungals against clinical and environmental strains of black Aspergillus.

    Materials and Methods

    Sixty seven (37 clinical and 30 environmental) strains of black Aspergillus were identified using morphological and molecular technique (β-Tubulin gene). In addition, antifungal susceptibility test was applied according to CLSI M38 A2. The results were reported as minimum inhibitory concentration (MIC) or minimum effective concentration (MEC) range, MIC50 or MEC50, MIC90 or MEC90 and MIC geometric (GM) or MECGM.

    Results

    Aspergillus niger was the common isolate followed by, A. tubingensis in both clinical and environmental strains. The lowest MIC range, MIC50, MIC90, and MICGM was attributed to luliconazole in clinical strains. The highest resistant rate was found in amphotericin B for both clinical (86.5%) and environmental (96.7%) strains whereas 54.1% of clinical and 30% of environmental isolates were resistant to caspofungin. Clinical strains of Aspergillus were more sensitive to voriconazole (86.7%) than environmental strains (70.3%). On the other hand, 83.8% of clinical and 70% of environmental isolates were resistant to posaconazole. 

    Conclusion

    Luliconazole versus amphotericin B, voriconazole, posaconazole and caspofungin is a potent antifungal for Aspergillus Nigri complex. The in vitro extremely antifungal efficacy against black Aspergillus strains of luliconazole, is different from those of other used antifungals.

    Keywords: Black Aspergillus strains, Luliconazole, Clinical, environmental isolates, Antifungal profile
  • Zahra Namvar, Abbas Akhavan Sepahy*, Robab Rafiei Tabatabaei, Sassan Rezaie Pages 520-526
    Background and Objectives

    Recent reports indicate high prevalence of fungal infections due to non-albicans Candida spp. which are present in various environments such as raw milk. The quality of milk for fungal normal flora was investigated in this study.

    Materials and Methods

    A total of 262 milk samples were collected directly from milk collection tanks indesignated dairy farms and cultured in SDA media. By further analysis of grown yeasts, 69 non-albicans Candida strains were identified. Antifungal susceptibility of the isolated species, were evaluated against amphotericin B, itraconazole, fluconazole and flucytosine. Fifty two non-albicans clinical samples isolated from human blood have been evaluated along.

    Results

    Antifungal susceptibility evaluation in non-albicans strains isolated from milk revealed Candida glabrata and Candida tropicalis to be 100% sensitive to flucytosine and fluconazole. Candida krusei showed 94% and 80% sensitivity to flucytosine and fluconazole respectively. Candida parapsilosis indicated 72.72% sensitivity to fluconazole.

    Conclusion

    Evaluation of non-albicans Candida species in raw milk and antifungal susceptibility patterns of these isolatescompare with non-albicansisolates from human blood, may help physicians to choose an appropriate medication for diseases needing long-term treatment, especially for diseases caused by local strains.

    Keywords: Candida parapsilosis, Candida glabrata, Candida krusei, Candida tropicalis, Antifungal, Raw milk
  • Ghita Benjelloun Touimi, Laila Bennani, Sanae Berrada, Moussa Benboubker, Bahia Bennani* Pages 527-534
    Background and Objectives

    Food in healthcare settings are complementary to medical treatment, hence it should be produced in good sanitary conditions. In fact, hospitalized and immune-compromised patients are more likely to have foodborne infections than the rest of the community. The aim of our study is to evaluate the microbiological quality of food contact surfaces in a hospital kitchen in Morocco.

    Materials and Methods

    A total of 238 samples was collected from kitchen surfaces and analyzed for total aerobic mesophilic bacteria (AMC), Enterobacteriaceae and Staphylococcus aureus count and the presence of Salmonella spp., Pseudomonas spp. and Listeria monocytogenes.

    Results

    The bacteriological analysis shows that the highest rates of compliance with good hygienic conditions were obtained in baking worktops (77%) and serving meal worktops (50%) and the vegetables cutting boards (45.83%). In contrary, some surfaces show a low level of compliance, such as the raw meat cutting boards (96%). The isolated bacteria were S. aureus, coagulase-negative staphylococci, Escherichia coli, Serratia marcescens, Serratia odorifera, Raoultela ornithiaolytica and Pseudomonas aeroguinosa.

    Conclusion

    The actual results indicate that the high levels of bacterial counts on kitchen surfaces, presents an evident need to improve the hygienic process and adopt an HACCP system in this facility.

