Improvement of semen parameters after antibiotic therapy in asymptomatic infertile men infected with Mycoplasma genitalium.

OBJECTIVES: To elucidate the association between asymptomatic infections caused by Mycoplasma genitalium and male infertility, and evaluate the role of antibiotic therapy in treatment of this failure. METHODS: A total of 165 infertile males having abnormal semen parameters (study group) and 165 healthy fertile men (control group) were included. Semen samples were taken from all participants and after analyzing for semen parameters, undergone real-time PCR, microbial culture, and reactive oxygen species (ROS), as well as total antioxidant capacity (TAC) assays. Infected individuals of study group were treated with antibiotic. One month after the treatment completion, second semen samples were taken and subjected to all the tests mentioned. The data were analyzed using SPSS statistical software, version 22.0. RESULTS: The frequency of M. genitalium was significantly higher in the infertile men compared with the fertile ones (9.7% vs. 1.2%; p = 0.001). Mean cycle threshold (C t) value was lower in infected infertile than infected fertile men (p < 0.001). All semen parameters, except volume, pH, and viscosity, were improved (p < 0.05), most of which reached their normal range; leukocytes in seminal fluid decreased (p = 0.02), the level of TAC was elevated (p = 0.002), and ROS level as well as ROS/TAC ratio reduced after antibiotic treatment (p = 0.03). Wives of seven infected infertile men (43.8%) became pregnant 4 months after the treatment completion. CONCLUSIONS: Asymptomatic infection caused by M. genitalium is correlated with male infertility and antibiotic therapy can improve the semen quality and be used to treat male infertility.

Determination of carbapenem resistance mechanism in clinical isolates of Pseudomonas aeruginosa isolated from burn patients, in Tehran, Iran.

Carbapenems are the most important therapeutic options that effect against serious infections caused by multidrug resistant Pseudomonas aeruginosa (MDR-PA) isolates. Carbapenems resistant isolates of P. aeruginosa are increasing worldwide. The aim of this study was to determine the carbapenem resistance mechanisms in clinical P. aeruginosa isolates from burn patients, in Tehran, Iran. A total of 53 non-duplicated isolates of carbapenem-resistant P. aeruginosa were collected from burn patients. The presence of carbapenemase genes were determined by PCR. AmpC overproducer isolates were detected by phenotypic method. The mutation and transcription level of oprD were determined by PCR-sequencing and quantitative Real-time PCR (RT-PCR), respectively. Twenty-seven (50.9%) isolates were positive for carbapenemase (blaVIM=25 and blaIMP=2) and showed high-level resistance to imipenem and meropenem. Twenty-eight isolates were AmpC overproducers. All isolates had a mutation in the oprD gene and down-regulation of oprD was found in 56.6% of MDR-PA isolates. Although the presence of carbapenemase is the common mechanism of resistant to carbapenem, but carbapenem resistance was found by oprD mutation-driven and the AmpC overproducing isolates in Tehran, Iran.

Asymptomatic Infection With Mycoplasma hominis Negatively Affects Semen Parameters and Leads to Male Infertility as Confirmed by Improved Semen Parameters After Antibiotic Treatment.

