فهرست مطالب

Iranian Journal of Microbiology
Volume:14 Issue: 3, Jun 2022

  • تاریخ انتشار: 1401/03/30
  • تعداد عناوین: 21
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  • Kamran Lankarani, Maryam Akbari*, Reza Tabrizi, Mohebat Vali, Eghbal Sekhavati, Seyed Taghi Heydari, Hossein Khodadadi, Fariba Ahmadizar Pages 276-284
    Background and Objectives

    Candida auris (C. auris) is the first fungal pathogen considered a global health threat. Because, C. auris is associated with multidrug resistance and associated diseases such as diabetes, sepsis, lung and kidney disease. This study investigated the prevalence and mortality of C. auris infection during Covid-19 pandemic.

    Materials and Methods

    Databases were searched for peer-reviewed articles published in the English language up to Jan 18, 2022. Heterogeneity across studies was evaluated using Cochrane’s Q test and the I2 index. The pooled point prevalences and their corresponding 95% confidence intervals (CIs) were estimated usingthe random-effects model.

    Results

    In our meta-analysis, 11 eligible articles were included. The total pooled prevalence estimation of C. auris infection among COVID-19 patients was 13% (95% CI: 8%, 19%). The estimated pooled mortality rate of C. auris infection was 37% (95% CI: 15%, 61%). In terms of specific conditions, the pooled risk of mortality was higher in people with diabetes 65% (95% CI: 0.45%, 83%), in cases with >21 days admission inintensive care unit (ICU) 44% (95% CI: 21%, 0.68%), and after receiving steroids 43% (95% CI: 18%, 69%).

    Conclusion

    Our study highlights the high prevalence rate of C. auris infection, particularly among people with a history of metabolic disorders.

    Keywords: Candida auris infection, COVID-19, Disease outbreaks, Meta-analysis
  • Khalil Ansarin, Leyla Sahebi * Pages 285-290
    Background and Objectives

    Drug-resistant tuberculosis (Tb) is a major public health issue across the world. Therefore, it is crucial to determine its pattern in different regions of the world. The aim of this study was to review the prevalence of drug resistant TB in the west and northwest of Iran.

    Materials and Methods

    A systematic literature search was performed to identify studies (2010 to 2021) in Google Scholar, PubMed, Thomson Reuters, Scientific Information Database (SID), Cochrane Library, and Medical Library (MedLib) databases. The patterns of any drug-resistant Mycobacterium tuberculosis (MTB); resistance to isoniazid (INH), rifampicin (RMP), streptomycin (SMP), ethambutol (EMB), and multiple drug resistance (MDR) were reviewed in tuberculosis in the west and northwest of Iran.

    Results

    In this review, 7 studies met the eligibility criteria for a meta-analysis. The pooled proportion of any drug resistant TB was 13% (CI 95%: 9.0, 17.0) (43.0% in re-treatment group). The pooled prevalence of any drug resistant TB was more than 1.5 times higher in men compared to women (15% vs. 9.0%). The pooled prevalence (%) of resistance to INH, RMP, SMP, EMB and MDR-TB was 11.0%, 12.0%, 13.0%, 6.0%, and 6.0%, respectively. Kermanshah Province (a province in the west of Iran) showed a high prevalence of any type of drug resistance and MDR-TB (15.9% and 20.0%, respectively).

    Conclusion

    It seems that the western provinces of Iran have a different pattern of drug resistance compared to the northwestern provinces. Considering the extent of Iran and the neighboring countries, it is recommended that the pattern of tuberculosis drug resistance be reviewed separately in different provinces or regions of Iran. Drug resistance in the re-treatment group was more than three times that of all patients with TB drug resistance. The burden of drug resistance reduces significantly with better control and management of TB drug treatment and preventing re-infection.

    Keywords: Drug resistance, Tuberculosis, Meta-analysis
  • Maria Zapata-Cardona, Lizdany Flórez-Álvarez, Diana Gómez-Gallego, María Moncada-Díaz, Juan Hernandez, Francisco Díaz, María Rugeles, Wbeimar Aguilar-Jiménez, Wildeman Zapata* Pages 291-299
    Background and Objectives

    SARS-CoV-2 variants of concern (VOC) and interest (VOI) pose a significant threat to public health because the rapid change in the SARS-CoV-2 genome can alter viral phenotypes such as virulence, transmissibility and the ability to evade the host response. Hence, SARS-CoV-2 quantification techniques are essential for timely diagnosis and follow-up. Besides, they are vital to understanding viral pathogenesis, antiviral evaluation, and vaccine development.

