فهرست مطالب
Archives of Clinical Infectious Diseases
Volume:15 Issue: 1, Feb 2020
- تاریخ انتشار: 1399/01/20
- تعداد عناوین: 11
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Page 2Background
The hospital environment usually involves in cross-colonization and/or outbreaks of carbapenem-resistant Acinetobacter baumannii (CRAB). This study aims to identify genetic diversity of environmental Acinetobacter baumannii (A. baumannii) isolates based on OXA-type carbapenems.
ObjectivesIt was intended to identify the environmental source of A. baumannii strains to control future infections and ongoing outbreaks.
MethodsSwab samples were collected from equipment, fluids and surfaces of intensive care units of five hospitals (H1 to H5). The susceptibility of the isolates was defined through disk diffusion method. blaOXA-51, blaOXA-58, blaOXA-23, and blaOXA-24 genes were detected by multiplex polymerase chain reaction (PCR) . Genetic diversity was investigated using ERIC-PCR. Mean values were compared using an Independent samples t-test.
ResultsThe mean number of Gram-negative bacilli colony per sample was significantly higher in moist surfaces (1.9 ± 2.37) than in dry surfaces and medical equipment (P < 0.05). Among 32 A. baumannii isolates, 17 (53.1%) were classified as CRAB, 13 (40.6%) as multidrug resistant (MDR) and six (18.8%) as extremely drug resistant (XDR) phenotypes. The isolates showed the most susceptibility to tigecycline (81.3%) and doxycycline (81.3%). Totally, 10 isolates (31.3%) carried blaOXA-23 and one isolate carried blaOXA-58, but none contained blaOXA-24. Typing of the strains provided seven single types (ST) and nine clusters (A-I). Two isolates in cluster B (different surfaces of H4) and two in cluster I (from ventilators of H3 and H1) were designated as common type (CT). In H4 and H1, different isolates belonging to different clusters were recovered from bed sheet and baby sink bath, respectively.
ConclusionsClonally-related blaOXA-23 positive CRABs occurred in the environment, especially on moist surfaces of hospitals. The distribution of the same clones in different hospitals may point to expansion of a specific clone which increases the risk of cross-colonization of vulnerable patients.
Keywords: Acinetobacter baumannii, Environment, Beta-Lactamases, Cross Infections -
Page 3Background
Methicillin-resistant Staphylococcus aureus (MRSA) is a significant threat to human health. It is a multidrug-resistant (MDR) pathogen capable of causing a variety of diseases. Also, MRSA is one of the most important nosocomial pathogens in burn infection. As a treatment strategy against MRSA infections, phage therapy has the potential of becoming an alternative remedy.
ObjectivesThe present study aimed to isolate and characterize a lytic bacteriophage from hospital sewage to be effective against burn wound-infecting MRSA isolates.
MethodsStaphylococcus aureus strains were isolated from hospitalized burn patients. The strains were confirmed as MRSA by the Kirby-Bauer disk diffusion method using penicillin, methicillin, and oxacillin, as well as the PCR assay for the mecA gene. The phage was isolated from the hospital sewage and tittered by the double layer agar (DLA) method. The spot test was used for host range determination. The latent period and burst size were estimated from a one-step growth curve. The phage morphology was observed by electron microscopy. The nature of the nucleic acid of the isolated bacteriophages was confirmed by Rnase A, Dnase I, and six restriction enzymes.
ResultsThe titer, latent period, and burst size of the isolated phage were determined to be 1 × 109 PFU/mL, 20 min, and 190 PFU per infected cell, respectively. It displayed a broad host range for MRSA bacteria by the spot test (27 out of 30 isolates). Electron microscopy observation demonstrated that the phage belonged to the Myoviridea family. Digestion profiles of Rnase A, Dnase I, and six restriction enzymes in 1% agarose gel electrophoresis showed that the genome of the isolated phage was a double-stranded DNA with a size of < ∼23 kbp.
ConclusionsThe isolated phage (MH-1) was active against a wide range of MRSA strains recovered from burn patients. Its specificity and remarkable lytic effects on MRSA strains emphasized that it could be a suitable candidate for use in prophylaxis and treatment of these clinical infections.
Keywords: Wastewater, Staphylococcus aureus, MDR, MRSA, Bacteriophage, Burn Patients -
Page 4Background
Tick-borne encephalitis virus (TBEV) is a neurotropic tick-borne virus circulating in vast geographical areas of the northern hemisphere. Although the presence of TBEV vector has been documented in north Iran, there is no information about the circulation of TBEV in the country.
ObjectivesThis study was designed in order to determinate the TBE serologic profile in the Mazandaran Province of Iran.
MethodsIn this cross-sectional seroepidemiologic study, from September to November 2018, 448 serum samples collected (by random sampling method) from general population residing in rural areas of Behshar, Galugah, Miandorud and Neka cities were evaluated for presence of anti TBEV IgG antibodies using a commercial Anti-TBE Virus ELISA (IgG) kit.
