Erythromycin was the first macolide discovered in 1952. In 1990s new macrolides including clarithromycin, azithromycin, and dirithromycin were introduced to the market. We provide a review of their structure, pharmacokinetics. mechanisms of action, and indications in dermatology.

Background: Antimicrobial resistance of Streptococcus pneumoniae (S. pneumoniae) has shown major changes in recent years. On the other hand, macrolide antibiotics are being increasingly used in clinical practice. Several studies have reported increased resistance to this group of antibiotics, while there is no comprehensive information in this area. Accordingly, the present study was designed to estimate the resistance of S. pneumoniae to macrolides in Iran. Materials and Methods: In this review, articles (2000-2017), evaluating the level and type of S. pneumoniae resistance to macrolides in Iran, were extracted by searching different databases, and the results were analyzed. Results: A total of 25 relevant articles were retrieved and analyzed. Overall, 2723 cases had been recruited in these studies. The mean percentage of resistance to macrolides was estimated at 48. 43% (CI, 38. 8-57. 9%). In the majority of reported cases, the resistance mechanisms included ribosomal methylation (i. e., ermB mutation), dual resistance, and efflux-mediated resistance. Conclusion: Based on the findings, the resistance rates are considerable in different cities of Iran. Therefore, without determining the type of drug resistance in clinical samples, use of macrolides is not recommended for treatment purposes. In addition, considering the type of resistance mechanisms in Iran, use of higher drug doses is probably ineffective.

Introduction: macrolides are a group of antibacterial agents. Given their clinical importance, and the consistent rise in resistance among pathogenic bacteria, macrolides have been the targets of extensive research. Materials and Methods: This review considered the number of macrolides in different wastewater and the removal of these drugs. The antibiotics were frequently detected in influents and effluents, ranged from ng/L up to lower μ, g/L. In influent, the highest concentrations of clarithromycin (6080 ng/L), roxithromycin (>103 ng/L), erythromycin (3900 ng/L), and azithromycin (1949 ng/L) were detected in Croatia, Chinese, USA, and Singapore municipal wastewater treatment plants, respectively. Results: The removal efficiency of macrolides during wastewater treatment processes varies and is essentially dependent on a combination of macrolides physicochemical properties, location of municipal wastewater, and the operating conditions of the treatment systems. The application of alternative techniques, including membrane separation, activated carbon adsorption, advanced oxidation processes, biodegradation, and disinfection were the dominant removal routes for macrolides in different wastewater treatment processes. A combination of these techniques can also be used, leading to higher removals, which may be necessary before the final disposal of the effluents or their reuse for irrigation or groundwater recharge. Conclusion: Many antibiotics cannot be removed completely in wastewater treatment processes and would enter into the environment via effluent and sludge. The molecular structure of macrolides and their load-bearing capacity has led to the advantage of biological treatment over other treatments. However, the main part of the treatment has been done using biological treatment.

Polychlorinated biphenyls (PCBs) cause many significant ecological problems because of their low degradability, high harmfulness, and solid bioaccumulation. Two bacterial strains were isolated from soil that had been polluted with electrical transformer liquid for more than 40 years. The isolates were distinguished as Lysinibacillus macrolides DSM54Tand Bacillus firmus NBRC15306Tthrough 16S rRNA sequencing analysis. This is the primary report of an agent of the genus Bacillus firmus equipped for the removal of PCBs. The strains could develop broadly on 2-Chlorobiphenyl and 2, 4-dichlorobiphenyl. GC/MS analysis of individual congeners revealed up to 80% degradation of the xenobiotics in 96h, attendant with cell proliferation of up to two orders of extent. More extensive investigation of the isolates may be helpful in surveying detoxification forms and in planning bioremediation and bioaugmentation strategies.

Background: macrolides have shown beneficial effects in the treatment of chronic rhinosinusitis (CRS). This study aimed to compare the effect of azithromycin and clarithromycin in combination with conventional therapies for the treatment of CRS. Methods: This single-blind randomized controlled trial was conducted during 2018-2019 at the Otorhinolaryngology Clinic of Shahid Mohammadi Hospital, Bandar Abbas, Iran. Out of 102 selected patients, 90 were included in the analysis. Patients were selected through convenience sampling and randomly assigned to two equal groups. In addition to conventional therapies (nasal irrigation, betamethasone injection, oxymetazoline and fluticasone spray, guaifenesin syrup, and steam inhalation), the patients in the clarithromycin group received clarithromycin 500 mg tablets twice daily for four weeks. The other group received azithromycin 500 mg tablets daily for four weeks. Patients’,symptoms were evaluated pre-and post-intervention, and the Lund-Mackay (LM) scoring system was used for the staging of CRS based on computed tomography scan findings. Data were analyzed using SPSS software, and P<0. 05 was considered statistically significant. Results: Patients in both groups were comparable in terms of age and sex. Complete resolution of symptoms was significantly higher in the azithromycin group than the clarithromycin group (71. 1% vs. 24. 4%, P<0. 001). Baseline LM scores did not differ significantly between the groups (P=0. 120). However, postintervention, LM scores reduced considerably in both groups, but the change was significantly higher in the azithromycin group (P<0. 001). Conclusion: In combination with conventional therapies for CRS in adults, a four-week course of treatment with azithromycin is more effective than clarithromycin.