    Materials and Methods

    Five isolates of SARS-CoV-2: D614G strain (B.1), three VOC (Alpha, Gamma and Delta), and one VOI (Mu) were used to compare three techniques for viral quantification, plaque assay, median tissue culture infectious dose (TCID50) and real-time RT-PCR.

    Results

    Plaque assay showed viral titers between 0.15 ± 0.01×107 and 1.95 ± 0.09×107 PFU/mL while viral titer by TCID50 assay was between 0.71 ± 0.01×106 to 4.94 ± 0.80×106 TCID50/mL for the five SARS-CoV-2 isolates. The PFU/mL titer obtained by plaque and the calculated from TCID50 assays differed by 0.61 log10, 0.59 log10, 0.59 log10 and 0.96 log10 for Alfa, Gamma, Delta, and Mu variants (p≤0.0007), respectively. No differences were observed for the D614G strain. Real-time PCR assay exhibited titers ranging from 0.39 ± 0.001×108 to 3.38 ± 0.04×108 RNA copies/µL for all variants. The relation between PFU/mL and RNA copies/mL was 1:29800 for D614G strain, 1:11700 for Alpha, 1:8930 for Gamma, 1:12500 for Delta, and 1:2950 for Mu.

    Conclusion

    TCID50 assay was comparable to plaque assay for D614G but not for others SARS-CoV-2 variants. Our data demonstrated a correlation among PFU/mL and E gene RNA copies/µL, units of measure commonly used to quantify the viral load in diagnostic and research fields. The results suggest that the proportion of infectious virions in vitro changes depending on the SARS-CoV-2 variant, being Mu, the variant reaching a higher viral titer with fewer viral copies.

    Keywords: SARS-CoV-2 variants, Virus titer, Real-time reverse transcription-polymerase chain reaction, Plaque assay, Median tissue culture infectious dose assay
  • Vivi Setiawaty*, Dini Darmawati, Arie Nugraha, Pancrasia Hendrati Pages 300-304
    Background and Objectives

    Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is commonly detected in pneumonia patients who travel from the Middle East regions. Besides MERS-CoV, many other pathogenic agents cause pneumonia. Detection of such organisms must be done swiftly, especially in case of the negative MERS-CoV samples. The aim of this study was to identify the pathogenic agents that might account for bacterial pneumonia, from Hajj and Umrah pneumonia cases.

    Materials and Methods

    We conducted a cross-sectional study, 38 pneumonia clinical samples from suffering of Hajj and Umrah in 2017 with negative MERS-CoV were selected. The laboratory testing was done at National Reference Laboratory in Jakarta and performed by multiplex real-time PCR using a FTD respiratory pathogens.

    Results

    Haemophilus influenzae (26.4%) was the most frequent bacteria detected. Other causative agents of bacterial pneumonia identified were Moraxella catarrhalis (20.8%), Klebsiella pneumoniae (13.2%), Streptococcus pneumoniae (9.4%), and Staphylococcus aureus (5.7%). From 38 samples showed that 25 (65.79%) samples were positive with bacteria, including five samples with coinfection. The coinfection were combinations among S. aureus and S. pneumoniae (1/20), S. pneumoniae and K. pneumoniae (1/20), S. pneumoniae and M. catarrhalis (2/20), S. pneumoniae and H. influenzae (2/20), K. pneumoniae and H. influenzae (5/20), and M. catarrhalis and H. influenzae (5/20).

    Conclusion

    Haemophilus influenzae is the most recurrent bacteria to be identified in samples of pneumonia of hajj and umrah cases.

    Keywords: Pneumonia, Multiplex real-time polymerase chain reaction, Bacteria, Hajj, umrah
  • Samaneh Bourbour, Reza Beigverdi, Maryam Beheshti, Fereshteh Jabalameli, Mohammad Emaneini * Pages 305-312
    Background and Objectives

    Aminoglycosides have been widely used for treating severe staphylococcal infections. Production aminoglycoside modifying enzymes (AMEs) is the main mechanism of resistance to this antibiotic. The aim of this study was to determine the prevalence of AME genes and molecular characterization of aminoglycoside-resistant Staphylococcus aureus and Staphylococcus epidermidis strains isolated from clinical specimens in Iran.

    Materials and Methods

    A total of 42 clinical isolates of Gram-positive cocci (20 S. aureus and 22 S. epidermidis) with resistance to gentamicin were tested for antimicrobial resistance and differentiated by multilocus sequence typing (MLST).

