فهرست مطالب

Jundishapur Journal of Microbiology - Volume:10 Issue: 9, 2017
  • Volume:10 Issue: 9, 2017
  • تاریخ انتشار: 1396/07/01
  • تعداد عناوین: 8
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  • Yousef Yahyapour, Kazem Aghajanipour, Seyed Mostafa Mir, Aynaz Khademian, Farzin Sadeghi * Page 1
    Background
    Human T-lymphotropic virus type 1 (HTLV-1) infection is a major health problem that effects a variety of endemic regions, including the Northeast of Iran. There is a lack of information about HTLV-1 prevalence among blood donors from Mazandaran province, Northern Iran.
    Objectives
    The aim of the present study was to investigate the prevalence of HTLV-1 infection among blood donors in Babol County, the most populated county in Mazandaran province with screening and confirmatory assays.
    Methods
    The present cross-sectional study was conducted on 503 blood donors. Serum samples from each blood donor were screened for HTLV-1 specific antibodies using the Enzyme-Linked Immunosorbent Assay (ELISA). Samples that were repeatedly reactive for HTLV-1 specific antibodies on serological screening were additionally confirmed by real time polymerase chain reaction (PCR) of HTLV-1 proviral DNA in Peripheral Blood Mononuclear Cells (PBMCs).
    Results
    Among 503 samples tested by serological enzyme linked immunosorbent assay (ELISA), 13 samples (2.6%) were repeatedly reactive (i.e. on at least 2 of 3 occasions). All repeatedly reactive samples were examined for the presence of the HTLV-1 proviral DNA in PBMCs by real time PCR confirmatory test, of which 1 sample was positive, resulting in HTLV-1 prevalence of 0.2%.
    Conclusions
    The present investigation contributes with new epidemiologic data reporting low prevalence rate for HTLV-1 among blood donors in Babol county of the Mazandaran province. Despite the low prevalence rate, the practice of screening of donated bloods in blood transfusion centers of Mazandaran province should be considered to decrease the risk of virus transmission in this region.
    Keywords: Blood Donor, Real Time Polymerase Chain Reaction, Human T, lymphotropic virus 1
  • Yan Jin, Chunzhong Dong, Chunhong Shao, Yong Wang, Yun Liu * Page 2
    Background
    The infection caused by metallo-β-lactamase (MBL)-producing Klebsiella pneumoniae has become a challenge to anti-infection treatments for newborns.
    Objectives
    The aim of this study is to investigate the molecular epidemiological characteristics of clonally related MBL-producing K. pneumoniae isolated from newborns in a hospital in Northern China.
    Methods
    A total of 16 isolates of carbapenem-resistant K. pneumonia were obtained from newborns between September 2011 and June 2014. Resistance genes were identified by PCR and sequencing. The isolates were classified by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).
    Results
    Our results show that the most prevalent genotypes of carbapenem-resistant K. pneumonia were ST54 and ST705. There were respectively 6 strains and 9 strains of K. pneumonia ST54 harboring the blaNDM-1 and blaIMP-4 genes, while the K. pneumoniae ST705 harbored the blaIMP-4 gene. Other resistance genes included extended-spectrum β-lactamases, plasmid-mediated AmpC enzymes and a class 1 gene cassette. The transferability of metallo-β-lactamase was determined by conjugation experiments, which showed that the blaNDM-1 and blaIMP-4 genes were transferable and likely through a plasmid-mediated event.
    Conclusions
    Our results showed that New Delhi metallo-beta-lactamase-1 (NDM-1) and imipenemase-4 (IMP-4) carbapenemases were the major players responsible for the carbapenem-resistance. Co-production of NDM-1 with CTX-M-15 in K. pneumoniae isolates was detected for the first time in our neonatal intensive care unit. Early detection of these drug resistance genes will help in prevention and control of the infection of K. pneumonia.
    Keywords: Molecular Epidemiology, Beta, Lactamases, Infant, Newborn, Klebsiella pneumonia
  • Fulya Bayindir Bilman *, Baris Cicek, Revasiye Gulesen, Belkis Levent Page 3
    Background
    Salmonellosis is still being reported as the second most common food-borne infection of bacterial origin. The most common serotypes worldwide as salmonellosis agents are Salmonella enterica subsp. enterica serotype enteritidis (S. enteritidis) and S. enterica subsp. enterica serotype typhimurium (S. typhimurium).
    Objectives
    In the current study, the researchers investigated food associated S. enteritidis outbreak in factory workers of Turkey.
    Methods
    The same meatball preparation that was consumed by the patients for lunch and dinner was responsible for the food poisoning on July 2014, when 257 workers in the same factory sought medical care. Among 257 individuals with diarrhea, abdominal pain, headache, fever, and vomiting, 48 (19%) were hospitalized. Stool samples were plated on Salmonella-Shigella agar and Eosine Methylene Blue agar plates and incubated at 37°C. Colonies morphologically resembling Salmonellae were selected for further identification on the next day using API 20E.