OBJECTIVE: To elucidate the association between asymptomatic infections caused by Mycoplasma hominis and male infertility and to evaluate the role of antibiotic therapy in the treatment of this failure. MATERIALS AND METHODS: A total of 165 infertile men having abnormal semen parameters (study group) as well as 165 healthy fertile men (control group) were included in this study. Semen samples were taken from all participants and, after analyzing for semen parameters, real-time polymerase chain reaction, microbial culture, and reactive oxygen species (ROS) as well as total antioxidant capacity (TAC) assays were performed. Infected individuals of the study group were treated with antibiotic. One month after the treatment completion, second semen samples were taken and all the tests mentioned were performed. The data were analyzed using SPSS statistical software, version 22.0. RESULTS: The frequency of M. hominis was significantly higher in the infertile men compared with the fertile ones (14.5% vs 3.6%, P = .001). The mean cycle threshold (Ct) value was lower in infected infertile men than in infected fertile men (P < .001). All semen parameters, except volume, pH, and viscosity, were improved (P < .05), most of which reached their normal range; leukocytes in seminal fluid were eliminated (P = .04); the level of TAC elevated (P < .001); and the ROS level as well as the ROS-to-TAC ratio reduced after antibiotic treatment (P = .02). Moreover, wives of 14 infected infertile men (58.3%) became pregnant 4 months after the treatment completion. CONCLUSION: Our data suggest that asymptomatic infection caused by M. hominis is correlated with male infertility and antibiotic therapy can improve the semen quality and fairly treat the male infertility.

Characterization of virulence factors, antimicrobial resistance pattern and clonal complexes of group B streptococci isolated from neonates.

Between January and December 2013, swab samples were taken for the throat and external ear canals of 1037 newborns for screening of Group B Streptococcus (GBS or S. agalactiae). Isolates were analyzed form Multilocus sequence typing (MLST), capsular type, virulence genes and antibiotic susceptibility. The MLST analysis of 19 GBS isolates showed 8 sequence types (STs). Overall the most common STs were ST19 and ST28. Other STs were ST1, ST4, ST8, ST12, ST335 and ST734 (a new ST). The most common clonal complexes (CCs) were CC19 (68.4%) and CC10 (21%). The scpB, hlyB and bca virulence genes were detected in all STS, while the bac gene was predominant in ST12 with capsular type (CT) Ib. The IS1548 and the rib genes were particularly prevalent in CTIII and were detected in isolates belong to ST19, ST335 and ST734 and were grouped in CC19. All isolates were susceptible to penicillin, vancomycin, linezolid and quinupristin-dalfopristin. Resistance to tetracycline was observed in all 19 (100%) strains and was correlated with presence of the tetM gene except for one isolate with ST12. All the ST8 and ST12 isolates were resistant to macrolide carrying two resistance genes; the ermTR and the ermB, respectively. The results of this study showed that the CC19 was a major clone in the neonatal intensive care unit (NICU) of Imam Khomeini hospital which can cause severe infections in susceptible neonates (particularly in premature infants). As a result, an intensive infection control policy is needed to prevent the spread of this clone.

Prevalence of Urogenital Mycoplasmas in Iran and Their Effects on Fertility Potential: A Systematic Review and Meta-Analysis.

BACKGROUND: Urogenital mycoplasmas are potentially pathogenic species causing genitourinary tract infections that may be initially asymptomatic but can progress and lead to severe complications and threaten reproductive health. However, the overall prevalence rate of this bacterium and its probable impacts on fertility potential have yet to be determined. METHODS: We searched both English and Persian electronic databases using key words such as "Mycoplasma," "Ureaplasma," "M. hominis," "M. genitalium," "U. urealyticum," "U. parvum," "prevalence," and "Iran". Finally, after some exclusion, 29 studies from different regions of Iran were included in our study, and a meta-analysis was performed on collected data. RESULTS: Urogenital mycoplasmas prevalence for women and men was high and ranged from 2%-40.5% and 2%-44.3%, respectively. The pooled prevalence in the male population was 11.1% (95% CI, 7.4%-16.4%) and in female was 12.8% (95% CI, 9.8%-16.5%). The prevalence of these bacteria was significantly higher in infertile men compared with that in fertile men. A high level of heterogeneity was observed for both men (I(2) = 92.4%; P<0.001) and women (I(2) = 93.3%; P<0.001). Some evidence for publication bias was observed in both men [Egger's test (two-tailed P=0.0007), and Begg's test (two-tailed P=0.0151)] and women [Egger's test (two-tailed P=0.0006), and Begg's test (two-tailed P=0.0086)] analysis. CONCLUSION: Since urogenital mycoplasmas may play a role in male infertility, screening strategies, particularly for asymptomatic individuals, and treatment of infected ones, which can reduce consequent complications, looks to be necessary.