ResultsSixteen (3.6%) samples were detected as reactive, in which 43.8% had a history of tick bite or tick squish. The highest seropositivity was observed in farming/animal industry-related jobs (33.3%) or were housewives (33.3%). All reactive cases reported a history of consuming local unpasteurized dairy.
ConclusionsThis study provides first evidence on the circulation of TBEV in Northern Iran, where climatic conditions, presence of Ixodes ticks, and variability of mammalian hosts might contribute to TBEV establishment. Overarching investigations on tick vectors, animals, and human population would be recommended to shed light on the epidemiology of the virus in this region.
Keywords: Iran, Tick-Borne Encephalitis, Flavivirus, Seroepidemiologic Study -
Do Occupational Factors Affect the Immune Response to Hepatitis B Vaccination in Healthcare Workers?Page 5Background
Hepatitis B infection is a common blood-borne viral infection and a major public health problem, especially for health care workers. It is important to protect this group against this type of infection and vaccination is one of the most effective measures. Health care workers have some risk conditions such as shift work and stress in their occupational setting.
ObjectivesThis study was conducted to recognize if occupational factors can affect the immune response to the hepatitis B vaccine.
MethodsWe enrolled 508 staff from three large teaching hospitals of Iran who received three standard doses of 20 µg of recombinant HB vaccine. Subjects who had anti-HBs titers < 10 mIU were injected with the second series of hepatitis B vaccine.
ResultsIn this study, 451 (88.77%) subjects responded to the first series of HB vaccine. Moreover, 44 out of 57 participants, who had anti-HBs titers < 10 mIU after the first series of vaccination, responded to the second series of vaccination. This indicates that the rate of response to recombinant hepatitis B vaccine is nearly 97.44%. Some occupational factors were found to be associated with the low response to HB vaccine including job category, shift work, and working unit.
ConclusionsTo provide appropriate protection against hepatitis B infection for health care workers, in addition to vaccination, it may be helpful to provide appropriate shift work schedules to minimize sleep deprivation in them and consider a booster dose of the vaccine for health care workers who are physicians or work in critical units.
Keywords: Hepatitis B Vaccine_Health Care Worker_anti-HBS -
Page 6Background
It is estimated that more than 80% of cases of human infections are related to biofilm formation by invasive bacteria. So, in this study, we considered the activity of cellobiose dehydrogenase enzyme (CDH) isolated from Aspergillus niger, as an antibiofilm agent, on biofilm of clinical Staphylococcus epidermidis and Pseudomonas aeruginosa isolates.
MethodsIn this study, five standard strains of Aspergillus niger were purchased for CDH production. Of the 42 isolated bacterial strains, 24 strains were Staphylococcus epidermidis and 18 strains were Pseudomonas aeruginosa. Zymogram method was used for screening of CDH. The CDH activity was measured by monitoring the decrease in absorbance of 2, 6-dichlorophenolindophenol (DCPIP) spectrophotometrically. After cultivation and production of bacterial biofilms, 7 concentrations of the cellobiose prepared and CDH enzyme with a final concentration of 364 U/mL were considered on bacterial biofilms by microbroth dilution method.
ResultsOut of five standard strains of Aspergillus niger, only 1 strain have the highest production of CDH. The most effective dilution of cellobiose on growth inhibition of Staphylococcus epidermidis and Pseudomonas aeruginosa in liquid cultures as a function of cellobiose concentration in the presence of cellobiose dehydrogenase was in 12.5 µg/mL.
ConclusionsBased on the results of this study, it can be concluded that the CDH enzyme had a high potential for use as an antimicrobial agent. As shown, this enzyme had a high potential for eliminating bacterial biofilms. So, these results may provide a basis for alternative therapies for the treatment of infections related to clinical biofilm producing bacteria.
Keywords: Biofilm, Staphylococcus epidermidis, Pseudomonas aeruginosa Aspergillus niger, Cellobiose Dehydrogenase CDH -
Page 7Background
Hepatitis C virus (HCV) infection is an important public health hazard, with approximately 71 million chronically HCV-infected individuals around the world.
ObjectivesThis study was designed to provide epidemiologic information on HCV, evaluate the possible route of transmission and its associated risk factors, and characterize the prevalence and distribution of HCV genotypes among HCV-infected patients in Fars Province, Southern Iran.
MethodsThis cross-sectional descriptive-analytical study was performed with the medical records of patients with HCV infection who had referred to the Gastroenterohepatology Research Center, Shiraz, Iran. The extracted data had been gathered from 1991 to 2016. The data included the time of diagnosis, demographic information, information on the course of the disease (including symptoms at disease onset), history of exposure to possible routes of transmission, risk factors, HCV genotype (if available), and family history of HCV infection. The relationship between two categorical variables was determined using the chi-square or Fisher’s exact tests. The relationship between categorical and quantitative variables was tested by one-way ANOVA. The Kendall-tau test was used to show the changing trends of risk factors regarding age and year groups. Univariate analysis was done and odds ratios were calculated to determine the relationship between genotypes and possible routes of HCV transmission.