    Results
    During the outbreak, 10 out of 48 (21%) stool samples and 1 out of 25 (4%) blood culture from patients were positive. On serotyping, the isolates were identified as S. enteritidis (9,12; g,m;-) by the agglutination test. Pulsed field gel electrophoresis (PFGE) used for epidemiological analysis of the isolates showed a similar PFGE pattern. Pulsed field gel electrophoresis analysis was performed by XbaI enzymes. The antibiotic susceptibility tests of isolates were studied according to clinical and laboratory standards institute (CLSI) suggestions by using the disc diffusion method. All isolates were susceptible to ampicillin, nalidixic acid, ciprofloxacin, trimethoprim/sulfamethoxazole, tetracycline, kanamycin, chloramphenicol, gentamicin, ceftazidime, and cefotaxime.
    Conclusions
    All patients in the study were treated with ciprofloxacin 2 × 750 mg/day and returned to work on the 7th day.
    Keywords: Outbreak, Pulsed Field Gel Electrophoresis, Antimicrobial Susceptibility, Salmonella enteritidis
  • Zhao Qingxin *, He Jing, Ye Kaixia, Wang Jian, Kang Yijun, Shen Min, Wang Huanli Page 4
    Background
    Streptolysin O (SLO) from Streptococcus pyogenes could oligomerize to form large pores on the membrane of some eukaryotic cells. Because of the action, SLO had multifaceted applications in animal cell biology and medicine science. In the previous researches, the highest yield of recombinant expressed SLO might be no more than 124 mg/L medium.
    Objectives
    A fusion protein of pectate lyase and streptolysin O (PEL-SLO) was highly expressed with the pectate lyase (PEL, from Aspergillus nidulans) as fusion partner. The expression, purification, and hemolysis characteristics of this fusion protein were researched.
    Methods
    The SLO gene in this study was from S. pyogenes NZ131 and the pectate lyase gene from A. nidulans GR5. Escherichia coli BL21 (DE3) was used as expression host and pET-28a () plasmid as expression vector. Ni2+nitrilotriacetate-agarose column was used for protein purification. The fusion protein activity was measured by monitoring hemolysis of sheep red blood cells.
    Results
    In shaking flask fermentation, the goal protein expression might be higher than 600 mg/L culture at 0.6 mM IPTG, 25°C, and 200 rpm for 36 hours, about 5 fold of what was previously reported. The purified PEL-SLO fusion protein had a specialty of 1 × 107 HU/mg, about 10 fold of natural SLO. For sheep red blood cell, PEL-SLO fusion protein exhibited its optimal hemolysis level at pH 6.5 and 30 - 40°C.
    Conclusions
    The research demonstrated that PEL might have promoted SLO expression and strengthened its activity.
    Keywords: Pectate Lyase, Streptolysin O, Fusion Expression, Escherichia coli
  • Arshad Javaid, Irfan Ullah *, Mazhar Ali, Anila Basit, Waqas Ahmad, Faisal Younis, Afsar Khan, Ziaullah Shah, Zahid Ahmad Butt Page 5
    Background
    Tuberculosis remains a major health problem with more than 3 million deaths and 9 million new cases annually. Pakistan ranks 5th in the top 22 tuberculosis burden countries. Prevalence of all tuberculosis cases is 342 per 100,000 individuals in Pakistan.
    Objectives
    The objective of the present study was to assess the frequency and pattern of tuberculosis in a population from Khyber Pakhtunkhwa.
    Methods
    This prospective study was conducted in programmatic management of drug resistant tuberculosis unit lady reading hospital Peshawar, Pakistan between January, 2014 and December, 2014. A total of 1330 specimens from suspected drug resistant tuberculosis patients were analyzed by light-emitting diodes-fluorescence microscopy (LED-FM). The SPSS 18 software was used for data analysis.
    Results
    Of the 1330 drug resistant tuberculosis suspect patients tested by LED-FM microscopy, 824 (62%) were smear positive for Mycobacterium and 306 (38%) were negative. Mean age was 30.92 ± 14.91 years. Out of smear positive cases, 462 (56.1%) were female, 722 (87.6%) were previously treated, and 446 (54.1%) were in
    Conclusions
    Female gender, previous treatment, and young age (
    Keywords: Mycobacterium, Light, Emitting Diodes, Fluorescence Microscopy, Sputum
  • Yuanyuan Xu, Li Wang, Xudong Sun, Xiaogang Xu, Ting Hu, Bo Dong, Tao Jing, Jian Han *, Ying Zhang** Page 6
    Background
    Staphylococcus aureus is a prominent pathogen responsible for human pyogenic and nosocomial infections. Although numerous studies on S. aureus L-forms and virulence are available in the literatures, there are still various impediments in the research methods employed.