Association of Chlamydia trachomatis with infertility and clinical manifestations: a systematic review and meta-analysis of case-control studies.

Background Chlamydia trachomatis is one of the sexually transmitted pathogens causing reproductive health-threatening diseases worldwide. However, its role in infertility, particularly in asymptomatic individuals, is not yet definitely determined. Methods For the study, electronic databases were searched using the following keywords; 'Chlamydia trachomatis', 'prevalence', 'frequency', 'fertile', 'infertile', 'case', 'control', 'symptomatic' and 'asymptomatic'. Finally, after some exclusions, 34 studies (19 fertile-infertile and 15 symptomatic-asymptomatic) from different countries were included in the study and meta-analysis was performed on the data collected. Results Odds ratios (ORs) for urogenital C. trachomatis prevalence in males in the fertile-infertile group, for infertile and fertile individuals, ranged from 1.3-3.7 and in females from 1.04-4.8, and the overall OR for both genders was 2.2 (95% CI). In the symptomatic-asymptomatic group, the overall OR in males and females was 4.9 (95% CI = 1.1-21.7) and 3.3 (95% CI = 1.7-6.3), respectively. In all of the analyses, there were high levels of heterogeneity (I(2) >50%, p-value <0.05) and, except for the females in the symptomatic-asymptomatic group, neither Egger's tests nor Begg's tests were statistically significant for publication bias. Conclusions C. trachomatis can impact on the potential for fertility and cause clinical manifestations and complications in both males and females. Thus, national programmes for adequate diagnosis, screening and treatment of infected individuals, particularly asymptomatic ones, seem to be necessary.

Assessment and comparison of probiotic potential of four Lactobacillus species isolated from feces samples of Iranian infants.

The probiotic potential of Lactobacillus species isolated from infant feces was investigated. For this study, the antibiotic susceptibility, tolerance in gut-related conditions, antimicrobial activity, and ability to adhere to a human colorectal adenocarcinoma cell line (Caco-2 cells) of four common Lactobacillus species (Lactobacillus paracasei [n = 15], Lactobacillus rhamnosus [n = 45], Lactobacillus gasseri [n = 20] and Lactobacillus fermentum [n = 18]) were assessed. Most isolates that which were sensitive to imipenem, ampicillin, gentamycin, erythromycin and tetracycline were selected for other tests. L. gasseri isolates had the greatest sensitivity to gastric and intestinal fluids (<10% viability). L. fermentum (FH5, FH13 and FH18) had the highest adhesion to Caco-2 cells. The lowest antibacterial activity against pathogenic bacteria was shown by L. gasseri strains in spot tests. Furthermore, non-adjusted cell-free culture supernatants with low pH had greater antimicrobial activity, which was related to organic acid. The results showed that some isolates of L. rhamnosus and L. fermentum are suitable for use as a probiotic.

Prevalence of genital Chlamydia trachomatis in Iran: a systematic review and meta-analysis.

OBJECTIVE: To determine the overall prevalence of Chlamydia trachomatis in Iranian males and females and to find out the effect of this bacterium on fertility potential and its association with urogenital symptoms. METHODS: We searched both English and Persian electronic databases using keywords 'Chlamydia', 'Chlamydia trachomatis', 'prevalence', 'incidence', 'frequency', 'epidemiology' and 'Iran'. Finally, after some exclusion, 34 studies from different regions of Iran were included in our study, and a meta-analysis was performed to determine pooled prevalence estimates for each group. RESULTS: C. trachomatis prevalence for women and men was high and ranged from 0 to 32.7% and 0 to 23.3%, respectively (95% CI). The pooled prevalence of the bacterium in the female population was 12.3% (95% CI: 10.6-14.2%) and in men was 10.9% (95% CI: 7.6-15.4%). A high level of heterogeneity was seen for both men (I(2) = 77.4%; P < 0.001) and women (I(2) = 77.5%; P < 0.001); but in men and not in women, some evidence for publication bias was observed [Egger's test (two-tailed P = 0.013); Begg's test (two-tailed P = 0.025)]. In females analysis of symptomatic/infertile group with asymptomatic/fertile group in females, the overall OR was above 1 and the overall P-value was below zero. CONCLUSIONS: This bacterium may play a role in female infertility or be associated with clinical manifestations; thus, planning national programmes for adequate diagnosis of genital infections caused by this pathogen is necessary. Furthermore, screening strategies, particularly for asymptomatic individuals, and treatment of infected people can reduce consequent complications.

