Maternal carriage and neonatal colonization of streptococcus agalactiae in Tabriz, Northwest Iran

Group B Streptococcus [GBS] is a major cause of severe systemic and local infections in newborns. This study was performed to evaluate the presence of GBS in pregnant women and their newborns in Tabriz, Iran. Vaginal specimens were collected from 965 women who were candidate for vaginal delivery for bacteriological study of group B streptococci. Several samples from various sites of the newborns' body [ear canal, nose, navel, and groin] were also obtained to study the colonization rate in newborns after vaginal delivery. Identification of GBS strains was accomplished by bacteriological and serological tests. During the study period, 327 microorganisms were isolated from vaginal specimens of pregnant women from which 5.2% were Streptococcus agalactiae. Serotypes of S. agalactiae strains in our study were Ia [17.6%], Ib [13.4%], II [14.2%], III [9.5%], IV [8.2%], V [19.5%] and nontypable [17.6%]. All of the newborns were followed up for eight weeks. Low carriage rate of GBS in vaginal canal of women in this area and probably lack of more virulent serotypes of GBS may explain the rarity of disease due to Streptococcus agalactiae in our region

[Detection of ethambutol-resistant mycobacterium tuberculosis strains by MAS-PCR method and comparison with proportion]

Ethambutol [EMB] is one of the first - line drugs used for anti-tubercular therapy but resistance to this medicine is developed in many parts of the world. EMB resistant strains commonly have embB mutations. Purpose of this research was detection of EMB-resistant Mycobactercium tuberculosis strains isolated from patients by MAS-PCR method and comparison with Proportion procedure. One hundred and twenty M. tuberculosis strains were isolated from patients with tulerculosis in Tabriz TB research center. Susceptibility testing to EMB was performed by the Proportion method. DNA was isolated from cultivated cells by SDS-proteinase K modified method. Isolated DNA was used as the template for PCR reaction. One hundred and sixteen strains were susceptible to EMB and 4 [3.33%] strains were resistant to EMB. All EMB resistant strains were multidrug-resistant. The MAS-PCR method was used to evaluate of mutation in the embB306 codon. Mutation was seen at the embB306 codon in all resistant strains to ethambutol. The results showed that MAS-PCR method can be used as a simple and rapid procedure for detecting EMB-resistance in Mycobacterium tuberculosis strains

[Frequency of enterohaemorrhagic Escherlchia coil isolated from patients with acute diarrhea in Tabriz hospitals]

Diarrhea is a major cause of morbidity in all age groups worldwide. Bacteria can cause 24% of infectious diarrhea which accounts for 70% mortality in affected children of <5 years old. Among the bacterial agents Salmonella spp, entero pathogenic E. coli, Campylobacter spp, Shigella spp and clostridia are the main causes of diarrhea. Escherichia coli O175 is an emerging cause of foodborne illness that presents with acute diarrhea. It transmits through the contaminated water, direct or indirect contact with animals and also through person to person contact. In addition to diarrhea, 2-7% of the patients infected with enterohemorrhagic E. coli [EHEC] will possibly develop haemolytic uremic syndrome [HUS] or acute renal failure. This study was conducted to determine the frequency of enteric pathogens with special reference to enterohaemorrhagic E. coli O157. A total of 1020 fecal specimens were collected from patients with acute diarrhea in Imam Khomeini and Children hospital of Tabriz. Direct examination was carried out for leukocytes, erythrocytes, parasite ova and trophozoites by wet mount preparation and the specimens also were cultured in selective and differential culture media for pathogenic bacteria. E. coli isolates were further typed using specific antisera and EHEC isolates were subjected to susceptibility testing against routinely used antibiotics. Entamoeba histolytica and Giardia lamblia were detected in 91[8.9%] and 51[5%] of cases. Pathogenic enteric bacteria were also isolated and recorded as E. coli O157 [n=6, 0.58%], E. coli O111 [n=15, 1.47%], E. coli O26 [n=13, 1.27%], Campylobacter jejuni [n=35, 3.4%], Salmonella spp. [n= 177 17.3%] and Shigella spp [9.5%]. All EHEC isolates were recovered from children <5 years old. In serological tests, 139 [13.5%] isolates of E. coli showed autoagglutination, which suggest their probable dependence to EAEC [entero aggregative E. coli]. Based on information collected from the EHEC positive patients' files, no sign of anemia or kidney disorder was detected. Entero pathogenic E. coli isolates are not usually tested in most of the routine diagnostic laboratories, so these medically important bacteria remain undiscovered, unless in an epidemic situation. Our findings of 3.3% enterohaemorrhagic E. coli and the presense of 0.58% E. coli O157 shows less frequency for these pathogenic bacteria and are in accordance with reports from other countries

[Nasal carriage rate of staphylococcus aureus in hospital personnel and inpatients and antibiotic pattern of isolated strains from nasal and clinical specimens in Tabriz]

Staphylococcus aureus is known as an important pathogen causing a variety of bacterial infections. Treatment of this bacterium with antibiotics has led to antibiotic-resistance, especially against methicillin [MRSA] and more recently rare resistance against vancomycin [VISA and VRSA]. MRSA strains compared to MSSA strains are resistant to most of the antibiotics in routine use. Aims of this study were to determine nasal carriage rate of S. aureus in hospital personnel and inpatients and to determine antibiotic-resistance patterns in the above mentioned isolates in the same hospitals. Staphylococcus aureus isolates collected from nose of 460 hospital personnel and inpatients [160 strains] and from clinical specimens [46 strains] in Imam Khomeini and Children medical centers in a 6 month period were studied in 2005. Antibiotic sensitivity of the collected strains were tested against 13 antibiotics used in routine treatment of S. aureus infections. Oxacillin agar was also used to screen for MRSA. Our results showed 34.7% nasal carrier rate for S. aureus in hospital personnel and patients studied. Seventy seven isolates were able to grow on oxacillin agar, indicating 37.4% MRSA strains. MRSA strains were also resistant to 4-11 antibiotics tested in this study, but MSSA strains, which were resistant to penicillin G [100%], mainly showed sensitivity to other test antibiotics. All of the MRSA and MSSA strains were sensitive to vancomycin. Generally, the resistance to methicillin was higher in clinical isolates compared to isolates recovered from nose [p< 0.001]. In this study, all of the test isolates were sensitive to vancomycin, which necessitates more caution in using this valuable antibiotic. Screening of hospital personnel and in-patients will better control the incidence of this important bacterium and use of molecular methods in detection of them, especially screening for mecA gene will provide some measures in control of hospital acquired infections