Resistance pattern of Escherichia coli to levofloxacin in Iran: a narrative review.

Fluoroquinolones (FQs) are widely used in the treatment of infections caused by Escherichia coli. FQs are broad spectrum antibiotics with high tissue penetration, and ease of use. Therefore, given the concerns existing about drug resistance, we aim to review the latest findings about resistance patterns to levofloxacin (LVX) along with other FQs in E. coli infections in different parts of Iran. Evidence shows that quinolones have been used in Iran for nearly 50 years, and that 0-65% of E. coli isolates show resistance to FQs. In the western parts of Iran, the highest rate of resistance to LVX (66.7%) has been reported among patients having urinary tract infections with E. coli isolates. Few studies and information exist on the antimicrobial resistance of E. coli to LVX in different geographical locations of Iran. However, the findings of various studies on this subject show that E. coli resistance to LVX is more in the western part of Iran than in central and southern regions, but it is similar among inpatients and outpatients. Therefore, it is reasonable advisable to limit the overuse, inappropriate prescription, and self-medication of LVX to prevent the induction of FQ-resistant strains. Accordingly, in order to obtain a clearer image of resistance to FQs, especially LVX in E. coli in Iran, more extensive investigations in different geographical locations and periods of time are required. In addition, antimicrobial stewardship would be helpful in this regard.

Toxin A and B genes expression of Clostridium difficile in the sub-minimum inhibitory concentration of clindamycin, vancomycin and in combination with ceftazidime.

BACKGROUND AND OBJECTIVES: Antibiotics prescribed for infections have diverse effects on microbiota and the pathogen Clostridium difficile (C. difficile) as the most important antibiotic-associated diarrhea. This study aims to determine the gene expression of toxins A and B at the transcription level in the sub-MIC of vancomycin (VAN), clindamycin (CLI), and ceftazidime (CAZ) alone and in combination. MATERIALS AND METHODS: The MIC and fractional inhibitory concentration (FIC) of two C. difficile samples (a clinical isolate and ATCC 9689) were determined by microdilution and checkerboard microdilution methods, respectively. The total RNA was extracted from the medium inoculated with ∼106 CFU/mL of fresh bacteria in the pre-reduced medium containing ½ MIC of antibiotics alone and ½ FIC of antibiotics in combination. Real-time PCR was performed by sybrGreen methods in triplicate, and the data were analyzed by the comparative ΔΔCT method. RESULTS: All antibiotics except CAZ (alone and in combination) decreased the gene expression of toxins A and B within 24 hours. VAN and CLI reduced toxin gene expression within 24 and 48 hours. However, CAZ alone and in combination with VAN as well as CLI increased the gene expression of toxins A and B. CONCLUSION: The results confirmed toxin gene transcription and toxin production are associated with the type of isolates and antibiotics, as well as the combined form of antibiotics. This could be the reason which can explain the occurrence of C. difficile infection among patients who were treated with the third generation of cephalosporins alone and in combination with another antibiotic in the form of combinational therapy.

Effect of sub-MIC of vancomycin and clindamycin alone and in combination with ceftazidime on Clostridium difficile surface layer protein A (slpA) gene expression.

Clostridium difficile (C.difficile) infection is often established in the presence of antibiotics and probably antibiotics can influence surface layer protein A (slpA) expression as a colonization factor. The aim of this study is to evaluate the effect of vancomycin (VAN), clindamycin (CLI) alone and in combination with ceftazidime (CAZ) on slpA gene expression to determine whether such antibiotics can have any effect on slpA expression. About ∼106 CFU/mL was inoculated to medium containing an appropriate concentration of antibiotics alone and in combination. After 24 and 48 h incubation under anaerobic condition, 3 mL of culture was excluded and centrifuged in 8000 × g per 3 min. The pellet was washed and used for RNA extraction. The RNA extraction, Dnase I treatment and cDNA synthesis was performed by RNA extraction, Dnase I, and cDNA synthesis kits, respectively. The real-time PCR were carried out by sybrGreen methods and data were analyzed based on comparative ΔΔCT. All antibiotics alone and in combination, except VAN/CAZ in clinical isolate, decreased the level of slpA gene expression in the 24-h incubation. While the expression profile of slpA was different in the 48-h incubation period. The VAN and CLI decreased the slpA expression, although the template of expression is closed to control medium. CAZ alone and in combination increased slpA expression. C. difficile may down-regulate slpA expression in the early stages of growth in sub-inhibitory concentration of antibiotics. But, over time C. difficile increases or over expresses the slpA expression level. Consequently C. difficile binds strongly to epithelial cells and continues to survive in the presence of sub-MIC concentration of antibiotics. This effect is observed especially with regard to CAZ and probably other third generation cephalosporins or in combination therapy with VAN or CLI, which are prescribed in the clinic. CAZ can interfere with the anti-down regulatory feature of VAN, CLI, and maybe other antibiotics.