    Results

    All 42 isolates were resistant to methicillin, kanamycin,and most of them were also resistant to amikacin (98%), tobramycin (98%) and netilmycin (78.5%). Overall, aac(6’)-Ie-aph(2’’)-Ia was the dominant AME gene found in 100% of isolates, followed by aph(3')IIIa found in 90% of isolates. MLST classified S. aureus and S. epidermidis into 5 and 9 distinct sequence types (ST), respectively. The majority of the strains belonged to ST239 (50%) for S. aureus and ST2 (36%) for S. epidermidis.

    Conclusion

    The resistance to aminoglycosides was mainly due to the presence of the aac(6’)-Ie-aph(2’’)-Ia and aph(3')IIIa genes as well as the ST239 for S. aureus and ST2 for S. epidermidis have become the predominant clones in the selected university hospital of Tehran, Iran. Thus, it is critical that clinicians and healthcare workers are aware of the population of S. aureus and S. epidermidis present in order to make decisions for appropriate treatment and infection control practices.

    Keywords: Aminoglycosides, Aminoglycoside modifying enzymes, Staphylococcus aureus, Staphylococcus epidermidis, Multilocus sequence typing
  • Narjes Feizabadi, Javad Sarrafzadeh, Mojtaba Fathali, Behnoosh Vasaghi-Gharamaleki, Mahdi Dadgoo, Jalil Kardan-Yamchi, Hossein Kazemian, Sonia Hesam-Shariati, Mohammad Mehdi Feizabadi * Pages 313-318
    Background and Objectives

    Bacterial involvement in chronic rhinosinusitis (CRS) condition made it difficult to treat using available antibiotic therapy. Therapeutic ultrasound was investigated here to evaluate bacterial diversity and quantity before and after continuous/pulsed ultrasound strategy compared to control patients.

    Materials and Methods

    Totally, 34 CRS patients were studied in three groups, including continuous ultrasound, pulsed ultrasound and control. Bacterial culture and identification were done before and after treatment. Computed tomography scan (CT scan) and questionnaire scores were recorded two times before and after intervention.

    Results

    The most prevalent bacterial isolates were non-hemolytic Streptococci (34 patients), coagulase-negative Staphylococcus (33 patients), Gram-negative cocci (26 patients), Staphylococcus aureus (19 patients), Streptococcus pneumoniae (five patients) and Streptococcus pyogenes (five patients). Both continuous and pulsed ultrasound could significantly reduce the quantity of bacterial isolates after treatment. CT scan and questionnaire results support the effectiveness of therapeutic ultrasound.

    Conclusion

    The quantity of clinically important bacteria was significantly reduced using ultrasound treatment and recovery of patients was supported by CT scan and questionnaire scores. Alternative therapeutic ultrasound could be an effective procedure in CRS patients.

    Keywords: Rhinosinusitis, Ultrasound therapy, Bacterial infection, Treatment, Computed tomography scan
  • Safar Farajnia, Fariba Lotfi, Alireza Dehnad, Maryam Shojaie, Roya Raisi, Leila Rahbarnia *, Ahad Bazmani, Behrooz Naghili, Samaneh Shiry Pages 319-327
    Background and Objectives

    The objective of this study was to determine molecular characterization and genetic diversity of colistin-resistant A. baumannii clinical isolates in Intensive Care Unit hospitalized patients.

    Materials and Methods

    A total of 127 A. baumannii clinical isolates were evaluated for antimicrobial susceptibility. PCR reaction and sequencing were performed for the detection of mutations in pmrAB and lpx ACD genes.

    Results

    Based on antimicrobial susceptibility testing, 40.94% and 33.85% of the isolates were MDR and XDR respectively whereas 3.93% of them were found to be PDR. Results of agar dilution MIC and E-test indicated that 76% of the isolates were sensitive to colistin. All of the isolates were positive for blaOXA-51 and 50% of them were positive for both blaOXA-23-like and blaOXA-143-like genes while only 25% of the isolates were positive for blaOXA-72. None of them were positive for the blaOXA-58-like gene. There is no mutation in pmrA. The V162A substitution for pmrB gene was repeated in two isolates, and E394 D and Y292H substitutions in lpxA were observed in two isolates; also, C120R and F165L substitutions in lpxC gene was repeated in two isolates. Analysis of phylogenetic tree based on alterations in lpxACD and pmrB genes indicated the appearance of new isolates compared to the reference strain ATCC17978 A. baumannii isolates.

    Conclusion

    The present study indicated the prevalence of MDR and XDR A. baumannii isolates and the emergence of PDR isolates in the northwest portion of Iran. The appearance of colistin-resistant isolates with new mutations in pmrB, lpxACD genes indicates new resistance mechanisms.