Virulence profiling and genetic relatedness of Shiga toxin-producing Escherichia coli isolated from humans and ruminants.

In the present study the occurrence, genotypic characteristics and relatedness of Shiga toxin-producing Escherichia coli (STEC) isolated from 235 fecal samples of diarrheic children (n=75), sheep (n=80), and cattle (n=80) were investigated. Overall, STEC was found in 4%, 61.2%, and 18.7% of diarrheic children, sheep and cattle, respectively. Three of the four STEC isolates from diarrheic children yielded the stx1/ehly profile. The predominant virulence profile of sheep isolates was stx1/ehly (85.2%), but cattle isolates were heterogeneous. Genetic relatedness and diversity of 36 selected isolates were analyzed by enterobacterial repetitive consensus sequences fingerprinting (ERIC) and phylogrouping. In total, 19 ERIC-types were observed in humans (n=2), sheep (n=5), and cattle (n=12) isolates. The majority of the sheep STEC were assigned into B1 phylogroup (83.3%), but cattle isolates belonged to different phylogroups with B1 predominance. Three human STEC isolates had the major characteristics of sheep isolates but revealed distinct fingerprint. These findings indicate that cattle can potentially carry a diverse group of STEC strains.

ISPpu22, a novel insertion sequence in the oprD porin gene of a carbapenem-resistant Pseudomonas aeruginosa isolate from a burn patient in Tehran, Iran.

BACKGROUND AND OBJECTIVES: The oprD mutation and AmpC overproduction are the main mechanisms of intrinsic resistance to carbapenems such as imipenem and meropenem in Pseudomonas aeruginosa. MATERIALS AND METHODS: In this study, we investigated intrinsic resistance to carbapenems including mutation of oprD and AmpC overproduction in a carbapenem-resistant P. aeruginosa isolated from a burn patient by phenotypic and molecular methods. RESULTS: In our study, the carbapenem-resistant P. aeruginosa isolate was resistant to imipenem, meropenem, cefepime, gentamicin, ceftriaxone, carbenicillin, aztreonam and ciprofloxacin but was susceptible to ceftazidime and polymyxin B. The minimum inhibitory concentrations (MICs) against imipenem, meropenem and ceftazidime were 64 µg/ml, 16 µg/ml and 2µg/ml, respectively. The isolate was ESBLs and AmpC overproducer. No carbapenemase activity was detected by Modified Hodge test (MHT). This isolate was carrying only bla OXA-10 . PCR amplification and sequencing of oprD performed on isolate resulted in PCR product of 2647bp. Sequence analysis of the 2647bp product revealed insertion of a sequence of 1232 bp at position 8 in coding region of oprD. CONCLUSION: According to the results of this study, oprD mutation and AmpC overproduction can cause the main mechanism of resistance of P. aeruginosa to carbapenems.

Virulence factors, antimicrobial susceptibility and molecular characterization of Streptococcus agalactiae isolated from pregnant women.