Toxin production of Clostridium difficile in sub-MIC of vancomycin and clindamycin alone and in combination with ceftazidime.

Toxin production in Clostridium difficile (C. difficile) is a key process for induction of diarrhea. Several factors such as sub-MIC of antibiotics impact on toxin production. The aim of this research is investigation of sub-minimum inhibitory concentration (sub-MIC) of vancomycin (VAN), clindamycin (CLI) separately and in combination with ceftazidime (CAZ) on toxin production in C. difficile. About ∼106 colony forming units (CFU) from 18-h culture of C. difficile ATCC 9689 and clinical isolates A+/B+/CTD-, were cultured anaerobically in the pre-reduced medium with appropriate concentration of separated and in combination antibiotics. After 24 and 48 h, 1 mL of culture was removed, centrifuged and the supernatant stored at-70 °C for later use. The evaluation of toxin production was carried out by the ELISA technique. All antibiotics alone and in combination formats inhibited toxin production over a period of 24 h. This effect is also observed in presence of VAN and CLI during a period of 48 h. Over a 4 h period, CAZ increased toxin production alone and in combination, especially with CLI. The data showed VAN and CLI decrease the level of toxins. In contrast, the CAZ not only increases the level of produced toxin, but also can interfere with VAN and CLI. Based on the results, combination therapy which is performed for treatment or prevention of other infections may cause toxin production and probably the severity of C. difficile AAD to increase.

The SDF-1 3'a genetic variation of the chemokine SDF-1α (CXCL12) in parallel with its increased circulating levels is associated with susceptibility to MS: a study on Iranian multiple sclerosis patients.

Immune system-related factors are important in pathogenesis of multiple sclerosis. The CXC chemokine SDF-1α (CXCL12) is involved in the immune responses. Hence, the aim of this study was to investigate the association between serum levels of SDF-1α (CXCL12) and its gene polymorphisms at position +801 with multiple sclerosis. In this experimental study, blood samples were collected from 100 multiple sclerosis patients and 100 healthy controls on EDTA pre-coated tubes. DNA was extracted and DNA samples were analyzed for SDF-1α (CXCL12) polymorphisms using PCR-RLFP in patients and controls. The serum levels of SDF-1α (CXCL12) were measured by ELISA. Demographic data were also collected by a questionnaire which was designed specifically for this study. Our results showed a significant difference between the A/A, A/G, and G/G genotype and A and G alleles of polymorphisms at position +801 of SDF-1α (CXCL12). Our results also showed that serum levels of SDF-1α (CXCL12) were markedly higher in patients than healthy controls, but no association was observed between SDF-1α (CXCL12) polymorphism and its serum levels. The results of this study might suggest the serum levels of SDF-1α (CXCL12) and its polymorphism play an important role in pathogenesis of multiple sclerosis. It is also worth noting that these factors could probably use as pivotal biological markers in the diagnosis of MS.

Post-transfusion occult hepatitis B (OBI): a global challenge for blood recipients and health authorities.

Hepatitis B is one of the most frequent post-transfusion infections. Occult hepatitis B infection (OBI) is a form of hepatitis B infection in which, despite the presence of HBV-DNA in the serum and hepatocytes of the carrier, HBsAg is absent. In addition to the risk of transmission through the transfusion of infected blood, reactivation of hepatitis B in OBI patients and recipients of their blood can lead to cirrhosis, hepatic cancer, and reactivation of viral replication in the carrier. Therefore, effective assays to assess and screen for OBI in blood donors are of paramount importance and require urgent attention. Recently, several investigations in various regions of Iran have reported OBI in blood donors. In response, there has been a drive to apply more specific, sensitive, and accurate methods for the detection of HBV, which should become an obligatory screening process for all blood transfusion services. In this review, we address the progression of occult hepatitis B and the common problems associated with occult hepatitis B worldwide. Finally, we reflect on the research and screening that is being performed in Iran to deal with this problem.

