فهرست مطالب

Jundishapur Journal of Microbiology
Volume:11 Issue: 9, Sep 2018

  • تاریخ انتشار: 1397/06/14
  • تعداد عناوین: 7
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  • Emel Inegol Paykoc, Suheyla Turkyilmaz * Page 1
    Background

    In Turkey, Escherichia coli causing urinary tract infections (UTI) do not have current data on antibacterial resistance, extended spectrum β-lactamase (ESBL) enzymes types and virulence factors.

    Objectives

    In this study, the isolation of E. coli from patients with UTI, determination of antimicrobial resistance of isolates, and investigation of the presence of ESBL enzymes and pyelonephritis-associated P fimbriae types, were aimed.

    Methods

    Isolation E. coli from urine samples and identification were performed with conventional methods. Antibiotic resistance profiles were performed with the disc diffusion test (DDT). The presence of ESBL enzyme was investigated by the double disk diffusion test (DDDT). The presence of ESBL genes and P fimbriae genes were also investigated with PCR. The Chi squared test was used to compare the relationship between antibiotic susceptibility and resistance status in ESBL producing or non-producing and P fimbriae carrying and non-carrying isolates.

    Results

    It was determined that 50.3% and 41.9% of isolates were resistant to ciprofloxacin, trimethoprim sulfamethoxazole. It was demonstrated that 49.7% of isolates were phenotypically ESBL positive, while 59.4% were genetically positive. The percentages of genes detected with PCR were 32.3%, 31.6%, 21.1%, 2.3% for blaTEM, blaCTX, blaOXA, blaSHV, respectively. A total of 51 pap genes were detected in 27.0% (36/133) of the total isolates.

    Conclusions

    Extended spectrum β-lactamase producing E. coli infections associated with UTI increased in last years in Turkey. Further studies should be designed to investigate plasmids of ESBL positive E. coli stains isolated from UTI and whether plasmids are responsible for ESBL production

    Keywords: Antibiotic Resistance, Escherichia coli, Virulence Factors
  • Keyvan Pakshir *, Fatemeh Karimi, Kamiar Zomorodian, Saham Ansari, Hasti Nouraei, Alireza Gharavi Page 2

     

    Background

    Candida parapsilosis consists of three species of C. parapsilosis sensu stricto, C. metapsilosis, and C. orthopsilosis. Proteinase activity is considered as one of the major virulence factors in the pathogenicity of Candida species.

    Objectives

    We aimed to discriminate clinical isolates of the C. parapsilosis species complex through analysis of the secondary alcohol dehydrogenase (SADH) gene using BanI restriction enzyme and evaluation of proteinase activity among the isolates.

    Methods

    In this study, 71 clinical isolates identified as C. parapsilosis were included. The species were discriminated via analysis of SADH gene using S1F and S1R primers. The polymerase chain reaction (PCR) products were digested with restriction enzyme BanI. Proteinase activity of the species was evaluated using bovine serum albumin agar medium. To analyze the data, Fisher’s exact test was used.

    Results

    The results presented that out of the 71 species tested, 65 (91.5%) were C. parapsilosis sensu stricto, 6 (8%) were C. orthopsilosis, and no species were C. metapsilosis. Proteinase activity was observed in 70.1% and 80.3% of C. parapsilosis and C. orthopsilosis species, respectively.

    Conclusions

    In this study, the most dominant species identified by the molecular method was C. parapsilosis sensu stricto. The high rate of proteinase activity among the isolates indicates the importance of this enzyme as a virulence factor in the pathogenicity of this complex

    Keywords: SADH gene, PCR, BanI, Candida parapsilosis Complex
  • Chunchan Lin, Shuying Chen, Ye Jin, Jingjing Duan, Zhihao Hao, Shanshan Wang, Yinjuan Guo, Longhua Hu, Liangxing Wang, Fangyou Yu * Page 3
    Background

    In the recent decades, mupirocin and fusidic acid (FA) have become important antimicrobial agents for skin and soft tissue infections (SSTIs) and the eradication of staphylococci colonization.

    Objectives

    The present study aimed at determining the role of mupirocin and FA resistance in controlling Staphylococcus epidermidis infections and eradication of staphylococci colonization.

    Methods

    This study was conducted between January 2012 and December 2015, at a tertiary hospital in Wenzhou, east China, on 711 S. epidermidis clinical isolates collected consecutively from various specimens of inpatients. Polymerase chain reaction (PCR) and DNA sequencing were used to identify mupA conferring high-level mupirocin resistance and fusA mutations. Multi-locus sequence typing (MLST) based on nucleotide sequencing of seven housekeeping genes revealed distinct related clones of methicillin-resistant S. epidermidis (MRSE), as clinically significant isolates.

    Results

    Twelve FA-resistant S. epidermidis clinical isolates were positive for fusB, while only one was positive for fusC. All six S. epidermidis isolates with low-level mupirocin resistance were negative for mupA. However, 23 (35.38%) of 65 isolates with high level of resistance to mupirocin were found to carry this gene. Surprisingly, among 31 isolates with both mupirocin and FA resistance, only two were positive for fusB and only six were positive for mupA. More than 50% of the resistance for 71 mupirocin-resistant isolates and 56 FA-resistant isolates to non β-lactam included erythromycin, clindamycin, ciprofloxacin, gentamicin and trimethoprim-sulfamethoxazole. Among 31 S. epidermidis isolates with both mupirocin and FA resistance, 15, three, and two belonged to ST2, ST466, and ST23, respectively. ST125 and ST130 were found in one isolate, each. All 15 ST2 S. epidermidis isolates were MRSE with high-level resistance to mupirocin (MICs > 256 mg/L), with similar resistance patterns.

