Frequency and antimicrobial susceptibility of Shigella species isolated in Children Medical Center Hospital, Tehran, Iran, 2001-2006

AbstractAppropriate antimicrobial treatment of shigellosis depends on identifying its changing resistance pattern over time. We evaluated 15,255 stool culture submitted from July 2001 to June 2006 to the Laboratory of Children Medical Center Hospital. Specimen culture, bacterial identification, and disk diffusion susceptibility testing were performed according to National Committee for Clinical Laboratory Standards guidelines. From 15,255 stool samples, 682 (4.5%) were positive for Shigella species. The most common species of Shigella were S. flexneri (48%) and S. sonnei (45%); other results were S. dysenteriae (5%) and S. boydii (2%). The rate of Sensitivity to ceftriaxone (95%), ceftizoxime (94%), and nalidixic acid (84%) were among our isolates. Resistance to co-trimoxazole and ampicillin was 87% and 86%, respectively. S. flexneri was more multiresistant than other species (47.9%). Our isolates are overall most sensitive to ceftriaxone, ceftazidime, and nalidixic acid (> 84%). They were most resistant to co-trimoxazole and ampicillin (> 86%). Because resistance varies according to specific location, continuous local monitoring of resistance patterns is necessary for the appropriate selection of empirical antimicrobial therapy

Clinical Manifestations, Laboratory Findings, and Therapeutic Regimen in Hospitalized Children with Brucellosis in an Iranian Referral Children Medical Centre

Brucellosis is considered a known widespread zoonotic disease and is endemic in Mediterranean region, like Iran. This study reviewed the clinical manifestations, laboratory findings, and therapeutic regimen in childhood brucellosis in Iran. In this retrospective study, we reviewed hospital-records of 34 consecutive children with a confirmed diagnosis of brucellosis among a total number of 10,864 patients admitted to Children\u2019s Medical Center, Tehran, Iran, between 2002 and 2010. Among the patients diagnosed with brucellosis, 22 (65%) were admitted during spring and summer. Clinical findings of these patients at admission were arthritis, splenomegaly, hepatomegaly, lymphadenopathy, maculopapular skin rashes, and fever. Anaemia (53%) and leukopenia (33%) were the most common findings in the children. Only one patient had presented with leukocytosis. Four children (12%) were thrombocytopenic, and none of patients had pancytopenia. Blood cultures were positive in 5 patients (23%). Only one patient underwent bone-marrow aspiration and had positive culture for Brucella spp. Positive titres were found in 33 cases (97%) in Wright test, 23 cases (96%) in Coombs test, and 16 patients (72.7%) in 2ME (2-Mercaptoethanol) test. In one case, Wright and Coombs test titres were below 1:80 while Brucella spp. were isolated from blood at the same time. It is concluded, prolonged fever with joint involvement and organomegaly may increase possibility of infection with Brucella spp. Appropriate treatment regimen by more tolerable oral drugs, with a duration of at least 8 weeks, is recommended

High frequency of vancomycin resistant Enterococcus faecalis in children: an alarming concern

Introduction: Enterococcus spp. is considered as important etiological agents of nosocomial infections. However, a little is known about the epidemiology of vancomycin resistant Enterococcus faecalis (VREF). The aim of this study was to investigate the frequency of  VREF and detecting of two prevalent resistance genes (vanA, vanB) in pediatric population in an Iranian referral pediatric Hospital.Material and methods: During January 2013 to December 2013, 180 E. faecalis was isolated from clinical samples of hospitalized children at Children Medical Center Hospital, tertiary care and teaching hospital in Tehran, Iran. Antimicrobial testing was performed by Kirby-Bauer disk diffusion and E-test method according to Clinical Laboratories Standards Institute (CLSI). Two prevalent resistance genes (vanA, vanB) were investigated in VREF isolates.Results: Cephalosporin resistance was found in majority of E. faecalis isolates. There were no linezolid-resistant E. faecalis among all isolates. Teicoplanin resistance was observed in 13.8% of E. faecalis (n=25). MIC ≥32 µg/ml for vancomycin was found in 29 isolates (16%) and vanA gene was detected in 21 (72%) VREF strains, while vanB gene was not detected in any of these isolates. The mortality rate of all cases was 3.4% and 10% of patients with VREF infection died.Conclusion: This study reveals high rate of multidrug-resistant as well as vancomycin resistance in E. faecalis strains. Thus periodic surveillance of antibacterial susceptibilities is recommended to detect emerging resistance.