    Keywords: : Acinetobacter baumannii, Beta-lactamase OXA-23, Beta-lactamase OXA-143, OXA-72 carbapenemase, Beta-lactamase OXA-58, Colistin
  • Melike Yaşar-Duman*, Feriha Çilli, Yamaç Tekintaş, Furkan Polat, Mine Hoşgör-Limoncu Pages 328-333
    Background and Objectives

    RESİST-4 O.K.N.V. assay is a lateral immunochromatocraphic test for the identification of oxacillinase (OXA)-48-like, Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), and Verona integron-encoded metallo-β-lactamase (VIM) producing strains. It was aimed to evaluate the performance of the RESIST-4 O.K.N.V. test and to compare it with the reference method polymerase chain reaction (PCR). Also, the objective was to determine the distribution of carbapenemase types of CRE strains isolated in our hospital.

    Materials and Methods

    Between January 2016-October 2019, 187 strains isolated from clinical samples were included in this study. Bacterial identification was done using MALDI-TOF MS. Antibiotic susceptibility tests were studied with the VITEK-2 automated system. Meropenem minimum inhibitory concentrations (MICs) were determined by the gradient test. All strains were studied with the RESIST-4 O.K.N.V. test and then the strains were selected for the PCR test. blaOXA-48, blaNDM, blaKPC, and blaVIM were investigated with PCR. K. pneumoniae NCTC® 13438 (KWIKSTIKTM, Microbiologics®,USA) was used as the positive control, E. coli ATTC® 25922 TM (Microbiologics®,USA) and three carbapenem-sensitive clinical isolates were also used as the negative control.

    Results

    Meropenem MIC50 and MIC90 values were determined to be >32 mg/L. With PCR blaOXA-48, blaNDM, blaKPC, and blaVIM were detected in 79, 63, 20, and 4 strains, respectively. blaOXA-48 and blaNDM were found together in 51 of the isolates. blaOXA-48, blaNDM, blaKPC, and blaVIM were not detected in two strains with carbapenem resistance in susceptibility tests. The sensitivity of the immunochromatographic test was 100% for OXA-48, KPC, and VIM but 84.1% for NDM. Specificity was determined as 100% for OXA-48, NDM, KPC, and VIM.

    Conclusion

    RESIST-4 O.K.N.V. test showed high sensitivity and specificity in detecting OXA-48, KPC, NDM, and VIM type carbapenemases. However, it should be kept in mind that there may be false-negative results related to NDM.

    Keywords: Carbapenemases, Immunochromatographic test, Oxacillinase-48, Klebsiella pneumoniae
  • Chikaodili Nwokolo, Malachy Ugwu *, Chika Ejikeugwu, Ifeanyichukwu Iroha, Charles Esimone Pages 334-340
    Background and Objectives

    This study investigated the incidence and antibiotic susceptibility profile of extended spectrum β-lactamase (ESBL) producing uropathogenic Escherichia coli recovered from HIV/AIDS patients in Awka metropolis, Nigeria.

    Materials and Methods

    A total of 363 urine samples were bacteriologically analyzed for the isolation of E. coli isolates which were further characterized using standard microbiology techniques. The isolated uropathogenic E. coli was tested for susceptibility to a range of clinically important antibiotics using the modified disk diffusion technique. All E. coli isolates were phenotypically screened for ESBL production using the combined disk technique, and strains which were positive were further confirmed for the presence of ESBL genes using PCR technique.

    Results

    A total 160 (44.1%) non-duplicate isolates were bacteriologically confirmed to be uropathogenic E. coli (UPEC). The E. coli isolates showed reduced susceptibility to important antibiotics including ceftazidime (76.88%), cefuroxime (77.5%), cefixime (61.88%), amoxicillin-clavulanic (32.5%) and ciprofloxacin (34.38%). Twenty-seven of the UPEC isolates were phenotypically confirmed to be ESBL producers. PCR test confirmed some important genes mediating ESBL production in Gram negative bacteria including blaTEM (5.0%) and blaCTX-M-15 (6.9%) genes.

    Conclusion

    We report a high prevalence of ESBL producers among HIV/AIDS patients in Awka, Nigeria. This result is important as antibiotic resistance (ABR) particularly those mediated by multidrug resistant bacteria as reported in this current study could complicate treatment outcome, worsen the individual’s health, and even increase cost of treatment and hospitalization. It is therefore important to lookout for ESBL positive UPEC amongst HIV/AIDS patients in Nigeria.