    Conclusions

    Taken together, the present study is the first report of resistance to both mupirocin and FA among S. epidermidis isolates. Dissemination of S. epidermidis ST2 clone with both FA and mupirocin resistance can cause trouble in controlling S. epidermidis infections and eradication of staphylococci colonization

    Keywords: Staphylococcus epidermidis, Mupirocin, Fusidic Acid, Resistance, Molecular Characteristics
  • Setareh Yousefi, Ali Mojtahedi *, Mohammad Shenagari Page 4
    Background

    Urinary tract infection (UTIs) caused by Escherichia coli is one of the most common human complications. The discriminate use of antibiotics leads to increasing multiple-drug resistance (MDR) in E. coli.

    Objectives

    This study aimed at investigating the frequency of fluoroquinolones resistance by detecting qnr genes and mutation in gyrA gene in clinical isolates of E. coli in the North of Iran.

    Methods

    This cross-sectional study was conducted on 309 E. coli isolates collected from major hospitals in Rasht, North of Iran. All isolates were identified by standard microbiological methods. Antimicrobial susceptibility testing was conducted by the disk diffusion method for the three quinolone antibiotics. The detection of gyrA, qnrS, qnrB, and qnrA genes was performed by the polymerase chain reaction (PCR) method. PCR products of gyrA gene were digested by HinfI enzyme to identify the mutation in gyrA gene by restriction fragment length polymorphism (RFLP) method.

    Results

    Of 309 tested E. coli isolates, the most common resistance was observed against nalidixic acid (60.2%) and the least common one against norfloxacin (40.5%). The prevalence of qnrS, qnrB, and qnrA genes was 4.5%, 73.1%, and 62.8%, respectively. Mutation in gyrA gene was observed in codon 83 in 56.3% of the strains.

    Conclusions

    In summary, despite the significant association of the investigated genes with fluoroquinolones resistance in these bacteria, the presence of these genes in susceptible strains suggested that some other possible mechanisms may also influence resistance against fluoroquinolones

    Keywords: Escherichia coli, Antibiotic Resistance, DNA Gyrase, qnr Genes
  • Yunbo Chen, Qiaodi Gui, Qiaomai Xu, Tao Lv, Silan Gu, Ping Shen, Jiazheng Quan, Yunhui Fang, Guangyong Ye, Lanjuan Li * Page 5
    Background

    Liver disease represents a risk factor for Clostridium difficile infection (CDI). However, CDI predisposition and its incidence in patients with chronic hepatitis B (CHB) have not been well-characterized.

    Objectives

    This study aimed at determining the incidence and risk factors of CDI in CHB patients without cirrhosis.

    Methods

    A retrospective case-control study was conducted on hospitalized patients in a Chinese tertiary hospital between June 2010 and June 2016.

    Results

    A total of 105 CHB patients without cirrhosis were included in the present study. Among these patients, 35 (33%) patients developed hospital-acquired CDI. A total of 35 toxigenic C. difficile strains were assigned to 15 different STs by multi-locus sequence typing (MLST). Multivariate analysis indicated that prolonged hospital stay (OR: 1.045; 95% CI: 1.006 to 1.086) and higher Charlson scores on admission (OR: 3.063; 95% CI: 1.602 to 5.857) were independent factors for the development of CDI among CHB patients without cirrhosis.

    Conclusions

    A high incidence of CDI was detected in this cohort of CHB patients. Both the prolonged hospital stay and higher Charlson scores made CHB patients more susceptible to hospital-acquired CDI. Greater emphasis on infection control measures and antimicrobial stewardship in patients with CHB during hospital admission is needed.

    Keywords: Infection_Hepatitis B Virus_Clostridium difficile
  • Huanqin Han *, Fan Mo, Wuying Zhang, Qingfeng Luo Page 6
    Introduction

    Enterococci are unusual etiological agents of bacterial meningitis. Meningitis caused by Enterococcus gallinarum, especially those that occur in immunocompetent hosts, is extremely rare. Moreover, community-acquired E. gallinarum meningitis might be extremely unexpected for a clinician and therefore easily misdiagnosed and mistreated.

    Case Presentation

    A 12-year-old boy presented with an acute onset of fever, headache and vomiting. The cerebrospinal fluid culture from lumbar puncture yielded an isolate that was identified as E. gallinarum. The therapeutic regimen was a combination therapy of rifampicin and high-dose intravenous penicillin. One day after starting treatment, the patient became afebrile. A repeated lumber puncture two weeks later showed few white blood cells in the CSF and no bacterial growth.

    Conclusions

    This case reveals an incident of meningitis caused by E. gallinarum in an immunocompetent host. The combined therapy of rifampicin and high-dose intravenous penicillin might be effective for treatment in such a case.

    Keywords: Enterococcus gallinarum, Meningitis, Penicillin, Rifampicin
  • Ali Raza, Muhammad Saleem, Muhammad Sohail Afzal * Page 7