Cytokine patterns after therapy with Avonex®, Rebif®, Betaferon® and CinnoVex™ in relapsing-remitting multiple sclerosis in Iranian patients.

AIM: Several lines of evidence exist which suggest that changes in the expression of circulating cytokines are linked to the development or reoccurrence of multiple sclerosis (MS). This study aimed to evaluate the serum levels of relevant cytokines after therapy with IFN-ß formulations in MS patients. MATERIALS & METHODS: In this study, blood samples were collected from 70 MS patients undergoing four different types of IFN-ß formulation treatment and 100 healthy controls. After 24 months of treatment, the serum levels of IL-17A, IL-12, IFN-γ and IL-10 in patients and healthy controls were analyzed by ELISA. RESULTS: Our results demonstrated that serum levels of IL-17A were significantly higher in patients treated with CinnoVex™ and Avonex® when compared with healthy controls. Serum levels of IL-10 were significantly decreased after therapy with CinnoVex, whereas serum levels of IFN-ß were elevated. No difference in serum levels of IL-12 were detected between patients and controls. CONCLUSION: Results of our study suggest that CinnoVex and Avonex modulate the immune system less than Rebif® and Betaferon® in MS patients, and an elevated dose of CinnoVex and Avonex may be required for better regulation of the immune system in MS patients.

Assessment of CXCL12 (SDF-1α) polymorphisms and its serum level in posttransfusion occult HBV-infected patients in Southeastern Iran.

BACKGROUND: Occult hepatitis B infection (OBI) is defined as a form of hepatitis in which, despite absence of detectable HBsAg, HBV-DNA is present in peripheral blood of patients. The main aim of this study was to determine an association between polymorphisms in +801 of CXCL12 (SDF-1α) and its serum level in OBI patients. METHODS: In this experimental study, plasma samples of 3700 blood donors were tested for HBsAg and anti-HBc by ELISA. The HBsAg(-)/anti-HBc(+) samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples assigned as OBI cases and PCR-RFLP techniques were performed to examine the CXCL12 (SDF-1α) polymorphisms. The serum level of CXCL12 (SDF-1α) was also analyzed by ELISA. RESULTS: Of 3700 blood samples, 352 (9.5%) were HBsAg/anti-HBc(+) and HBV-DNA was detected in 57/352 (16.1%) of HBsAg(-)/anti-HBc(+) samples. Our results showed a significant difference in genotypes and alleles of +801 region of CXCL12 (SDF-1α). However, the serum level of CXCL12 (SDF-1α) was decreased in OBI patients but was not significant. Our results also showed that the alleles of +801 region of CXCL12 (SDF-1α) were also not associated with serum level of the chemokine. CONCLUSIONS: The polymorphisms in +801 region of CXCL12 (SDF-1α) are possibly related to OBI.

No detected hepatitis B virus-DNA in thalassemic patients infected by hepatitis C virus in Kerman province of Iran.

This research was aimed to investigate the prevalence and clinical impact of occult HBV infection in thalassemic patients with chronic HCV infection. In this cross-sectional study we have totally examined 60 patients suffering HBV and HCV infections by PCR and RT-PCR methods, respectively, in Kerman province of Iran. ELISA technique (RADIM, Italy) was used to detect anti-HBc, anti-HBs and HBsAg. The serum level of liver enzymes (SGOT, SGPT, DB, TB and ALK) were analyzed in the HCV infected patients (MAN, IRAN). Statistical analyses performed using t-test and Chi-square. We found that 27 cases (out of 60) were infected by HCV but HBV-DNA was not seen in HCV infected patients. Present findings also showed that none of samples were HBsAg positive but 9 (33%) (out of 27) HCV-RNA positive patients were anti-HBc positive and 11 (40.7%) were positive for anti-HBs. We found that SGOT, SGPT, DB, TB and ALK are above normal in 27 (100%), 19(70.3%), 12(44.5%), 15 (55.5%) and 15 (55.5%) RNA-HCV positive patients, respectively. The prevalence of hepatitis C infection is very high in thalassemic patients and based on other studies our results showed that the prevalence of HCV infection in Kerman is more than other provinces of Iran. In contrast with other studies HBV-DNA in these patients could not be detected, hence, it seems that occult HBV infection isn't frequent in Iranian thalassemic patients who suffering from chronic HCV infection.