Forty-one Streptococcus agalactiae isolates collected from pregnant women at 35-37 weeks of gestation were analysed for their capsular types, antimicrobial resistance determinants, distribution of virulence factors and genetic relatedness using PCR and multiplex PCR. Capsular type III was predominant (65.8%), followed by capsular type II (14.6%), Ib (7.3%), and V(4.9%). All isolates were susceptible to penicillin, vancomycin, linezolid and quinupristin-dalfopristin. Resistance to tetracycline, erythromycin and clindamycin were found in 97.6%, 24.4%, and 14.6% of isolates, respectively. The most common antimicrobial resistance gene was tetM found in 97.6% of the isolates followed by ermTR and ermB found in 12% and 7.3% of isolates, respectively. The most common virulence gene was hly (100%), followed by scpB (97.6%), bca (97.6%), rib (53.65%) and bac (4.9%). The insertion sequence IS1548 was found in 63.4% of isolates. By multi locus variable number of tandem repeat analysis (MLVA) typing, 30 different allelic profiles or MLVA types (MTs) were identified. The most frequent was the MT1 (5/41, 12.2%) and followed by MT2 (4/41, 9.75%). Our data revealed that population structure of these isolates is highly diverse and indicates different MLVA types.

The effect of hydro alcoholic extract of seven plants on cariogenic bacteria--an in vitro evaluation.

AIM: To compare the antibacterial effect of hydro alcoholic extract of Salvia officinalis, Pimpinella anisum, Satureja hortensis, Rhus coriaria, Carum copticum, Mentha longifolia, Achillea millefolium against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus through two in vitro methods. METHODS: In this experimental study, hydro-alcoholic extracts have been prepared from the shoot of Salvia officinalis, Satureja hortensis, Mentha longifolia and Achillea millefolium, the seed of Pimpinella anisum and Carum copticum and the fruit of Rhus coriaria with maceration method. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated with broth macrodilution and agar diffusion methods. RESULTS: In Broth macrodilution method MIC (Minimum Inhibitory Concentration) of Pimpinella anisum, Salvia officinalis, Mentha longifolia, Achillea millefolium, Satureja hortensis, Carum copticum and Rhus coriaria for Streptococcus mutans were respectively 12.5, 6.25, 12.5, 50, 50, 12.5 and 50 µg/ml, for Lactobacillus rhamnosus 12.5, 1.56, 3.12, 12.5, 6.25, 6.25 and 6.25 µg/ml and for Actinomyces viscosus 50, 12.5, 100, 50, 100, 25 and 25 µg/ml. In Agar diffusion method Pimpinella anisum, Salvia officinalis and Rhus coriaria against Streptococcus mutans, Pimpinella anisum, Carum copticum and Rhus coriaria against Lactobacillus rhamnosus and Mentha longifolia, Rhus coriaria and Carum copticum against Actinomyces viscosus had antibacterial effects. CONCLUSION: All seven extracts had growth inhibitory effects on all three bacteria. Salvia officinalis had the greatest inhibitory effect on growth of all three bacteria. All of the extracts except Carum copticum had bactericidal effect in the range of concentration. By agar diffusion method Rhus coriaria had antibacterial effect against all three cariogenic bacteria.

Determination of extended spectrum beta-lactamases, metallo-beta-lactamases and AmpC-beta-lactamases among carbapenem resistant Pseudomonas aeruginosa isolated from burn patients.