ResultsFrom the total of 1,959 patients, 1,748 (88.20%) were males. An analysis of the trend of possible risk factors showed that the prevalence of cupping, intravenous drug use (IVDU), non-intravenous drug use (non-IVDU), penetrating trauma, tattooing, and high-risk sexual behaviors significantly increased over the study period. A significant reduction was observed in the rate of major thalassemia. The most prevalent HCV genotype was genotype 1 (49.3%), followed by genotype 3 (39.6%). Multivariate analysis of the possible routes of transmission revealed that cupping was associated with the increased risk of HCV genotype 1 infection.
ConclusionsThis study reports non-IVDU as the most common associated risk factor and genotype 1 as the most prevalent genotype in patients infected with HCV. Knowing risk factors can lead to making better policies and implement more effective interventions to prevent the spread of HCV infection.
Keywords: Risk Factor, Substance Abuse, Blood Transfusion, Genotype, Hepacivirus -
Page 8
Cystic echinococcosis disease is a parasitic and zoonotic disease which is caused by Echinococcosis granulosus, which is endemic in Mediterranean Region and Middle East countries, including Iran. Cyst formation usually occurs in the liver and grows slowly in a spherical shape. The patients are usually asymptomatic until the lesion reaches a significant size or becomes complicated by rupture. Hepatic lesions are usually single. Diagnosis could be made on the basis of imaging studies including computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound study, especially for liver involvement. Serologic studies are usually helpful and antibody detection is more sensitive than antigen. This article introduces a middle aged man who was presented to the emergency department with acute pleuritic chest pain. Further evaluations revealed coexisting liver and chest hydatid cyst with rupture of the liver cyst in to the pleural cavity, following rupture of the diaphragm. Then diagnosis and treatment are discussed.
Keywords: Hydatid Disease, Cystic Echinococcosis, Echinococcus granulosus Infection -
Page 9Introduction
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) caused by the JC virus (JCV).
Case PresentationA 47-year-old woman with no history of any underlying diseases was hospitalized at our center with a loss of consciousness and aphasia. The investigation of the patient’s history revealed that she had been hospitalized in another hospital a month earlier due to right hemiparesis and dysarthria. Brain imaging was repeated that revealed demyelinating lesions. The laboratory studies showed a positive human immunodeficiency virus (HIV) serology. The polymerase chain reaction (PCR) of the cerebrospinal fluid (CSF) for JCV turned out positive and the diagnosis of PML was established.
ConclusionsProgressive multifocal leukoencephalopathy should always be considered as an important differential diagnosis in patients with demyelinating brain lesions and HIV testing should be considered in these patients, as well.
Keywords: AIDS, Case Report, Human Immunodeficiency Virus, Acquired Immunodeficiency Syndrome, PML, JCV, Progressive Multifocal Leukoencephalopathy -
Molecular Detection of Isoniazid and Rifampin Resistance in Mycobacterium tuberculosis Isolates from Lorestan Province, Iran from 2014 to 2017Page 11Background
A rise in multidrug-resistant tuberculosis (MDR-TB), which is defined as the resistance to the two most effective first-line therapeutic drugs, Isoniazid (INH) and Rifampin (RIF), threatens global public health worldwide. Resistance of Mycobacterium tuberculosis to INH results from mutations in several genes most commonly in katG gene, and resistance to RIF is due to mutations in rpoB gene. Therefore, rapid diagnosis of MDR-TB is of high importance in controlling the disease progress and outcome. The accurate detection of the resistant TB strains can be accelerated by developing molecular tests.
ObjectivesThe aim of the present local study was to isolate MDR-TB from the patients who were the residents in the west of Iran and examination the frequency of MDR-TB between patients of Lorestan province for the first time and assess the mutations in the regions related to RIF/INH resistance via PCR and sequencing methods.
MethodsIn this study, 106 isolates of M. tuberculosis were selected in health centers of Lorestan, Iran from 2014 to 2017. After culturing M. tuberculosis isolates on Löwenstein-Jensen medium, classical susceptibility testing proportional method against INH and RIF was performed. After DNA extraction, PCR and sequencing were used to detect mutations related to RIF and INH resistance.
ResultsThe results demonstrated 3.8%, 0.9%, and 0.9% frequency for INH + RIF, INH and RIF resistance, respectively. Importantly, 4 out of 6 isolates harbored mutations in codon290 of katG gene. Also, these isolates contained mutations in codon339 of rpoB gene. No mutation was observed in inhA gene of M. tuberculosis isolates.
ConclusionsThe results suggest that molecular techniques can be used as a rapid method for the identification of drug resistance in clinical isolates of M. tuberculosis. DNA sequencing has a high sensitivity for the detection of resistance mutations to RIF and INH in MDR-TB cases. Also, the results showed that the most frequent resistance associated-mutations occurred in codon290 of katG and codon 339 rpoB gene segments.
Keywords: Multidrug Resistance, Mycobacterium tuberculosis, Isoniazid, Rifampin