    Keywords: : HIV, Drug resistance, Uropathogenic Escherichia coli, Antimicrobial resistance, Extended-spectrum β-lactamase
  • Asmaa Mohsin *, Ali Alsakini, Munim Ali Pages 341-350
    Background and Objectives

    Urinary tract infections are one of the most commonly associated human infectious diseases caused by the bacteria Escherichia coli. Escherichia coli is described as having a large number of virulence genes that enable drug resistance, which is a cause for great concern. Monitoring of antimicrobial susceptibility is critical to determining the scope of the problem and selecting appropriate antimicrobial drugs. The current study aimed to identify the distribution of uropathogenic E. coli (UPEC) based on genetic profiles and to determine resistance patterns among isolates.

    Materials and Methods

    This study employed biological correlations to study the patterns of antibiotic resistance and the distribution of phylogenetic groups of 118 isolates of E. coli and the relationship between them, which were isolated from three hospitals in Baghdad, Iraq.

    Results

    The results of phylogenetic analysis showed that phylogroup F was the most common group among E. coli isolates (37.3%), followed by phylogroups C (20.3%), B2 (15.3%), E (14.4%), UP (4.2%), A and D (3.4%), and B1 (1.7%). The majority of antibiotic resistance patterns were related to penicillin groups (80.5%) and the least to the sulfonamide groups (67.0%). 51.7%, 42.4%, and 1.7% of isolates were Extensive Drug Resistance (XDR), Multi-Drug Resistance (MDR), and Pan Drug Resistance (PDR), respectively. Antibiotic resistance was most commonly detected in group F (35.6%).

    Conclusion

    Our observations revealed that the dominant phylogroup F had the highest prevalence of multi-drug resistance and extensive drug resistance among E. coli isolates. The newly identified phylogroups C, E, and F account for about 72.0% of the E. coli isolates. Such investigations should be conducted in other localities as well, in order to gain a better understanding of the pattern of antibiotic resistance patterns and the frequency of distinct phylogenetic groups.

    Keywords: Escherichia coli, Urinary tract infection, Drug resistance, Phylogenetic F, Phylogenetic group
  • Omowumi Akinola*, Faustina Onyeaghasiri, Olayinka Oluranti, Olayinka Elutade Pages 351-361
    Background and Objectives

    Unsafe water supplies are of public health concern, especially in developing countries. This article aims to investigate the microbiological quality of water from eight Wells in Iwo and to explore for the extended-spectrum β-lactamase (ESBL) and carbapenemase genes contained in isolated enteric bacteria from in the water samples.

    Materials and Methods

    Bacterial isolation and identification were done using standard conventional methods. Antibiotic susceptibility testing was conducted using the Kirby–Bauer method. Ten phenotypically carbapenem-resistant isolates were further subjected to genotypic analysis (PCR amplification) for the detection of ESBL and carbapenemase gene.

    Results

    A total of 148 Enterobacteriaceae isolates belonging to seven (7) genera were isolated and identified which included E. coli, Enterobacter spp., Klebsiella spp., Salmonella, Citrobacter sp, Proteus, and Shigella. Results showed that 55% of isolates were resistant to tetracycline, 28% to cefepime, the least resistance was shown in moxifloxacin and gentamicin which had 6% and 9%, respectively, of the total isolates. For the two carbapenems used, results showed meropenem and imipenem had resistant values of 14% each, respectively. Two isolates carried the blaCTX-M gene while the carbapenemase gene (blaKPC, blaNDM, and blaOXA) was not detected in all the ten isolates.

    Conclusion

    There was also negative chromosomal detection of carbapenemase in MDR isolates from well waters in Iwo town. Consequently, resistance to carbapenem antibiotics in these isolates may not be mediated by carbapenemase but by the production of extended-spectrum β-lactamases and through other mechanisms of resistance.

    Keywords: Antibiotic resistance, Carbapenem, Enterobacteriaceae, Extended-spectrum β-lactamases, Nigeria, Water quality
  • Atena Sadeghi, Leila Ganji, Fereshteh Fani, Gholamreza Pouladfar, Parisa Eslami, Fatemeh Doregiraee, Parviz Owlia*, Masoud Alebouyeh Pages 362-372
    Background and Objectives

    Source tracking of antimicrobial resistance in Campylobacter is useful for control measures. In this study, Campylobacter-associated diarrhea and homology in antimicrobial resistance of humans and poultry meat isolates were investigated.

