فهرست مطالب سیده سمیه جاسمی

Bachground and Aim: Acinetobacter baumannii is one of the important caues of nosocomial infection. Resistance to antibiotics specially carbapenem antibiotics is on the increase which can be an alarming sign for healthcare managers and personnel. The aim of this study was to investigate phentypic and genotypic characteristics of carbapenem resistant A. baumannii in the samples obtained from the patients in Imam Khomeini Hospital, Tehran city. Material and Methods: 100 strains were identified as A. baumannii by biochemical tests and molecular methods. Multiplex PCR method was used for identification of the genes of bla OXA family. Drug susceptibility pattern was determined by disk diffusion method. Among 100 isolates, 95(95%) were resistant to carbapenem antibiotics( imipenem and meropenem). PCR method was performed to identify blaOXA family genes. 9 isolates had blaOXA-51 gene while 38 had both blaOXA-51 and blaOXA-23 genes. 20 isolates were positive for blaOXA-51 and blaOXA-24 genes, 6 isolates had blaOXA-51 and blaOXA-58, and 8 isolates had blaOXA-51, blaOXA-24 and blaOXA-23 genes. 7 isolates were positive for blaOXA-51, blaOXA-23 and blaOXA-58. 4 isolates had blaOXA-51and blaOXA-24 and blaOXA-58 genes. We detected blaOXA-51and blaOXA-24 and blaOXA-23 and blaOXA-58 genes in three isolates. According to our results carbapenem resistant Acinetobacter baumannii strains spread increasingly among hospital units. We found that carbapenem resistant Acinetobacter strains with a high resistance rate are common in the hospitals in Iran

Bloodstream infections (BSIs) are an important cause of morbidity and mortality. The rates of antibiotic resistance among pathogens causing health care-associated infections are increasing, principally among Gram-negative organisms such as Pseudomonas, and Acinetobacter. The goal of this study was isolation Pseudomonas spp. and Acinetobacter spp. from blood specimens in patients hospitalized in Emam Khomeini hospital (Kermanshah) and subsequently determination susceptibility patterns of isolates. In this cross-sectional study 2382 blood samples collected from 2285 hospitalized patients. Blood specimens were inoculated in blood culture tubes media, and subsequently subculture performed on common microbiological media. The isolated Pseudomonas, and Acinetobacter were identified and confirmed by morphological and biochemical laboratory tests. Antimicrobial sensitivity test was performed by using the standard disc diffusion method according to CLSI (2012) recommendations. During present study 2382 blood samples were collected. 133 (5.6%) specimens were positive in bacterial culture. Acinetobacter, and Pseudomonas were isolated from 15 (11.2%) and 15 (11.2%) of positive blood cultures, respectively. The isolated Acinetobacter were most frequent resistant to cefixime (86.7%), ceftazidime (80.1%), cephalothin (73.4%), and co-trimoxazole (73.4%). The Pseudomonas isolates showed a high level of resistance to co-trimoxazole (86.7%), cefixime (86.7%), ceftriaxone (73.4%), cephalothin (73.4%), and ceftazidime (60%). In this research, drug-resistant Pseudomonas and Acinetobacter were identified in patient’s blood cultures. In the face of increasing antibiotic resistance, surveillance programs have become important in determination the species distribution and resistance patterns of pathogens causing bloodstream infection, and thus are providing the basis for appropriate empirical therapy of patients.

Citrobacter is a gram-negative, nonsporeforming, facultative anaerobic and motile bacillus within the family of Enterobacteriaceae and is ubiquitous in nature. This opportunistic pathogen causes a wide spectrum of infections. The aim of the present study was to examine the isolation of Citrobacter spp. from blood specimens in patients hospitalized in Kermanshah Imam Khomeini hospital and to determine the isolates sensitivity to antibiotics. This cross- sectional study was carried out on 2285 blood specimens collected from hospitalized patients between March 2012 and February 2012. In the beginning, the blood samples were inoculated in blood culture tubes media. The Citrobacter spp. isolates were identified and their identification was confirmed by means of morphological and biochemical laboratory tests. Drug sensitivity test was carried out according to CLSI (2011) recommendations through using the standard disc diffusion method. In this study Citrobacter spp. were isolated from 21 (15.8%) of 133 culture positive blood specimens collected from the hospitalized patients. The most effective antimicrobial agents against Citrobacter isolates were imipenem (90.4%), and amikacin (71.5%), respectively. The most frequent resistance observed was to cephalothin (76.2%), ciprofloxacin (76.2%), ceftazidime (66.6%) and co-trimoxazole (62%). Citrobacter isolates showed high resistance to betalactam antibiotics. Therefore, it is necessary that these drugs should only be administered to patients whose diagnostic isolates reveal sensitivity in vitro.

Hospital-acquired infections are a major challenge to patient. A range of gram-negative organisms are responsible for hospital-acquired infections, the Enterobacteriaceae family being the most commonly identified group overall. Infections by ESBL producers are associated with severe adverse clinical outcomes that have led to increased mortality, prolonged hospitalization, and rising medical costs. The aim of this study was to survey profile of antimicrobial susceptibility isolated microorganisms from hospitalized patients in PICU ward and detection of methicillin-resistant Staphylococcus aureus and ESBL-producing bacteria by phenotypic methods. In this study participants were patients hospitalized in PICU part of Bahrami Hospital, Tehran, with attention to involved organ. For isolation of bacteria from patient’s samples, culture performed on different selective and differential media. After confirmation of bacteria by biochemical tests, susceptibility testing was performed by disc diffusion method. Phenotypic detection of MRSA strains was performed using cefoxcitin disc. ESBL producing strains were detected by ceftazidime (CAZ) and ceftazidime/clavulanic acid (CAZ/CLA) discs. Among all isolated organisms from clinical samples, the most common isolated organisms were Escherichia coli (24 cases), Pseudomonas areoginosa (9 cases) and Staphylococcus aureus (8 cases), respectively. Among eight MRSA isolated strains from different clinical samples, six strains (75%) were MRSA. Among 52 isolated gram negative organisms, 5 strains (9/6%) were ESBL. Standard interventions to prevent the transmission of antimicrobial resistance in health care facilities include hand hygiene, using barrier precautions in the care of colonized and infected patients, using dedicated instruments and equipment for these patients. The colonized or infected patients should be isolated in single rooms, multibed rooms or areas reserved for such patients. Active surveillance screening is necessary to identify asymptomatically colonized patients who may serve as undetected reservoirs.