Survey of clinical features, pathogenesis and therapeutic options for Ebola haemorrhagic fever

      The genus Ebola virus first was recognized in 1976, when two outbreaks occurred in Zaire and Sudan. Ebola virus disease (EVD) is a highly contagious disease that can affect both human and nonhuman primates: Zaire ebolavirus (ZEBOV), Sudan ebolavirus (SEBOV), Côte d’Ivoire ebolavirus (CEBOV), Bundibugyo ebolavirus (BEBOV) and Reston ebolavirus (REBOV) are five members of the Filoviridae family that can cause haemorrhagic fever. EVD is transmitted by direct contact with contaminated blood or other biological fluids of the infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest. Ebola is responsible for different clinical futures that can be ranged from fever, headache, arthralgia, myalgia, abdominal pain, anorexia and vomiting to severe respiratory disorders, viral hemorrhagic fever, cardio-vascular disorders and hypovolaemic shock.  Although there is no specific treatment for EVD, considerable advances like use of monoclonal antibody, intefron and Favipiravir/T-705 as effective chemotherapeutic agent in treatment of EBV have been made. To date, 25 outbreaks of EVD have been reported. Hence, EVD as a zoonotic disease should be more focused not only in endemic area but also in throughout the world. Awareness of the disease and routes of transmission and also continuous surveillance to combat disease and outbreaks is necessary

Study of flagellin profiling in multidrug resistant Pseudomonas aeruginosa (MDRPA) isolated from burn wound infections, Tehran, Iran

     Nosocomial infections of multidrug-resistant Pseudomonas aeruginosa (MDRPA) are a growing concern in hospitalized patients in burn centers. The aim of this study was to investigate the flagellin profiling and antibiotic susceptibility of P. aeruginosa isolated from burn wound infections. During 8 month study, 73 clinically P. aeruginosa isolates collected from patients hospitalized in burn ward. P. aeruginosa isolates were identified using standard laboratory procedures. In vitro susceptibility of clinical isolates of P. aeruginosa to 6 antimicrobial agents were investigated by Clinical and Laboratory Standards Institute (CLSI 2012) Kirby-Bauer disk diffusion assay. The frequency of different type of flagellin was investigated by using specific primers and by PCR method. The resistance rates of our isolates to 6 tested antimicrobial agents were relatively high. Imipenem has good activity while tobramycin and ciprofloxacin do not have any effect on P. aeruginosa isolates. Of 73 isolates 59 (80.8%) were multidrug resistant. Twenty eight of 73 isolates were resistant to all antibiotics. Agarose gel electrophoresis of chromosomal DNA exhibited that 59 isolates (80.8%) of P. aeruginosa had type A flagellin while only 14 isolates (19.2%) had type b flagellin. Given the antibiotic failure treatment, it appears that alternative ways such as immunity to prevent of these infections could be informative. Our survey of flagellin profiling of multidrug-resistant P. aeruginosa isolates exhibited high frequency of type a flagellin as a major virulence factor has important role of immunity against infections caused by MDRPA. Functional surveillance of multidrug-resistant P. aeruginosa in order to prevention of resistance dissemination is necessary.

Prevalence of blaCTX-M gene in multi-resistant Escherichia coli isolated from Urinary Tract Infections, Tehran, Iran

Background:The emergence and increase in the incidence of Extended-spectrum beta lactamase (ESBL) producing Escherichia coli has become an emerging challenge especially in hospitalized patients with UTI. The aim of the present study was to survey the frequency of bla CTX-M genotype in ESBL producing E. coli isolated from hospitalized patients with UTI and determination of their antibiotic resistance pattern.Material and methodsA total of 135 E. coli isolates were collected from isolated from patients with UTI. The isolates were subjected to confirmatory phenotype tests for the presence of ESBL. 75 E. coli isolates were confirmed as ESBL-positive by means of the Double disc synergy test. In vitro susceptibility of ESBL isolates to 15 antimicrobial agents amoxicillin, penicillin, ceftazidime, cefotaxime, cefoxitin, ceftriaxone, cefixime, cephalexin, co-trimoxazole, gentamicin, nalidixic acid, ciprofloxacin, nitrofourantoin, amikacin and imipenem was performed by Kirby-Bauer’s Disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI, 2012) guideline. PCR method was used to identify bla CTX-M gene in 75 ESBL positive strains.Results:PCR and sequence analysis showed that 75 (55.5%) isolates produced bla CTX-M genes. In vitro susceptibility of ESBL producing E. coli showed that all of them were resistant to amoxicillin and penicillin and The rates of resistance to the majority of tested antibiotics varied between 61% to 100 %, with the exception of amikacin (14.7%) and imipenem (2.7%). Our results showed that the frequency of bla CTX-M was strikingly high (93.3%).Conclusion:These data confirmed that the frequency of bla CTX-M genes were high among E. coli isolated from patients with UTI. The trend of multidrug-resistant profile has been associated with bla CTX-M gene is alarming. Therefore, it is very important to establish a routine screening of ESBL in clinical isolates to prevent dissemination of resistant isolates in health care settings

