Background: Antimicrobial resistance is a major problem in treatment and public health, and it has been increasing over the last few decades. Hence, serious measurements are needed to overcome this challenge. In this study, we evaluated antibacterial and antifungal activity of some nanocomposites including titanium dioxide (5a), polyimide nanocomposites containing cerium oxide (5b), silver-titanium dioxide nanoparticles prepared under desired conditions (5c), polyaniline/wheat husk ash PANI /WHA (5d), Ag-TiO2 prepared by sol–gel route (5e), and cellulose-graphene (5f) against some bacterial and fungal strains, which are the most common agents in many infectious diseases. Methods: The nanoparticles were prepared in desired condition. The agar dilution and well agar diffusion methods were used for determination of inhibition zoon and minimum inhibitory concentration (MIC) during preliminary evaluation of antimicrobial activity against Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Results: The results showed that the nanocomposites had good activity against gram-negative bacteria. Conclusions: Our results showed that the inhibitory activity of these nanocomposites on gram-negative bacteria was better than gram-positive bacteria.
{"title":"Antibacterial Activity of New Compounds Based on Nanocomposites","authors":"Maryam Kouhkan, F. Ghanbary, F. Karimi","doi":"10.34172/ajcmi.2021.17","DOIUrl":"https://doi.org/10.34172/ajcmi.2021.17","url":null,"abstract":"Background: Antimicrobial resistance is a major problem in treatment and public health, and it has been increasing over the last few decades. Hence, serious measurements are needed to overcome this challenge. In this study, we evaluated antibacterial and antifungal activity of some nanocomposites including titanium dioxide (5a), polyimide nanocomposites containing cerium oxide (5b), silver-titanium dioxide nanoparticles prepared under desired conditions (5c), polyaniline/wheat husk ash PANI /WHA (5d), Ag-TiO2 prepared by sol–gel route (5e), and cellulose-graphene (5f) against some bacterial and fungal strains, which are the most common agents in many infectious diseases. Methods: The nanoparticles were prepared in desired condition. The agar dilution and well agar diffusion methods were used for determination of inhibition zoon and minimum inhibitory concentration (MIC) during preliminary evaluation of antimicrobial activity against Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Results: The results showed that the nanocomposites had good activity against gram-negative bacteria. Conclusions: Our results showed that the inhibitory activity of these nanocomposites on gram-negative bacteria was better than gram-positive bacteria.","PeriodicalId":8689,"journal":{"name":"Avicenna Journal of Clinical Microbiology and Infection","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73606115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anahita Farajzadeh, M. Mirzaee, S. Nanekarani, R. Yari
Background: Acinetobacter baumannii is a common cause of nosocomial infections. A prominent feature of these bacteria is resistance to carbapenems. This study aimed to identify OXA genes encoding oxacillinase in Acinetobacter baumannii isolates. Methods: This cross-sectional descriptive study was performed on 25 environmental A. baumannii isolates collected from ICU over 8 months. Definitive identification of isolates was performed by biochemical tests and polymerase chain reaction (PCR) of 16s rRNA gene. Antibiotic susceptibility testing was performed on Müller-Hinton agar medium by disk diffusion and E-test. Antibiogram and multiplex PCR data of beta-lactamase genes were collected and analyzed at a significance level of P<0.05 using SPSS 22.0. Results: Except for one isolate, all isolates (96%) were sensitive to polymyxin B and 80% of isolates were sensitive to oxacillin. All isolates were sensitive to meropenem, ampicillin/sulbactam, gentamicin, amikacin, piperacillin, and carbenicillin. The results showed that 25 isolates (100%) had OXA-51 gene, 21 isolates (84%) had OXA-58 gene, one isolate (4%) had OXA-24 gene, and none of the isolates contained OXA-23 gene. Only isolate No.10 had three oxacillinase genes simultaneously and it was resistant to oxacillin, polymyxin B, and cephalothin. Conclusions: The study showed that environmental isolates of ICU do not have pathogenic genes present in the clinical isolates, and how these genes are transferred to the peripheral isolates is an important point that should be studied. Identification of genes encoding carbapenem resistance may help to understand the mechanisms of resistance transfer in A. baumannii. The lack of the OXA-23 gene plays an important role in the susceptibility of isolates to antibiotics and non-emergence of resistant strains.