    Materials and Methods

    A total of 400 stools of patients and 100 poultry meat samples were analyzed. Susceptibility of the isolates was detected by disk diffusion, Etest, and agar dilution methods. Mismatch amplification mutation assay was used for the detection of mutations in the gyrA quinolone resistance determining region (QRDR).

    Results

    Campylobacter spp., including C. jejuni, C. coli, and C. lari, were detected in 35% of the chicken meat and 6.75% of the stool samples, respectively. The QRDR mutation was detected in most of the stool and chicken meat samples. Although the frequency of resistance to tetracycline (53.5% and 62.8%), erythromycin (39.2% and 37.1%), and gentamicin (32.1% and 31.4%) was relatively similar, higher frequency of resistance to ciprofloxacin (51.4% vs 28.6%) and nalidixic acid (42.15% vs 28.6%) among the chicken meat, and ampicillin (50% and 17.1%) among the human stool was detected.

    Conclusion

    High percentage of poultry meat samples is contaminated with different Campylobacter species, which shows homology with the patients’ isolates in Tehran.

    Keywords: Foodborne diseases, Campylobacter, Drug resistance, Diarrhea, Poultry
  • Bechr Hamrita*, Emira Noumi, Ferdaws Hafi, Filomena Nazzaro, Mejdi Snoussi Pages 373-382
    Background and Objectives

    In this work, our aims were to investigate the antimicrobial resistance, and anti-quorum sensing activities of Punica granatum L. methanolic extract.

    Materials and Methods

    Antibacterial and antifungal activities were performed against thirteen bacteria and five fungal pathogens. Ultra-high performance liquid chromatography was used to identify the polyphenolic extract. The inhibition of pyocyanin production, proteolytic and elastolytic activity and swarming motility in Pseudomonas aeruginosa PAO1 test strain were estimated.

    Results

    The methanolic extract from P. granatum L. was dominated by chlorogenic acid (34.028 mg/g), rutin (26.05 mg/g), epicatechin (12.207 mg/g), gallic acid (11.157 mg/g), and caffeic acid 9.768 mg/g). Results showed antibacterial activities against almost all tested microorganisms with mean diameter of growth inhibition zone ranging from 6 ± 0 to 30 ± 0 mm for Candida species and from 6 ± 0 to 22.66 ± 0.57 for bacterial strains. The lowest minimal inhibitory concentrations were recorded for Listeria monocytogenes ATCC 19115 and Salmonella enterica CECT 529 (0.14 mg/ml, respectively). The anti-quorum sensing activity of methanolic extract against P. aeruginosa showed a significant inhibition of swarming motility and an attenuation in virulence factors like pyocyanin production at low concentrations.

    Conclusion

    The obtained results indicates that P. granatum L. extracts is a rich source of phenolic compounds and highlighted the possibilities uses of pomegranate to attenuate the expression of quorum sensing controlled factors in P. aeruginosa PAO1 strain.

    Keywords: Punica granatum L, Antimicrobial activities, Pseudomonas aeruginosa PAO1, Swarming, Proteolytic activity, Elastolytic activity
  • Mohd Jalil*, Nurul Zakaria, Nurul Suhaimi, Darah Ibrahim Pages 383-394
    Background and Objectives

    Endophytic fungi are believed to possess compounds as antibacterial agents. This study was designed to determine in vivo antibacterial activity of the crude extracts from Lasiodiplodia pseudotheobromae IBRL OS-64 against pathogenic bacteria.

    Materials and Methods

    The qualitative and quantitative screenings were performed using agar plug and disk diffusion antimicrobial tests, respectively. Besides that, the MIC and MBC value of the extracts were determined using broth microdilution assay and morphological changes of the bacterial cells exposed to the extract were observed under Scanning Electron Microscope (SEM).

    Results

    Agar plug diffusion assay revealed that V. parahaemolyticus ATCC 17802 and Exiguobacterium profundum IBRL MA6 were the most sensitive to the extract with the size of inhibition zones of 11 to ≤ 20 mm. The MIC and MBC values of the extract varied depending on the test bacteria. Observation through SEM revealed that the bacterial cells exposed to the extract experienced severe damage such as irregular shape with crumpled and shrunken cells which led to cell death.

    Conclusion

    The data suggest that the crude extracts of L. pseudotheobromae IBRL OS-64 exert antibacterial activity against test bacteria and principally affect the cell wall in growing pathogenic bacterial cells.