Pathogenesis, Risk Factors, and Therapeutic Options

The incidence and mortality rate of Clostridium difficile infection have increased remarkably in both hospital and community settings during the last two decades. The growth of infection may be caused by multiple factors including inappropriate antibiotic usage, poor standards of environmental cleanliness, changes in infection control practices, large outbreaks of C. difficile infection in hospitals, alteration of circulating strains of C. difficile, and spread of hypervirulent strains. Detection of high-risk populations could be helpful for prompt diagnosis and consequent treatment of patients suffering from C. difficile infection. Metronidazole and oral vancomycin are recommended antibiotics for the treatment of initial infection. Current treatments for C. difficile infection consist of supportive care, discontinuing the unnecessary antibiotic, and specific antimicrobial therapy. Moreover, novel approaches include fidaxomicin therapy, monoclonal antibodies, and fecal microbiota transplantation mediated therapy. Fecal microbiota transplantation has shown relevant efficacy to overcome C. difficile infection and reduce its recurrence

Characterization of coagulase-negative staphylococci isolated from hospitalized patients in Tehran, Iran

     Coagulase-negative staphylococci (CNS) are a main cause of nosocomial infection. The main purpose of this study was to determination of frequency of CNS isolates in in hospitalized patients and their susceptibility pattern to antimicrobial agents. During 11 month study, 65 CNS clinical isolates were recovered from hospitalized patients in different wards of hospital. In vitro susceptibility of isolates to 12 antimicrobial agents Penicillin; Ampicilin; Cephalothin; Cefoxitin; linezolid; Nitofurantoin; Erythromycin; Norfloxacin; Gentamicin; Vancomycin; Chloramphenicol and Oxacillin was performed by Kirby-Bauer’s Disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) criteria. Out of 1875 samples of hospitalized patients 65(3.47%) patients were infected with CNS. Twenty one (32.3 %) were isolated from the urine samples, 17(26.1%) from sputum, 15(23.1%) from pus samples, 8(12.3 %) from ear swabs, 3(4.7%) from fluid and 1(1.5%) from blood sample. All of CNS isolates were sensitive to nitrofurantoin. The rates of resistance to the majority of antibiotics tested varied between 4.5% and 100 %. The rate of resistance to beta lactam antibiotics, Chloramphenicol, erythromycin, gentamycin was high (more than 70%). The most of isolates remained susceptible to linezolid, and nitofurantoin. All of isolates were susceptible to vancomycin. Multi-drug resistant CNS with reduced susceptibility to linezolid and nitrofurantoin are emerging pathogens of clinical concern. Monitoring of antibiotic resistance with attention to multi-resistant profile and aware to practitioners in the field is necessary

Fecal carriage of Escherichia coli and Klebsiella spp. as major reservoirs of clinically important resistance markers

Intestinal normal flora can become reservoirs of antibiotic resistance genes present among the strains responsible for nosocomial infections. It is suggested that gram negative intestinal bacterial flora have increased capacities to obtain antibiotic resistance genes and therefore can act as main reservoirs for transfer of resistance genes to other pathogenic bacteria. This study aimed to compare fecal carriage of clinically important resistance markers for more frequent members of enterobacteriacae between nondiarrheal and community associated diarrheal patients (control group) versus their counterparts from the patients with nosocomial infections (case group). 261 stool and 190 clinical samples were collected from outpatient and hospitalized patients from 6 hospitals in Tehran, Iran. The samples were cultured on MacConkey agar plates and colonies were identified by standard biochemical methods. Antibiotic sensitivity testing of the isolates against 13 antibiotics was performed according to the CLSI guideline using the disk diffusion method.   Among stool and clinical samples, more frequent identified enterobacteriaceae bacteria were included E. coli (58.99/ 3.15%), Klebsiella spp. (22.61/7.36%), and other members of enterobacteriaceae (8.86/1.06%), respectively. Overall, resistance against four of the main antibiotics (3th and 4th generation cephalosporins, gentamicin, imipenem, and ciprofloxacin) was significantly higher among the case group (50-75% versus 10-14%). Analysis of these results showed similar dissemination of resistance phenotypes among the isolates from the control group in ranges of 1.5-7.6% and 4.4% for E. coli and Klebsiella spp., respectively. Our results suggested that the fecal carriage of resistant phenotypes related to the β-lactam antibiotics in E. coli and Klebsiella spp. in compare to the clinical isolates is rapidly increasing. This may be caused by dissemination of β-lactamase producing E. coli in the community from the hospitals. There were no significant correlations between the two groups of the samples, as the clinical samples had shown 3 to 7 folds excess resistance phenotypes. Surveillance studies of the resistance patterns among the samples from different regions will provide awareness about dissemination of these bacteria within the community as reservoirs of main resistance markers

Relation between blaTEM, blaSHV and blaCTX-M genes and acute urinary tract infections