{"title":"Application of Multiplex PCR for the Identification of Oxacillinase Genes and Determination of Antibiotic Resistance Pattern in Environmental Isolates of Acinetobacter baumannii in ICU","authors":"Anahita Farajzadeh, M. Mirzaee, S. Nanekarani, R. Yari","doi":"10.34172/ajcmi.2021.16","DOIUrl":"https://doi.org/10.34172/ajcmi.2021.16","url":null,"abstract":"Background: Acinetobacter baumannii is a common cause of nosocomial infections. A prominent feature of these bacteria is resistance to carbapenems. This study aimed to identify OXA genes encoding oxacillinase in Acinetobacter baumannii isolates. Methods: This cross-sectional descriptive study was performed on 25 environmental A. baumannii isolates collected from ICU over 8 months. Definitive identification of isolates was performed by biochemical tests and polymerase chain reaction (PCR) of 16s rRNA gene. Antibiotic susceptibility testing was performed on Müller-Hinton agar medium by disk diffusion and E-test. Antibiogram and multiplex PCR data of beta-lactamase genes were collected and analyzed at a significance level of P<0.05 using SPSS 22.0. Results: Except for one isolate, all isolates (96%) were sensitive to polymyxin B and 80% of isolates were sensitive to oxacillin. All isolates were sensitive to meropenem, ampicillin/sulbactam, gentamicin, amikacin, piperacillin, and carbenicillin. The results showed that 25 isolates (100%) had OXA-51 gene, 21 isolates (84%) had OXA-58 gene, one isolate (4%) had OXA-24 gene, and none of the isolates contained OXA-23 gene. Only isolate No.10 had three oxacillinase genes simultaneously and it was resistant to oxacillin, polymyxin B, and cephalothin. Conclusions: The study showed that environmental isolates of ICU do not have pathogenic genes present in the clinical isolates, and how these genes are transferred to the peripheral isolates is an important point that should be studied. Identification of genes encoding carbapenem resistance may help to understand the mechanisms of resistance transfer in A. baumannii. The lack of the OXA-23 gene plays an important role in the susceptibility of isolates to antibiotics and non-emergence of resistant strains.","PeriodicalId":8689,"journal":{"name":"Avicenna Journal of Clinical Microbiology and Infection","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75790919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. K. Marak, Sudipta Roy, Tanusree Mondal, M. Sarkar, T. Ghosh, J. Dey
Background: Leprosy is an infectious disease which faces diagnostic challenges. Slit-skin smear (SSS) is an age simple diagnostic technique, yet not commonly applied by health care providers. The study aimed to determine the effectiveness of SSS in terms of validity, diagnostic accuracy, and percentage agreement against punch biopsy in diagnosing leprosy among leprosy patients who were diagnosed with leprosy on clinical grounds only (i.e., number of skin lesions and/or peripheral nerve thickening). Methods: An evaluation study of diagnostic tests with a cross-sectional design was conducted at a tertiary care center of Bankura. In general, 70 new untreated leprosy patients, diagnosed solely by clinical grounds (i.e., count of skin lesions and/or thickening of the nerve) and attending the dermatology outpatient department (From February 2019 to January 2020) were enrolled in this study. After excluding pure neuritic, relapse, and seriously ill patients by consecutive sampling, they were subjected to both SSS and punch biopsy using a standard process. SPSS for Windows (Version 16.0., Chicago, SPSS Inc.) was used to analyze data. Z test, chi-square test, and kappa test were conducted to test the statistical significance between the effectiveness of SSS and punch biopsy. Results: The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and diagnostic accuracy of SSS were 81.81%, 95.83%, 90%, 92%, 20%, 0.19%, 102.87%, and 91.42%, respectively. Based on the results, SSS could detect acid-fast bacilli (AFB) in clinically diagnosed leprosy cases slightly less than punch biopsy, but it was statistically insignificant (Z=0.3689, P=0.71138, df=1). Finally, Cohen’s Kappa coefficient was 0.796, representing substantial agreement between SSS and punch biopsy (95% CI: 0.641-0.951). Conclusions: Overall, SSS is more or less equally effective as compared to punch biopsy in confirming leprosy cases. Interest and training on SSS among resident doctors should be emphasized accordingly.