Background: Epidemiological data on antibiotic susceptibility of Staphylococcus strains isolated from nasal carriers in each region can be helpful to select appropriate drugs to eradicate carriage states, control nosocomial infections and also treat patients. Objectives: The current study aimed to investigate the antibiotic resistance profile and the molecular prevalence of the ermA, ermB, ermC and msrA genes among Staphylococcus strains isolated from the anterior nares of hospital employees. Patients and Methods: In this cross-sectional study, a total of 100 Staphylococcus isolates, 51 Staphylococcus aureus, 49 coagulasenegative staphylococci (CoNS) were isolated from the anterior nares of hospital employees in Khorramabad, Iran. Susceptibility pattern to macrolide antibiotics were determined using the disk diffusion method. The polymerase chain reaction (PCR) assay was applied to determine the major erythromycin-resistant genes (ermA, ermB, ermC and msrA). Results: Fifty-three (53%) isolates were simultaneously resistant to erythromycin, azithromycin and clarithromycin (crossresistance); while 8 (8%) isolates had variable macrolide susceptibility pattern. Among the S. aureus isolates, the difference in prevalence of resistance to erythromycin between males and females was significant (P = 0. 011). The frequency of ermA, ermB, ermC, and msrA genes were 3%, 5%, 33% and 20%, respectively. It was also found that out of 53 isolates resistant to erythromycin, 44 (83%) isolates (eight S. aureus and thirty-six CoNS strains) carried at least one of the four tested genes. Eight (8%) isolates had intermediate phenotype to erythromycin, in which 4 (50%) isolates carried ermB or ermC genes. In addition, out of 39 erythromycin-susceptible isolates, 3 (7. 7%) isolates were positive for ermB or ermC genes. Conclusions: No entire association was found between genotype and phenotype methods to detect macrolides-resistant isolates. In addition, distribution of genetically erythromycin-resistant isolates is geographically different among staphylococci. It is recommend removing S. aureus from nasal carriers by proved approaches such as local or systemic administration of effective antibiotics or bacterial interference.

Background: Group A streptococci (GAS) are notorious bacteria causing a wide variety of clinical manifestations ranging from mild, acute streptococcal pharyngitis to chronic non-suppurative diseases and immunological sequelae. They are further complicated by the global rise on the emergence of macrolide resistance amongthese bacteria in which severalMprotein gene (emm) and sequence types are associated with invasive diseases. Objectives: The current study aimed at determining the erythromycin resistance patterns and molecular characteristics of GAS clinical strains by emm and multilocus sequence typing (MLST) methods. Methods: Thirty-five GAS clinical isolates were subjected to antibiotic susceptibility testing by disk diffusion method. Theminimum inhibitory concentration (MIC) of erythromycin against GAS by E-test was determined. Clinical and laboratory standards institute (CLSI) guideline was used for the interpretation of results. Detection of ermA, ermB, and mefA genes by polymerase chain reaction (PCR) was performed and emm typing was done by amplification and sequencing of emm genes per standard protocol. Allele and sequence type (ST) of GAS were obtained using the S. pyogenes MLST database. Results: All the isolates were sensitive to erythromycin, penicillin, clindamycin, chloramphenicol, and vancomycin (100%). Resistance to tetracycline was 54. 3%. The mefA gene was found in one erythromycin susceptible isolate. No other erythromycin resistance genes were detected in the isolates. Twenty different emm types were found and the most frequent emm types/subtypes detected were emm1, emm18. 21, emm28. 5, emm97. 4, and emm102. 2 (each 8. 6%). However, no new emm type was detected. A total of 15 sequence types (STs), eight clonal clusters (CCs), and eight singletons were identifiedamong21 representative isolates. Three isolates exhibited CC1 (ST28/emm1). Conclusions: High susceptibility of GASisolates against erythromycin could be due to low antibiotic selective pressure in Malaysian clinical settings. High diversity of emmandST types revealed the heterogenic nature of the strains circulating in Malaysian hospitals. Continuous epidemiological monitoring by molecular typing methods is warranted to improve the management strategies of GAS infections in future.

Antibiotic resistance in Streptococcus pneumoniae infection is responsible for 1.6 million deaths per year. The discovery of antimicrobials has reduced the morbidity and mortality of pneumococcal disease, but the use of inappropriate dosages has contributed to the emergence of resistant microbes. Increasing microbial resistance means there are fewer treatment alternatives worldwide. Antibiotics can safely be used to develop antibiograms that monitor resistance trends and guide infection treatment guidelines. This study aims to determine the effectiveness of penicillin and macrolide as broad-spectrum antibiotics for therapy and serotypes that cause resistance to Streptococcus pneumoniae. The systematic review method database of the scientific research platform was systematically searched. This systematic review is registered with PROSPERO ID CRD42023400159. This work showed that penicillin resistance was between 61.7% and 98%; the highest was 100%, and the lowest resistance was 10.5%. The resistant serotypes that appear are 6A, 6B, and 19A. While macrolide resistance is between 21% and 69.4%, the highest resistance is 100%, and the lowest resistance is 2%, with resistance-causing genes that often appear as ermB and mefA. Conclusion Data shows high penicillin resistance against Streptococcus pneumoniae with frequently occurring serotypes 6A, 6B, and 19A, and the trend of resistance to macrolides is increasing with the causative genes ermB and mefA. These antibiotic usage recommendations are regulated by clear regulations