Candiduria in children: a first reportfrom an Iranian referral pediatric hospital

Candida spp. especially Candida albicans is considered as one of the most common cause of fungal infections. The aim of our study was to determine epidemiology of candiduria in children who were referred to an Iranian referral hospital. During May 2011 to February 2013, among 4813 urine culture positive, 209 candida spp. isolates (4.3%) was found. Forty-one percent of cadiduria infection was seen in patients between 1 month and 1 year, 24% in neonatant and 24% in patients 1 to 5 years. Cadiduria was mainly found in patients who had received more than 2 or 3 antibiotic during their hospitalization (37% and 24%, respectively). In our study, the highest frequency of cadiduria was seen in patients who had received more than 2 antibiotics and more than 3 antibiotics during their hospitalization; therefore, the strategic goals to opti- mize antimicrobial use including optimizing choice and duration of empiric therapy as well as monitoring and providing feedback regarding antibiotic resistance are recommended

Frequency of Chlamydia trachomatis in Women with Cervicitis in Tehran, Iran

Chlamydia trachomatis (CT) is the most common cause of bacterial sexually transmitted infection (STI) worldwide, but current data concerning the prevalence of CT among women in Iran is scarce. Data regarding the frequency of CT infection among Iranian women can help to justify the implementation of a national CT screening program that can reduce the high morbidity associated with sequelae of CT infections by treating infected women. Endocervical secretions from 123 married women (20–55 years) with cervicitis were tested by a PCR-EIA method using primers to amplify a CT-specific plasmid. The digoxigenin-labeled amplicon was measured by hybridization to a biotin-labeled probe and a strepavidin-coated plate, followed by an enzyme-linked colorimetric analysis. Overall frequency of CT infection among women was 17% (21/123). The range of CT frequency among various age groups was 12–25%. The 31–40-year-age group comprised the majority (49%) of CT positive samples, followed by 20–30 year group (33%). Although the 20-to-30-year-old women reported the highest frequency of STI history, they had the lowest relative frequency of CT infection (12%). There is a high frequency of CT infection among women with cervicitis in Tehran, Iran, thus indicating a necessity to implement a routine CT screening program in the major cities of Iran and possibly nationwide. Identification of CT-infected women may prevent its spread, and thereby reduce the high morbidity associated with CT infections among women in Iran

In vitro evaluation of the antimicrobial activity of nanosilver-mineral trioxide aggregate against frequent anaerobic oral pathogens by a membrane-enclosed immersion test

Background: Nanoparticles of silver (NanoAg) have been shown to control the growth of bacteria, but application of NanoAg in endodontics has not been evaluated. This in vitro study evaluates the antimicrobial activity of NanoAg to enhance the inhibitory effects of mineral trioxide aggregate (MTA). Methods: The antibacterial activities of NanoAg and NanoAg-MTA against four types of anaerobic pathogens were tested in vitro using (1) agar diffusion test (ADT) and (2) a newly devised membrane-enclosed immersion test (MEIT). Results: Both NanoAg and NanoAg-MTA inhibited the growth of all four test bacteria at 25 ppm concentration. MEIT analysis consistently showed that NanoAg enhanced the antimicrobial activity of MTA significantly, and the bacterial susceptibility to lower concentrations of NanoAg varied depending on the type of bacteria. Overall, NanoAg-MTA showed significant inhibitory effect which was time and dose dependent. Conclusions: Our data support that NanoAg can serve as an excellent MTA additive against anaerobic endodontic-periodontal pathogens with clinical applications for infection control in endodontics

