Archives of Clinical Infectious Diseases
Volume:7 Issue: 1, Jan 2012

Acinetobacter baumannii is an opportunistic pathogen that causes serious infections in humans bycolonization of medical devices. The capacity of this pathogen to persist in hospital settings could be due to its ability to form biofilms. In the present study we evaluated the effect of antibodies against one of surface components of A.baumannii on in vitro biofilm formation. The 1113 bp fragment of Bap (biofilm associate protein)gene from A. baumannii genome was amplified and cloned. The recombinant protein was expressed and purified and used to raise antibodies in mice.Antibody titer was evaluated by ELISA. In vitro biofilm inhibition was evaluated using the mice sera. Injection of Bap subunit resulted in high titers of antibody. Immunized mice serum had significant (P<0.001) inhibitory effect on biofilm formation. In vitro inhibition of biofilm formation by A. baumannii was studied at 1:50 concentrations of immunized and unimmunized mice sera. Immunized mice serum had significant (P <0.001)inhibitory effect on biofilm formation Adsorption of antibodies to Bap might interfere with bacterial adhesion to the surface. These antibodies were found to be potent biofilm inhibitors.

Microscopy of Giemsa-stained thick and thin peripheral blood smear (PBS) remains as the standard laboratory method for the diagnosis of symptomatic malaria. This study was done to compare PBS with polymerase chain reaction (PCR) method for detecting asymptomatic malaria parasitemia.Patients and Blood samples were collected from 900 asymptomatic school children between 7-11 years old in one of the provinces in the South of Iran. All 900 students were negative for plasmodium vivax and plasmodium falciparum by PBS. PCR method detected DNA of P. vivax in 10 blood samples (1.1%). Specificity and negative predictive value of PCR method was respectively 98.89% (95%CI: 98.0-99.5%), 100% (95%CI: 99.6-100%) compared to PBS as the gold standard method. As there was no positive case by PBS method, calculation of sensitivity, positive predictive value and likelihood ratios of the PCR method was not possible. In comparison to PBS, expensive and prolongation PCR method is not suitable and cost effective for identification of malaria infection in asymptomatic.

Pseudomonas aeruginosa is an opportunistic pathogen that infects hospitalized, burned and immunosuppressed patients. The main aim of the present study was to develop a vaccination strategy based on recombinant flagellin type A (r-fla-A) that would enhance the protective response against P. aeruginosa in the burn wound sepsis model. After the preparation of type A r-flagellin, a specific polyclonal IgG was produced in rabbit.After immediate post-burn and post-challenge, mortality rate was screened in the mice treated with anti r-fla-A IgG, and inbred mice were also immunized with r-fla-A in separate groups. After final booster, vaccinated mice were burned and challenged with P. aeruginosa. The functional activity of anti r-flagellin antisera was determined by opsonophagocytic killing test. To evaluate the humoral immune response, sera were analyzed by ELISA for its total antibody. In vivo administration of r-fla-A afforded a remarkable improvement in the survival of mice challenged with homologous strain (PAK) in the burn wound infection (83.3% vs. 0% in control; P < 0.005). The antibodies generated against the r-fla-A achieved 25% survival in immunized mice that were infected with heterologous strain PAO1. The anti r-fla-A IgG afforded a significant improvement in survival of mice infected by homologous strain PAK from 16.6% to 75%; In contrast, this antiserum achieved 33.3% survival following challenge with heterologous strain PAO1 (compared to control IgG). Anti r-flagellin antibody promoted phagocytosis of the homologous strain and decreased the killing of heterologous strain (53.1% and 17.4% respectively vs. 3.7% in the control group; P < 0.001). Flagellin also induced a high level humoral immune response in the immunized burned and challenged mice. We concluded that immunization with r-fla-A and anti r-fla-A would protect burned mice against lethal P. aeruginosa challenge.

