Evaluation of gallbladder contractility and Doppler findings in patients with irritable bowel syndrome; a case-control study.

BACKGROUND: Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder causing abdominal pain, altered bowel habits and bloating without structural issues. Gallbladder dysfunction may be linked to IBS due to disrupted cholecystokinin release. This study aims to assess gallbladder function and related hemodynamic parameters using Doppler ultrasound in IBS before and after meals. METHOD: In this case-control study, we investigated gallbladder function differences between constipation-predominant IBS (C-IBS) patients and healthy volunteers. Participants underwent ultrasonography to measure gallbladder parameters before and after consuming a predefined meal. Gallbladder volume, wall thickness and resistance index (RI) of cystic and superior mesenteric arteries (SMA) were assessed. Student t-test and paired t-test were used to compare case and control groups and pre- and post-meal data, respectively. RESULTS: A total of 34 people (18 C-IBS and 16 healthy control) were included. The mean (Standard deviation) of gallbladder fasting volume was measured 24.74 (8.85) and 29.73 (9.65) cubic millimeter for case and controls, respectively. Postprandial volume was 11.34 (5.66) and 16.9 (6.16) cubic millimeter for case and controls respectively. We observed a statistically significant difference in emptying fractions (EF) between groups (p value = 0.009). IBS patients had a smaller fasting SMA RI (p value = 0.016) but the fraction of change after meal was not significant (p value = 0.10). The cystic artery RI did not reach statistical significance between the fasting and post-meal values (p value = 0.067). CONCLUSION: IBS patients have a higher emptying fraction and lower change in SMA RI compared to healthy controls. Further studies with larger sample size, inclusion of patients with different coexisting conditions and subtypes of IBS and combining colon transit study with gallbladder ejection fraction evaluation can be used to further provide more meaning to this study.

Pilus-encoding islets in S. agalactiae and its association with antibacterial resistance and serotype distribution.

Group B Streptococcus (GBS) is a versatile organism which uses multiple virulence factors which bind to the surface of epithelial cells. Pili are one of virulence factors detected in recent years. A total of 90 isolates were collected from invasive and non-invasive isolates among adults throughout 2014-2015. Isolates were serotyped at molecular level based on capsular polysaccharide (cps) serotyping and analyzed for pilus island profiles, scpB gene, and hvgA gene presence. Isolates were subjected to antimicrobial susceptibility towards penicillin, tetracycline, erythromycin, clindamycin, moxifloxacin, levofloxacin, and vancomycin by disk diffusion method and MICs for erythromycin and clindamycin were determined by broth dilution methods. Overall, 4 serotypes were identified, serotype III (68.88%), V (20%), II (10%) and Ib (1.11%) and hvgA gene was detected in 7.7% (n = 7) of the isolates; all were serotype III/ST 17. All isolates were susceptible to penicillin and vancomycin, except one isolate which showed intermediate resistance to penicillin and other complete resistance to vancomycin. Isolates were resistant to tetracycline (98%), erythromycin (25%), clindamycin (22%), moxifloxacin (8%), and levofloxacin (6%). The scpB gene was detected in all isolates, while isolates harbored at least one PI, of which the PI-1+PI-2a was the most frequent combination observed. Our data show the presence of the relation between serotype or pilus genes among clinical isolates of Streptococcus agalactiae. These data are principal to help in designing prevention and treatment strategies for GBS infections in the region.

Streptococcus agalactiae clinical isolates in Northwest Iran: antibiotic susceptibility, molecular typing, and biofilm formation.

Background: Group B Streptococcus (S. agalactiae) is one of the colonizing bacteria in pregnant women which can be a causative agent of meningitis and neonatal sepsis. This organism has also been increasingly related to invasive infections in non-pregnant adults. Objective: In present study, we aimed to characterize the clonality of biofilm-producing S. agalactiae isolates from various sources from two different clinical laboratories in Tehran, Iran. Materials and Methods: S. agalactiae isolates were collected from community-acquired (CA) and hospital-acquired (HA) infections in pregnant and non-pregnant adults. The antimicrobial susceptibility patterns and biofilm formation ability were determined. In addition, pulse field gel electrophoresis (PFGE) was used to verify the clonal diversity of isolates. Results: Out of the 87 isolates, 15 (16.6%) formed biofilm. The antibiotic resistance rate was 98.85% for clindamycin, 98.85% for tetracycline, followed by 29.88% for erythromycin, 9.19% for moxifloxacin and 6.89% for levofloxacin. The PFGE patterns revealed a total of 16 different clusters consisting of 6 single types (STs). Conclusion: This study evaluated the biofilm formation of clinical S. agalactiae, which may be a step towards understanding its role in pathological processes. Biofilm formation was significant only in the hypervirulent ST-17 clone. Intraclonal spread of isolates indicates that a local lineage of isolates is responsible for infection by these bacteria.

Genotyping and Phylogenetic Analysis of Group B Streptococcus by Multiple Locus Variable Number Tandem Repeat Analysis in Iran.