    Objectives
    This study aimed to perform fluorescence reporter in studying S. aureus L-form and its virulence, and wild strain virulence.
    Methods
    Newman-pCM29 strain which can express green fluorescent protein (GFP) was constructed and used to detect S. aureus L-form formation and virulence in vitro and in vivo.
    Results
    “Fried egg” like L-form colonies of GFP reporter S. aureus and the dense core of the colonies embedded into soft agar can be observed obviously. GFP reporter can contribute to preparing L-form suspension for injection and track the protoplasts and reverted cells in lesions of mice. GFP reporter, also, can help to detect S. aureus wild strain distribution and inflammation scope in lesions, and the fluorescence intensity can be used as an effective surrogate to represent the bacterial quantity in lesions. Fluorescence can improve to distinguish the colonies of varying sizes derived from the injected bacteria or from contaminants.
    Conclusions
    Fluorescence reporter in S. aureus is a powerful tool which can provide new insight into S. aureus L-form formation in vitro and its fate in vivo, and wild strain virulence in vivo in a non-traditional manner.
    Keywords: Fluorescence Reporter, GFP, L, Form, Virulence, Staphylococcus aureus
  • Hadi Mirahmadi, Maryam Rafee, Jalal Zaman, Ahmad Mehravaran, Reza Shafiei * Page 7
    Background
    Plasmodium vivax and P. falciparum have been detected in south east of Iran. Plasmodium vivax has a higher prevalence in this area. Point mutation in P. vivax dihydrofolate reductase (pvdhfr) gene is the key mechanism of Sulfadoxine and Pyrimethamine (SP) resistance.
    Objectives
    This study aimed at investigating pvdhfr mutations and haplotypes in Sistan and Baluchestan endemic province of Iran.
    Methods
    Seventy-five blood samples from Sistan and Baluchistan province of Iran, infected with P. vivax, between years 2013 and 2015, were enrolled in this study. The samples were examined for probable point mutations in pvdhfr gene using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and sequencing methods.
    Results
    Most of the isolates (59%) had wild type codons at 4 locations of pvdhfr gene. The F57S58T61N117 was the most common haplotype among the mutant cases (24.3%); in these cases, the haplotypes with triple and quadruple mutations in 57, 58, 61, and 117 codons were not identified. In addition, haplotypes with double mutations at location FRTN (7.7%) and FRTT (2.6%) were identified in studied cases.
    Conclusions
    This study showed that the presence of mutant pvdhfr haplotypes, which are resistant to the SP is increasing, therefore, performing a molecular surveillance via the PCR method in endemic areas is very important.
    Keywords: Drug resistance, Sistan, Baluchistan, Iran, Plasmodium vivax, dhfr Gene
  • Hui Li, Hua Zhou, Xi Li, Jianfeng Wang, Ying Fu, Yan Jiang, Yunsong Yu * Page 8
    Background
    The carbapenem resistance in Acinetobacter baumannii (CRAB) is a global health problem because of the worldwide distribution of the bacteria and a few available therapeutic options. Colistin is considered as the last resort to treat the infection. At present, there are several methods to detect the colistin susceptibility, including broth microdilution with 0.002% polysorbate 80 (BMD-P80), the E-test, broth microdilution (BMD), and agar dilution (AD). However, the differences in efficacy between the methods are not well studied.
    Objectives
    The current study aimed at evaluating the 4 available methods to test in vitro susceptibility to colistin and observing the degree of heteroresistance in CRAB species in China.
    Methods
    To evaluate the methods, a total of 202 CRAB species isolated from 12 hospitals in Zhejiang province, China, collected from January to December in 2010 were employed retrospectively. Colistin minimum inhibitory concentrations (MICs) were determined by the 4 different methods. Population analysis profiles (PAPs) were also conducted in 29 CRAB strains.
    Results
    The proportions of colistin-sensitive isolates were 100%, 100%, 99.5%, and 90.6% by BMD-P80, E-test, BMD, and AD methods, respectively, according to the EUCAST breakpoints. The AD methods produced an excessive number of major errors (MEs) (9.4%), while E-test and BMD produced 0.5% MEs. Moreover, the AD method resulted in a minimum essential agreement (EA) at 9.4%, and 179 isolates obtained a higher (≥ 3 log 2) number of dilutions than the BMD-P80. Not very major errors (VMEs) were found by any of the tested methods. In 29 selected CRAB isolates, a total of 31% were heterogeneous and the rate of heteroresistance was also 31%.
    Conclusions
    The AD method was not a prior choice of in vitro colistin susceptibility testing because it led to false colistin resistance results. E-test, BMD, and BMD-P80 may be more reliable to test the susceptibility when colistin is considered as a potential therapeutic agent. A high rate of heterogeneous and heteroresistant species were found in CRAB in China; it highlighted the importance of MICs monitoring before and through the colistin therapy period.
    Keywords: Colistin Susceptibility, Population Analysis Profiles, Acinetobacter baumannii