    Keywords: Antibacterial agents, Disk diffusion antimicrobial tests, Crude extracts
  • Sara Sadeqi, Abdolrazagh Hashemi Shahraki, Farhad Nikkhahi, Amir Javadi, Seyed Mohammad Amin Marashi * Pages 395-401
    Background and Objectives

    In the third world and developing countries, hospital sewage is mixed with municipal wastewater. The treated effluent contains dangerous bacteria released into the environment and used in the irrigation of agricultural products, and eventually these bacteria may endanger the human health through foods. Antibiotic-resistant bacteria are mostly found in hospital wastewater. In water and wastewater treatment plants, large amounts of toxic and polluting substances are removed and destroyed, but this process does not eliminate bacteria.

    Materials and Methods

    Wastewater samples from 22 hospitals in Iran were collected and in the meantime specific phages (against drug-resistant pathogenic bacteria) extracted using the bilayer agar technique. Phage amplification was performed by employing a fermenter after phage identification. Amplified phages were added to the primary sedimentation pond using New-Brunwick biofermenter BioFlo/Celligen®115 and the bacterial count was evaluated for the desired bacteria.

    Results

    Our phage cocktail was able to reduce 99.8%, 99.4%, 99.5%, 99.8%, 99.7%, 99.8%, 99.6% and 99.9% of E. coli, E. faecium, E. faecalis, K. pneumoniae, A. baumannii, P. aeruginosa, S. maltophilia and S. aureus counts respectively.

    Conclusion

    The application of phage cocktails can remarkably help improve personal hygiene, the environment, and the optimization of surface water.

    Keywords: Wastewater, Ponds, Bacteriophages, Environmental pollution, Drug resistance
  • Chiman Karami, Kamyar Mazloum Jalali, Shahram Jalilian, Gholamreza Khataminia, Somayeh Biparva Haghighi, Mohammad Karimi Babaahmadi, Reza Taherkhani, Manoochehr Makvandi* Pages 402-409
    Background and Objectives

    Human adenovirus type 8 is a highly contagious eye disease and is considered as the most common epidemic keratoconjunctivitis worldwide. The virus may alter the course of detection as mutations and recombination in surface antigens are associated with binding and pathogenesis in human adenovirus. The recognition of new recombinant human adenovirus has been based on sequencing of three genes, penton base, hexon and fiber.

    Materials and Methods

    50 suspected samples of ocular keratoconjunctivitis were selected over 6 months. Following DNA extraction from isolates positive for cytopathic effect in each well, the complete sequences of hexon, fiber, and penton regions were performed on the genome of human adenovirus isolates using PCR. The sequences of capsid genes, including hexon, fiber, and penton were assessed to observe the evidence of recombination at the molecular level using genetic tools.

    Results

    The results of nucleotide and amino acid sequence of 5/ 50 patients with epidemic keratoconjunctivitis positive for hypervariable region of hexon (132aa-449), hypervariable of knob fiber (183aa-362) and hypervariable penton (106aa-466) isolates showed nucleotide and amino acid identity of 98% and 99.41%, 99% and 100%, 95% and 99.72% with hexon, fiber and penton of human adenovirus 8 subtypes. The results of phylogenetic tree and Simplot of the entire sequences and hypervariable regions of isolated hexon, fiber and penton showed all the isolates of human adenovirus from Ahvaz, Iran, were clustered with human adenovirus 8A, B, E, P and J, subtypes isolated strains from different regions of the world.

    Conclusion

    The results of this study revealed that the human adenovirus isolates from patients with epidemic keratoconjunctivitis were closed to human adenovirus 8A, B, E, P and J subtypes. To determine the emergence of new human adenovirus D8 subtypes strain, analysis of complete genome sequence of human adenovirus was required.

    Keywords: Human adenovirus, Keratoconjunctivitis, Infections, Evolution, Recombination
  • Asma Bahrami, Ali Akbar Pourfathollah, Masoud Parsania, Hossein Mehrabi Habibabadi, Zohreh Sharifi * Pages 410-416
    Background and Objectives

    Despite the increased sensitivity of screening tests, the HBV can be transmitted during the window period and occult hepatitis B infection. The purpose of this study was to evaluate HBV markers and prevalence of OBI among HBsAg negative blood donors in Golestan province.

    Materials and Methods

    Anti-HBc (IgM and IgG), anti-HBs and anti-HBe tests on 4313 serum samples (HBsAg negative) were performed by ELISA method. Also, all samples for the presence of HBV- DNA were tested by using NAT methods. SPSS software and chi-square test were used for data analysis.

    Results

    Of the 4313 samples, 384 (8.9%) sera were anti-HBc positive. Also, of 384 anti-HBc positive samples, 302 (78.65%) were anti-HBs positive and 152 (39.6%) were anti-HBe positive. Thirty-nine (0.90%) samples were anti-HBc positive, anti-HBs negative and anti-HBe negative. HBV-DNA was not detected in any of specimens.