BACKGROUND: Group B streptococcus (GBS), also known as Streptococcus agalactiae, is well known as a causative agent for neonatal invasive diseases; it is also a major pathogen in adults. Analytic epidemiology is required to monitor the clinical isolates of GBS. However, there is insufficient information on the genetic background of GBS in Iran, and this information is needed to guide and develop a GBS vaccine. MATERIALS AND METHODS: In total, 90 well-char - acterized GBS isolates were collected from April 2014 to August 2015. In this study, molecular typing was used to disclose a relationship between the multiple-locus variable number tandem repeat analysis (MLVA) types, serotyping, and pilus islands. The isolates were characterized by the types of capsular polysaccharides and pilus islands and were examined by MLVA to study the epidemiological relationship of isolates. RESULTS: The results indicate that there is a significant relationship between the distribution of serotypes and pilus island genes; GBS isolates were differentiated into 12 types by capsular polysaccharides and pilus islands analysis. The discriminatory power of an MLVA analysis was high based on the five most variable numbers of tandem repeat loci and 44 MLVA types that were identified. CONCLUSION: This study has provided useful insights into the genetic heterogeneity of GBS isolates in Tehran and Alborz, Iran. The extensive distribution of pilus islands in various serotypes and MLVA types throughout the GBS population refers to the advancement of the pilus-based GBS vaccines.

Comparison of multiple-locus variable-number tandem-repeat analysis with pulsed-field gel electrophoresis typing of carbapenemases producing Acinetobacter baumannii isolated from burn patients.

BACKGROUND: Acinetobacter baumannii is one of the important causes of nosocomial infection especially in burn patients. So, carbapenemase producing strains can make serious therapeutic problems. Molecular epidemiology studies play key role in decreasing the incidence of carbapenemase producing strains. METHODS: In this study, 50 carbapenem resistant A. baumannii isolates from burn patients were collected. Antibiotic susceptibility testing and PCR assay was performed for detection of blaVIM, blaIMP, blaOXA-23,blaOXA-48,blaNDM-1, blaSPM-1, blaOxa-51 and blaKPC genes. Molecular typing for carbapenemase producing strains were performed by PFGE and MLVA. RESULTS: According to the results of antibiotic susceptibility tests all of strains were XDR and 46 (92%) harbored carbapenemase genes. PFGE and MLVA results showed the presence of 11 and 5 dominant clonal types respectively. CONCLUSION: The results of this study were showed the presence of certain clonal groups in two different wards of hospital indicating the spread of carbapenemase producing A. baumannii. On the other hand, the results showed the more discriminating power for PFGE.

The Dominance of Pilus Islet 1 in Pneumococcal Isolates Collected From Patients and Healthy Individuals.

BACKGROUND: Pili in Streptococcus pneumoniae have been shown to be one of the adherence factors for epithelial cells in the human upper respiratory tract. Two types of pilus-like structures (pilus islet-1 and pilus islet-2) have been distinguished in S. pneumoniae. OBJECTIVES: To investigate the presence of pilus islet-1 (PI-1) in S. pneumoniae and the correlation between our isolates. MATERIALS AND METHODS: In this study, 162 S. pneumoniae isolates were collected from clinical specimens, and normal flora were also examined for the distribution of PI-1 using the presence of the rlrA and rrgC genes as markers for this islet and sipA as an indicator of pilus islet-2 (PI-2). BOX-PCR analyses were performed to determine the genetic relationship between isolates. RESULTS: The results confirmed the presence of rlrA and rrgC genes in both clinical (n = 39) and normal flora (n = 26) isolates. The minimal inhibitory concentration results revealed that the rate of resistance of these isolates to the three antibiotics tested ranged from 26% for penicillin to 46% for erythromycin and tetracycline. Furthermore, 12% of the isolates were resistant to all three antibiotics. Strain typing using repetitive element BOX-PCR analysis among the 65 isolates identified 8 different band patterns. CONCLUSIONS: Our results indicated that the dissemination of PI-1 was widespread in S. pneumoniae isolates, although no PI-2 isolates were detected. Furthermore, the frequency of rlrA and rrgC of clinical isolates was significantly more than that of normal flora isolates.

Detection of integrons and Staphylococcal Cassette Chromosome (SCCmec) types in Staphylococcus aureus isolated from burn and non-burn patients.

BACKGROUND: Methicillin Resistant Staphylococcus aureus (MRSA) strains have been recognized as an important reason of infections in health care units. Integrons role in antibiotic resistance box gene transfer has been well recognized which are found in Gram positive bacteria. OBJECTIVE: The aim of this study was analyzed of SCCmec typing and determine of integron classes in burn and non-burn specimens. METHODOLOGY: A total of 110 S. aureus strains were isolated from burn and non-burn patients. Antimicrobial susceptibility testing, detection of mecA gene, various SCCmec types and integrons classes were analyzed. RESULTS: In antimicrobial susceptibility test in burn patients, resistant to both gentamicin and oxacilin and in non-burn patients resistance to oxacilin and cefepime showed the highest ratio In PCR molecular test (80%) and (52.7%) of strains harbored the mecA gene. Therefore five different SCCmec types were recognized among our studied strains. Subsequently, integron class I was evaluated as (94.5%) in burn and (12.7%) in non-burn isolates by the multiplex PCR method. CONCLUSION: Albeit MRSA strains have the hospital reservoir so may cause serious treats for hospitalized and non-hospitalized patients, hence clinical decision for prevention and treatment may develop due to, mecA gene, SCCmec elements and integrons detection in health care units.