    Keywords: Hospital infection, Food contact surfaces, Hygiene, Food safety, Microbial profile
  • Najmeh Dalvand, Azadeh Dalvand, Zohreh Sharifi*, Seyed Masoud Hosseini Pages 535-540
    Background and Objectives

    HEV infection is predominantly spread via the fecal-oral route; however, due to the presence of HEV RNA in the serum of healthy blood donors, there is a possibility of the transmissibility of HEV infection through blood. Multi-transfused thalassemia patients are one of the high risk groups for blood borne viruses. In this study, we evaluated the prevalence of HEV antibodies and HEV-RNA in thalassemia patients with HCV infection.

    Materials and Methods

    120 anti-HCV positive thalassemia patient serum samples from Tehran province during April-June 2019 were assessed for the presence of total anti-HEV antibodies using of HEV Ab ELISA kit. All serum samples were assayed by Nested RT-PCR to detect HEV-RNA.

    Results

    The results of ELISA test showed that 2 out of 120 (1.67%) samples were positive for anti-HEV Ab. There was no statistically significant difference between anti-HEV antibody prevalence rate and sex, age and other risk factors. None of 120 (0.00%) samples were positive for HEV-RNA by Nested RT-PCR.

    Conclusion

    Seroprevalence of HEV in our study group was 1.67% which is less than HEV seroprevalence rate in Iranian general population. Therefore, it can be conclude that transmission of HEV infection via blood transfusion seems to be uncommon in Iran and the fecal-oral route can be the predominant mode of transmission in Iran; however, more studies are required to confirm this issue.

    Keywords: Hepatitis E virus, Thalassemia, Hepatitis C virus, Genotype
  • RETRACTED ARTICLE: The effect of a single-strain probiotic administration in the treatment of thermal burns patients
    David Perdanakusuma, Lynda Hariani, Nur Nasser, Robertus Datusanantyo Page 541
    Background and Objectives

    Between 2007 and 2011, the mortality rate for burns patients at Dr. Soetomo General Hospital, Surabaya, Indonesia was 14.1% and 60% were suspected to be sepsis-related. Immunosuppression, gut barrier disruption, and intestinal hypomotility cause bacterial and bacterial product translocation. Probiotics improve the intestinal microbiome and eventually reduce bacterial translocation, and an increased secretory immunoglobulin A (SIgA) secretion post-administration of a multi-species probiotic has been observed. We aimed to determine whether a single-strain probiotic administration could show strengthened intestinal immunity, through an increase in SIgA levels, as with multi-strain probiotics.

    Materials and Methods

    Sixteen burns patients from our hospital Burns Centre were randomized into three treatment groups, and the patients were administered either a placebo, a Lactobacillus reuteri protectis probiotic, or a Bifidobacterium infantis 35624 probiotic for 14 consecutive days. The SIgA levels were analyzed using ELISA pre- and post-treatment.

    Results

    The post-treatment SIgAlevelsin the placebo, Lactobacillusreuteri protectis probiotic, and Bifidobacterium infantis 35624 probiotic groups were 222.56±74.22 mg/dL, 223.92±68.89 mg/dL, and 332.38±64.27 mg/dL, respectively. Decreased SIgA levels were observed in the placebo (7.19±15.87) and in the Lactobacillus reuteri protectis probiotic (1.9920±14.76) groups, whereas an increase was seen in the SIgA level in the Bifidobacterium infantis 35624 probiotic group (58.26±77.41).

    Conclusion

    The Bifidobacterium infantis 35624 single-strain probiotic is generally superior to Lactobacillus reuteri protectis in altering intestinal immunity; however, this finding was not statistically significant. A multi-strain probiotic supplement is recommended for burns patients.

  • Seyyed Jafar Motahari, Parvaneh Afshar, Maryam Ghasemi, Lale Vahedi Larijani*, Somayeh Sheidaei Pages 542-545

    Primary tonsillar tuberculosis is an uncommon entity and a diagnostic challenge. Misdiagnosis can be prevented with early professional para-clinical finding. The true diagnosis is often delayed and infection management depends on recognizing disease patterns and early laboratory documentation.This rare clinical caseation granuloma with positive clinical symptoms, negative results of radiology/laboratory and alone based on histopathological finding without any Mycobacterium particle indicates the role of an accurate laboratory/pathology finding for urgent medical intervention treatment and lifesaving of patients,particularly in immunocompromised group.

    Keywords: Tonsil, Tuberculosis, Mycobacterium tuberculosis, Lymphadenopathy