Antimicrobial properties of poly (methyl methacrylate) acrylic resins incorporated with silicon dioxide and titanium dioxide nanoparticles on cariogenic bacteria

Aim: To assess the effects of adding nano-titanium dioxide (nano-TiO 2 ) and nano-silicon dioxide (nano-SiO 2 ) and their mixture to poly (methyl methacrylate) (PMMA) to induce antimicrobial activity in acrylic resins. Materials and Methods: Acrylic specimens in size of 20 mm × 20 mm × 1 mm of 0.5% and 1% of nano-TiO 2 (21 nm) and nano-SiO 2 (20 nm) and their mixture (TiO 2 /SiO 2 nanoparticles) (1:1 w/w) were prepared from the mixture of acrylic liquid containing nanoparticles and acrylic powder. To obtain 0.5% and 1% concentration, 0.02 g and 0.04 g of the nanoparticles was added to each milliliter of the acrylic monomer, respectively. Antimicrobial properties of six specimens of these preparations, as prepared, were assessed against planktonic Lactobacillus acidophilus and Streptococcus mutans at 0, 15, 30, 45, 60, 75, and 90 min follow-up by broth dilution assay. The specimens of each group were divided into three subgroups: Dark, daylight, or ultraviolet A (UVA). The percent of bacterial reduction is found out from the counts taken at each time point. Statistical Analysis: Data were analyzed using one-way analysis of variance and Tukey′s post hoc analysis. Results: Exposure to PMMA containing the nanoparticles reduced the bacterial count by 3.2-99%, depending on the nanoparticles, bacterial types, and light conditions. Planktonic cultures of S. mutans and L. acidophilus exposed to PMMA containing 1% of TiO 2 /SiO 2 nanoparticles showed a significant decrease (P 0.05) was observed in the counts of S. mutans and L. acidophilus in PMMA without the nanoparticles exposed to UVA. Conclusions: PMMA resins incorporated with TiO 2 /SiO 2 nanoparticles showed strong antimicrobial activity against the cariogenic bacteria

Cytomegalovirus infection and Guillain-Barré syndrome: A first case-control study in children in Iran

Objective: Guillain-Barré syndrome (GBS) is an immune-mediated disease of the peripheral nervous system which affects all age groups through the world. Although the pathogenesis and optimal treatment of GBS are still not completely established, one of the most common infectious diseases to trigger the syndrome is cytomegalovirus (CMV) infection. GBS following CMV infections is rarely reported in childhood and there is no data on GBS with antecedent CMV infection in children in Iran. The aim of this study was to evaluate the association of CMV infection and GBS in children in Iran. Materials & Methods: Case-control study design was used in 30 cases of Guillain-Barre syndrome, and 30 matched controls. All serum samples were tested for the presence of anti-CMV IgM and IgG antibodies using a commercially available ELISA (EUROIMMUN Medizinische, Germany).CMV viral DNA in the specimen was detected using polymerase chain reaction (PCR), (Cytomegalovirus PCR Detection Kit, CinnaGen company, Iran). Results: Anti–CMV immunoglobulin (Ig) G antibodies were detected in GBS patients and healthy controls in 97% and 93% of children, respectively. Anti-CMV IgM antibodies were demonstrated in 33% (n=10) of the healthy controls and 33% (n=10) of the children with GBS. The borderline level of anti-CMV IgM antibodies was found in 23% healthy controls (n=7) and 13% (n=4) in the children with GBS (p=0.57), respectively. None of the specimens from the both controls the cases with GBS was positive for CMV DNA by PCR. Conclusion: These data demonstrated the presence of anti-CMV antibodies in a majority of both patients with GBS and controls and no relation between CMV infection and GBS was observed. However, further studies with larges sample sizes are highly recommended