    Conclusion

    Based on the results of retesting the isolated anti-HBc samples that after one year recalling, had undetectable HBV-DNA and for the prevention of the decreasing of healthy blood donation (due to false positive anti-HBc) and preservation of the blood supplies; Individual Donor Nucleic Acid Testing (ID-NAT) along with the anti-HBc testing for the improving blood safety is recommended.

    Keywords: Hepatitis B surface antigen, Blood donors, Iran, Hepatitis B infection
  • Zeynab Yassin, Zahra Salehi, Mohammad Soleimani, Ensieh Lotfali, Mahsa Fattahi*, Somayeh Sharifynia Pages 417-422
    Background and Objectives

    Fusarium species are known to be one of the common causes of keratitis. This study was conducted to identify Fusarium spp. causing keratitis and to investigate their genetic diversity using TEF1 and RPB2 gene sequences.

    Materials and Methods

    Twenty-four clinical isolates of Fusarium were isolated from the patient with keratitis. Phylogenetic analysis of two-locus of the 24 clinical isolates and three reference strains was carried out using the maximum parsimony and RAxML methods.

    Results

    Based on gene sequences of the 24 clinical isolates, 17, 4, and 3 isolates were identified as Fusarium solani species complex (FSSC), Fusarium fujikuroi species complex (FFSC), and Fusarium oxysporum, respectively. FFSC include F. proliferatum (n=1), F. globosum (n=1), F. verticillioides (n=1), and F. brevicatenulatum (n=1), respectively.

    Conclusion

    Given that sequence of a sole gene can be challenging and on the other hand, due to the high resistance to antifungal drugs, identification of Fusarium species is of substantial significance. In this study, by designing a novel set of primers for the RPB2 area and using TEF1 primer, we were able to differentiate 24 Fusarium spp. isolated from patients with keratitis.

    Keywords: Keratitis, Fusarium oxysporum, Fusarium solani species complex, Fusarium fujikuroi species complex
  • Ashkan Faridi, Azam Amanizadeh, Seyyed Amin Ayatollahi Mosavi, Samira Salari, Davood Kalantar-Neyestanaki, Somayeh Sharifynia, Setareh Agha Kuchak Afshari * Pages 423-429
    Background and Objectives

    Candida albicans complex species are well known as the main cause of candidiasis, particularly among susceptible individuals. In this study, we report the genetic diversity of Candida spp. and the antifungal susceptibility pattern of the cryptic C. albicans complex isolates in Kerman, Iran.

    Materials and Methods

    A total of 112 yeast isolates were obtained from different clinical samples, and molecular identification was performed. All C. albicans complex isolates were tested for susceptibility of them to amphotericin B, fluconazole, and itraconazole.

    Results

    The majority of clinical isolates were C. albicans complex (n=48) followed by C. glabrata complex (n=34), C. parapsilosis complex (n=21), and C. krusei (n=9). Among C. albicans complex, 45 isolates were C. albicans (94%), 2 isolates were C. dubliniensis (4%), and 1 isolate was C. africana (2%). Amphotericin B was the most active antifungal, whereas 8.9% and 6.7% of the isolates were resistant to fluconazole and itraconazole, respectively.

    Conclusion

    Regarding the high incidence of Candida infections particularly in susceptible populations and the emergence of an infrequent yeast species with elevated MICs, which is indistinguishable with conventional methods, developing accurate molecular methods for laboratory diagnosis should be considered in the clinical setting.

    Keywords: Candida albicans, Candidiasis, Polymerase chain reaction, Amphotericin B, Itraconazole
  • Hoang Nguyen*, Thi Khanh Linh Nguyen, Thi Thuy Ung, Thi Thao Nhi Mai, Thi Nhu Hoa Tran, Viet Quynh Tram Ngo, Van An Le Pages 430-433

    Melioidosis is an emerging infection, a potentially fatal tropical disease caused by Burkholderia pseudomallei in humans and animals, endemic in Southeast Asia and northern Australia. Diagnosis remains problematic due to its similarity to many other infections. The lack of clinical awareness and correct microbiological diagnosis contributes to the misidentification of melioidosis. We present a melioidosis case, which was misdiagnosed with pneumonia and septicemia due to Aeromonas salmonicida, leading to ineffective prolonged-course antibiotic treatment for the patient.

    Keywords: Diagnostic errors, Melioidosis, Burkholderia pseudomallei, Aeromonas salmonicida, 16S ribosomal RNA