BACKGROUND: Pseudomonas aeruginosa is an important cause of morbidity and mortality in patients with burns. METHOD: A total of 214 nonduplicated burn wound isolates of P. aeruginosa were recovered from burn patients. Identification of carbapenem resistant isolates and their antimicrobial susceptibility pattern was carried out using the phenotypic methods. The presence of genes encoding extended spectrum beta-lactamases (ESBLs) and metallo-beta-lactamases (MBLs) enzymes were determined by PCR. The genetic relationships between carbapenem resistant isolates were determined by Random Amplified Polymorphic DNA (RAPD)-PCR. RESULTS: Of 214 investigated P. aeruginosa isolates, 100 (46.7%) were carbapenem resistant. All carbapenem resistant P. aeruginosa were resistant to imipenem, meropenem, ertapenem, carbenicillin, aztreonam, gentamicin and ciprofloxacin but susceptible to polymyxin B. Among 100 carbapenem resistant P. aeruginosa isolates, 3%, 65% and 52% were identified as ESBLs, carbapenemase and AmpC overproduction positive isolates respectively. The most prevalent ESBLs and MBLs genes included blaOXA-10 (97%), blaTEM (61%), blaVIM (55%), blaPER (13%), blaIMP (3%) and blaAIM (1%). RAPD analysis yielded 13 distinct profiles among 92 isolates. A dominant RAPD type was designated as A that consisting of 80 isolates. CONCLUSION: This is the first report of Adelaide IMipenmase (AIM) MBLs producing P. aeruginosa from Iran and also of the high prevalence of AmpC overproduction isolates. According to the results of current study, P. aeruginosa isolates producing OXA-10, TEM, VIM, PER and IMP beta-lactamases are frequent and the population structures of these isolates are highly similar.

High Incidence of Macrolide and Tetracycline Resistance among Streptococcus Agalactiae Strains Isolated from Clinical Samples in Tehran, Iran.

BACKGROUND: Streptococcus agalactiae or Group B Streptococci (GBS) is an important bacterial pathogen that causes a wide range of infections including neonatal sepsis, meningitis, pneumonia and soft tissue or urinary tract infections. MATERIAL AND METHODS: One hundred and fifteen isolates of Streptococcus agalactiae collected from urine specimens of patients attending a hospital in Tehran. All isolates were screened for their capsular types and genes encoding resistance to the macrolide and tetracycline antibiotics by PCR and multiplex PCR-based methods. RESULTS: Most of isolates belonged to capsular types III (49%), V (19%), II (16%), and Ib (6%). Twelve isolates (10%) were nontypable. All isolates were susceptible to penicillin and Quinupristin-dalfopristin, but were resistant to clindamycin (35%), chloramphenicol (45%), erythromycin (35%), linezolid (1%) and tetracycline (96%). The most prevalent antimicrobial resistance gene was tetM found in 93% of the isolates followed by ermTR, ermB, and tetK, found in 23%, 16%, and 16% of isolates, respectively. The genes, tetL, tetO, ermA, ermC and mefA were not detected in any of the S. agalactiae isolates. Of the 110 tetracycline resistant S. agalactiae, 89 isolates harbored the tetM gene alone and eighteen isolates carried the tetM gene with the tetK gene. All erythromycin-resistant isolates exhibited cMLSB resistance phenotype, 22 isolates harbored the ermTR gene alone and five isolates carried the ermTR gene with the ermB gene. The rate of coexistence of genes encoding the erythromycin and tetracycline resistance determinants was 34%. CONCLUSION: The present study demonstrated that S. agalactiae isolates obtained from urine samples showed a high rate of resistance to tetracycline, chloramphenicol and macrolide antibiotics and were commonly associated with the resistance genes temM, ermTR or ermB.

Detection of AmpC-ß-lactamases producing isolates among carbapenem resistant P. aeruginosa isolated from burn patient.

BACKGROUND AND OBJECTIVES: Pseudomonas aeruginosa is responsible for devastating nosocomial infections among severely burn patients. Class C of cephalosporinase (AmpC-ß-lactamases) is important cause of multiple ß-lactam resistance in P. aeruginosa. The aim of this study was to detect the AmpC-ß-lactamases producing isolates among carbapenem resistant P. aeruginosa isolated from burn patient. MATERIAL AND METHODS: a total of 100 isolates of carbapenem resistant P. aeruginosa isolates from different burn patients were investigated. Three phenotypic methods were selected for identification of the AmpC-ß-lactamases producing isolates. RESULTS: Fifty four isolates were AmpC producer as detected by AmpC disk test. Seventeen isolates were identified as AmpC producer using combined disk method. Fifty two isolates showed a twofold or threefold dilution difference between the minimum inhibitory concentration of imipenem or ceftazidime and the minimum inhibitory concentration of imipenem or ceftazidime plus cloxacillin. One isolate was identified as AmpC producer using three methods. Three isolates produced AmpC as detected by both AmpC disk test and combined disk methods and 19 isolates were found as AmpC producer using both AmpC disk test and minimum inhibitory concentration methods. Six isolates were AmpC producer as shown by the MICs of both imipenem and ceftazidime. CONCLUSION: According to the results of this study, AmpC- ß-lactamase looks to be the main mechanism of resistance of Pseudomonas aeruginosa to cephalosporins and carbapenems in the study hospital.