Spinal osteomyelitis is an uncommon cause of back pain but it has potential to compromise nervous system and even death may occur if it is not treated effectively. We compared the underlying diseases, clinical, and complications among patients with pyogenic (PVO), brucellar (BVO), and tuberculous vertebral osteomyelitis (TVO).Patients and In this descriptive-comparative study, all patients older than 1 year who were hospitalized at Rasoul-e-Akram Hospital from 1999 to 2009 with a confirmed diagnosis of VO were included. The diagnosis of VO was confirmed in the presence of compatible clinical features, vertebral CT scan or MRI. Etiological diagnosis of VO was defined when the microorganism was isolated from blood culture, bone biopsy, paravertebral abscess aspiration; typical histopathological pattern of tuberculosis (caseating granuloma) or malignancy in bone biopsy; Wright’s orserum agglutination test  1/80 or 2ME  1/40 according to the national guidelines. Analytical statistics such as the chi-square and t test were used to find correlation and relationships among the variables. P< 0.05 was considered to indicate statistical significance. A total number of 87 patients studied. There were 62 (71.26%) males and 25 28.73%) females. Thirty-eight (43.67%) patients had PVO, 26 (29.88%) had TVO, 18 (20.68%) had BVO, 3 (3.4%) had malignant disorder with metastasis to bone, and the remaining 2 (2.29%) cases had fungal VO. Fever and back pain were the most common symptoms in PVO (12), but in TVO the most common symptom was back pain. DM and previous bone spinal surgery were the most common underlying diseases in PVO patients (P=0.000). Paravertebral abscess was reported in 6 (23.7%) patients with TVO and 6 patients (15.78%) with PVO, but no such complication was noted in BVO group. There are significant differences between VO by different microorganisms that help physician to start empirical medical treatment while waiting to definite diagnosis by blood culture, culture from paravertebral abscess, serology and bone biopsy.

To investigate association between nosocomial infection, blood products transfusion and microorganisms responsible in patients who hospitalized at ICU (intensive care unit). Patients and In this prospective study, 217 patients who were admitted to the ICU of Taleghani Hospital between August 2010 and August 2011 were included. Nosocomial infections were defined using the contacts for disease control and development national nosocomial infections surveillance definitions. Overall, site specific nosocomial infections rates, blood units received, attributable mortality rate and excess length of hospital stay and other variable were considered. The overall nosocomial infection rate was 24.9% (54 patients). The most common type of nosocomial infection was respiratory tract infections (6.5%, 14) with an attributable mortality rate of 3.7%. In patients who received blood products, 26.6% (37) acquired nosocomial infections. Despite the high percentage of blood transfusion in the hospital, no statistically significant relationship was observed between nosocomial infections and blood product transfusion. No significance relation was found between NIs and blood transfusion, but was observed between FFP transfusion and NIs. It’s emphasized the need for careful disinfection for FFP transfusion in ears that serve immunosuppressed individual, such as pediatric patients.

Sepsis is one of the most important causes of mortality in trauma patients. Sometimes its diagnosis could be difficult, especially at early stages. It is clear that early diagnosis of sepsis, especially with serum markers, may decrease the rate of death in trauma patients. Investigation to find a rapid as well as accurate serum marker indicative of sepsis seems necessary. Seum antithrombin III (AT III) level may predict sepsis occurrence in multitrauma patients. From January 2010 to June 2010, 50 patients with multi-trauma injuries were enrolled in our study. All of them were hospitalized in the intensive care unit (ICU) of neurosurgery department, Imam Reza university hospital, Tabriz University of Medical Sciences, Tabriz, Iran. Twenty-four patients demonstrated sepsis manifestations (sepsis group), but 26 patients did not (non-sepsis group). During ICU stay, blood levels of AT III were measured on days 0, 3, 7. Then, the obtained values were compared between the two groups. Mean (±standard deviation, SD) serum AT III level upon hospitalization was 95.00 ±15.55) g/ml in sepsis group and 106.28 (±17.45) g/ml in non-sepsis group (P= 0.02). Serum AT III level variations during an inter-group study was not significant in non-sepsis group (P= 0.74), but it was statistically significant in sepsis group (P< 0.001). Serum AT III level variations were studied in patients with and without sepsis at different time points with repeated measured ANOVA test. This analysis showed that the variations were statically significant in both groups (P< 0.001). Serum AT III level was lower in trauma patients who developed sepsis. Inter group study showed that serum AT III level variations were statistically significant in the sepsis group but not in the non sepsis patients. So AT III serum level measurement may predict the occurrence of sepsis in traumatic patients earlier.

All organ systems may be affected by tuberculosis (TB) but tuberculosis arthritis is responsible for approximately 1%of TB patients. Weight bearing joints such as hips and knees are most commonly affected; whereas involvement of sternoclavicular joint with tuberculosis is a very rare disease. In this case report we present a 63-year old woman with tuberculosis of the sternoclavicular joint. Her chief complaint was left shoulder pain and swelling over the left sternoclavicular region. It was diagnosed clinically and confirmed by histological results of the needle biopsy of tissue specimens. The diagnosis of tuberculous arthritis should be considered in any patient with unexplained shoulder pain and swelling in sternoclavicular joint in an endemic region for tuberculosis.