Objective: To survey the frequency of blaTEM, blaSHV and blaCTX-M genotypes in extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) isolated from hospitalized patients with urinary tract infection and the determination of their antibiotic resistance patterns. Methods: During 11-month study, 100 ESBL-producing E. coli were collected from 330 patients who met the definition of urinary tract infection. The phenotypic identification of ESBL was confirmed by double disk synergy test and combined disk diffusion test. In vitro, susceptibility to ESBL isolates than 14 antimicrobial agents was performed by Kirby-Bauer disk diffusion method. The frequency of blaTEM, blaSHV and blaCTX-M ESBL-producing E. coli was assessed by PCR method. Results: The frequency of ESBL-producing E. coli was 40.8%. In vitro, susceptibility to ESBL-producing E. coli showed that the majority of isolates were highly susceptible to amikacin (74%) and imipenem (91%). The rates of resistance to other antibiotics varied from 33% to 96%. Through 100 tested isolates, the prevalence of blaTEM, blaSHV and blaCTX-M genes was determined to be 67%, 45% and 74% respectively. In comparison with other bla genes, the frequency of blaCTX-M was strikingly high. Conclusions: Due to the increase of E. coli with multiple ESBL genes, continuous surveillance in order to use appropriate antibiotics and the control of infections is necessary

Aloe vera Gel: Effective Therapeutic Agent against Multidrug-Resistant Pseudomonas aeruginosa Isolates Recovered from Burn Wound Infections

Objective. Aloe vera is an herbal medicinal plant with biological activities, such as antimicrobial, anticancer, anti-inflammatory, and antidiabetic ones, and immunomodulatory properties. The purpose of this study was investigation of in vitro antimicrobial activity of A. vera gel against multidrug-resistant (MDR) Pseudomonas aeruginosa isolated from patients with burn wound infections. Methods. During a 6-month study, 140 clinical isolates of P. aeruginosa were collected from patients admitted to the burn wards of a hospital in Tehran, Iran. Antimicrobial susceptibility test was carried out against the pathogens using the A. vera gel and antibiotics (imipenem, gentamicin, and ciprofloxacin). Results. The antibiogram revealed that 47 (33.6%) of all isolates were MDR P. aeruginosa. The extract isolated from A. vera has antibacterial activity against all of isolates. Also, 42 (89.4%) isolates were inhibited by A. vera gel extract at minimum inhibitory concentration (MIC) ≤ 200 µg/mL. MIC value of A. vera gel for other isolates (10.6%) was 800 µg/mL. All of MDR P. aeruginosa strains were inhibited by A. vera at similar MIC50 and MIC90 200 µg/mL. Conclusion. Based on our results, A. vera gel at various concentrations can be used as an effective antibacterial agent in order to prevent wound infection caused by P. aeruginosa

Clostridium difficile Infection: Epidemiology, Pathogenesis, Risk Factors, and Therapeutic Options

The incidence and mortality rate of Clostridium difficile infection have increased remarkably in both hospital and community settings during the last two decades. The growth of infection may be caused by multiple factors including inappropriate antibiotic usage, poor standards of environmental cleanliness, changes in infection control practices, large outbreaks of C. difficile infection in hospitals, alteration of circulating strains of C. difficile, and spread of hypervirulent strains. Detection of high-risk populations could be helpful for prompt diagnosis and consequent treatment of patients suffering from C. difficile infection. Metronidazole and oral vancomycin are recommended antibiotics for the treatment of initial infection. Current treatments for C. difficile infection consist of supportive care, discontinuing the unnecessary antibiotic, and specific antimicrobial therapy. Moreover, novel approaches include fidaxomicin therapy, monoclonal antibodies, and fecal microbiota transplantation mediated therapy. Fecal microbiota transplantation has shown relevant efficacy to overcome C. difficile infection and reduce its recurrence

Characteriz ation of integrons and associated gene cassettes in Acinetobacter baumannii strains isolated from intensive care unit in Tehran, Iran

Objective: To determine the antimicrobial susceptibility patterns, the frequency of integrons and associated gene cassettes in Acinetobacter baumannii (A. baumannii) strains isolated from selected hospital intensive care units. Methods: During a ten-month period, 120 A. baumannii isolates were studied. The resistance rates to different classes of antimicrobial agents were determined. PCR was used to detect different types of integrons and associated gene cassettes. Results: The resistance rates to the majority of antibiotics tested were found to be between 39.3% and 99.1%. No isolate was observed to be resistant to colistin and polymyxin B. The rate of extensive drug-resistance among these clinical isolates was 62.5%. The prevalence of class 1 and 2 integrons was found to be 74.1% and 12.5%, respectively. Seven different gene cassettes (ampC, aacA4-catB8, ISAba1-blaOXA-23-GES-14, aadA2-cm1A6-GES-14-qacF, VIM-25-GES-24-qacF, dfrA5-ISAba1-blaOXA-51-blaOXA-40 and aadA2-GES-11-IMP-1) were observed in Class 1 integron-carrying strains. Three gene cassettes (IMP-4, VIM-2-VEB-aacA4 and dfrA2-sat-2-aadA4) were detected in class 2 integron-bearing A. baumannii strains. Conclusions: A high prevalence of integron was described among multidrug resistant A. baumannii in the hospital. The findings highlighted the need for continuous surveillance in order to prevent dissemination of multidrug resistance among A. baumannii strains in Iran