Genetic similarity between adenoid tissue and middle ear fluid isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis from Iranian children with otitis media with effusion.

BACKGROUND: Otitis media with effusion (OME) is a common disease among children, in the pathogenesis of which bacterial infections play a critical role. It was suggested that adenoid tissue could serve as a reservoir for bacterial infection, the eustachian tubes being the migration routes of bacteria into the middle ear cavity. The aim of this study was to investigate the genetic similarity between isolates of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, obtained from adenoid tissue and middle ear fluid. METHODS: A total of 60 specimens of middle ear fluids (MEFs) and 45 specimens of adenoid tissue were obtained from 45 children with OME. All the samples were inoculated on culture media for bacterial isolation and identification. The genetic similarity between bacterial isolates was determined by pulsed-field gel electrophoresis (PFGE). RESULTS: The same bacterial species were simultaneously isolated from adenoid tissue and MEFs of 14 patients, among which, 6 pairs of M. catarrhalis, 5 pairs of S. pneumoniae and 3 pairs of H. influenzae were identified. CONCLUSIONS: Based on the genetic similarities between isolate pairs, found by PFGE analysis, this study suggested that M. catarrhalis, S. pneumoniae and H. influenzae colonize the adenoid tissue, then migrate to the middle ear cavity and, hence, contribute to the total pathogenesis of OME.

Diagnosis of Helicobacter pylori infection by invasive and noninvasive tests

Although several invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection, all of the tests have their limitations. We conducted a study to investigate and compare the suitability of rapid urease test (RUT), serology, histopathology and stool antigen tests with polymerase chain reaction (PCR) for detection of H. pylori, and correlate the diagnostic methods with PCR. Eighty nine patients (61 adults, 28 children) referred to the Firoozgar Hospital and Children Medical Center Hospital for diagnostic upper gastrointestinal endoscopy entered to the study and noninvasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in feces were measured. The biopsies were utilized for histological examination, RUT and PCR. The H. pylori statuses were evaluated by the positivity of ureC PCR in biopsy specimens and 53 subjects had H. pylori positive result. Histopathology showed high overall performance in adults and children with sensitivity and specificity 100% and 90%, respectively. Sensitivity, specificity, and accuracy for stool antigen test were 87.8%, 75% and 82%, respectively. Correlation of RUT, serology (IgG), histopathology and stool antigen tests with PCR were 0.82, 0.32, 0.91 and 0.63, respectively. In conclusion, the RUT and histopathology are as accurate as the PCR of biopsy and stool antigen test can consider as appropriate noninvasive test for detection of H. pylori infection.

Normal and tumour cervical cells respond differently to vaginal lactobacilli, independent of pH and lactate.

Cervical cancer is a human papilloma virus (HPV)-related cancer, but most HPV infections are transient or intermittent and resolve spontaneously. Thus, other factors, such as cervical microflora, which are dominated by lactobacilli, must be involved in invasive cervical carcinoma development after HPV infection. Previous studies have demonstrated that lactobacilli have antitumour effects, and it is possible that vaginal lactobacilli prevent cervical cancer. Here we examined the proliferative and apoptotic responses of normal and tumour cervical cells to common vaginal lactobacilli components by investigating human normal fibroblast-like cervical (normal cervical) and HeLa (cervical tumour) cell responses to Lactobacillus gasseri and Lactobacillus crispatus. The effects of different lactobacilli components, such as culture supernatants, cytoplasmic extracts, cell-wall extracts and live cells, were determined by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, trypan blue staining, lactate dehydrogenase assay and colorimetric caspase-3 activity assay. Changes in caspase-3 and human chorionic gonadotropin ß (hCGß) expression were analysed by quantitative RT-PCR. Tumour cell growth inhibition by culture supernatants was higher than that by pH- and lactate-adjusted controls. However, the effects of the supernatants on normal cells were similar to those of lactate-adjusted controls. Apoptosis was inhibited by supernatants, which was consistent with higher hCGß expression since hCG inhibits apoptosis. Our study demonstrated that common vaginal lactobacilli exert cytotoxic effects on cervical tumour cells, but not on normal cells, and that this cytotoxicity is independent of pH and lactate. Our results encourage further studies on the interaction between lactobacilli and cervical cells, and administration of common vaginal lactobacilli as probiotics.

Molecular analysis of typical and atypical enteropathogenic Escherichia coli (EPEC) isolated from children with diarrhoea.

Diarrhoea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. To investigate the incidence, antimicrobial resistance and genetic relationships of enteropathogenic Escherichia coli (EPEC) in children with diarrhoea, a total of 612 stool specimens were collected in Tehran, Iran, and cultured to isolate strains of EPEC. The disc diffusion method was used to determine the susceptibility of the isolates according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The presence of eae, stx and bfp-A genes was determined by PCR. The genetic relationships between EPEC isolates were determined by pulsed-field gel electrophoresis (PFGE). Out of the 412 strains of E. coli obtained from 612 diarrhoeal stool specimens, 23 (5.6 %) were identified as EPEC, of which seven (30.4 %) were classified as typical strains of EPEC and 16 (69.6 %) were classified as atypical. Out of the 23 EPEC isolates, 69.5 % were resistant to ampicillin, 39.1 % were resistant to tetracycline and cotrimoxazole, 30.4 % were resistant to cefpodoxime, ceftazidime, ceftriaxone and aztreonam, and 26.1 % were resistant to imipenem. The isolates were classified into 21 pulsotypes by PFGE profiles. The present study shows that typical and atypical EPEC isolates displayed considerable heterogeneity in PFGE profiles and EPEC infections were only sporadic in Tehran. Overall 69 % of isolates were resistant to at least one of the antibiotics tested.

Diagnosis of Helicobacter pylori infection by invasive and noninvasive tests.

Although several invasive and noninvasive tests have been developed for the diagnosis of Helicobacter pylori infection, all of the tests have their limitations. We conducted a study to investigate and compare the suitability of rapid urease test (RUT), serology, histopathology and stool antigen tests with polymerase chain reaction (PCR) for detection of H. pylori, and correlate the diagnostic methods with PCR. Eighty nine patients (61 adults, 28 children) referred to the Firoozgar Hospital and Children Medical Center Hospital for diagnostic upper gastrointestinal endoscopy entered to the study and noninvasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in feces were measured. The biopsies were utilized for histological examination, RUT and PCR. The H. pylori statuses were evaluated by the positivity of ureC PCR in biopsy specimens and 53 subjects had H. pylori positive result. Histopathology showed high overall performance in adults and children with sensitivity and specificity 100% and 90%, respectively. Sensitivity, specificity, and accuracy for stool antigen test were 87.8%, 75% and 82%, respectively. Correlation of RUT, serology (IgG), histopathology and stool antigen tests with PCR were 0.82, 0.32, 0.91 and 0.63, respectively. In conclusion, the RUT and histopathology are as accurate as the PCR of biopsy and stool antigen test can consider as appropriate noninvasive test for detection of H. pylori infection.