背景:麻风病是一种面临诊断挑战的传染病。裂隙皮肤涂片(SSS)是一种年龄简单的诊断技术,但不常用的卫生保健提供者。该研究旨在确定SSS在诊断麻风方面的有效性,诊断准确性,以及在仅根据临床诊断为麻风的麻风患者(即皮肤病变数量和/或周围神经增厚)中与穿孔活检诊断麻风的百分比一致性。方法:在班库拉一家三级保健中心进行了一项横断面设计的诊断试验评价研究。总体而言,本研究纳入了70例新的未经治疗的麻风患者,这些患者仅通过临床依据(即皮肤病变计数和/或神经增厚)进行诊断,并在皮肤科门诊就诊(2019年2月至2020年1月)。在通过连续取样排除纯神经性炎、复发和重症患者后,他们使用标准流程进行SSS和穿孔活检。SPSS for Windows (Version 16.0)使用SPSS Inc.)对数据进行分析。采用Z检验、卡方检验、kappa检验检验SSS与穿孔活检的疗效是否有统计学意义。结果:SSS的敏感性、特异性、阳性预测值、阴性预测值、阳性似然比、阴性似然比、诊断优势比(DOR)、诊断准确率分别为81.81%、95.83%、90%、92%、20%、0.19%、102.87%、91.42%。结果显示,SSS对麻风临床诊断病例抗酸杆菌(AFB)的检出率略低于针刺活检,但差异无统计学意义(Z=0.3689, P=0.71138, df=1)。最后,Cohen’s Kappa系数为0.796,表明SSS和穿孔活检之间基本一致(95% CI: 0.641-0.951)。结论:总的来说,在麻风病的诊断中,SSS与穿刺活检或多或少是一样有效的。应重视住院医师对SSS的兴趣和培训。
{"title":"Evaluation of Slit-Skin Smear Against Punch Biopsy in Diagnosing Leprosy: A Cross-sectional Study in a Tertiary Care Centre of West Bengal","authors":"L. K. Marak, Sudipta Roy, Tanusree Mondal, M. Sarkar, T. Ghosh, J. Dey","doi":"10.34172/ajcmi.2021.15","DOIUrl":"https://doi.org/10.34172/ajcmi.2021.15","url":null,"abstract":"Background: Leprosy is an infectious disease which faces diagnostic challenges. Slit-skin smear (SSS) is an age simple diagnostic technique, yet not commonly applied by health care providers. The study aimed to determine the effectiveness of SSS in terms of validity, diagnostic accuracy, and percentage agreement against punch biopsy in diagnosing leprosy among leprosy patients who were diagnosed with leprosy on clinical grounds only (i.e., number of skin lesions and/or peripheral nerve thickening). Methods: An evaluation study of diagnostic tests with a cross-sectional design was conducted at a tertiary care center of Bankura. In general, 70 new untreated leprosy patients, diagnosed solely by clinical grounds (i.e., count of skin lesions and/or thickening of the nerve) and attending the dermatology outpatient department (From February 2019 to January 2020) were enrolled in this study. After excluding pure neuritic, relapse, and seriously ill patients by consecutive sampling, they were subjected to both SSS and punch biopsy using a standard process. SPSS for Windows (Version 16.0., Chicago, SPSS Inc.) was used to analyze data. Z test, chi-square test, and kappa test were conducted to test the statistical significance between the effectiveness of SSS and punch biopsy. Results: The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and diagnostic accuracy of SSS were 81.81%, 95.83%, 90%, 92%, 20%, 0.19%, 102.87%, and 91.42%, respectively. Based on the results, SSS could detect acid-fast bacilli (AFB) in clinically diagnosed leprosy cases slightly less than punch biopsy, but it was statistically insignificant (Z=0.3689, P=0.71138, df=1). Finally, Cohen’s Kappa coefficient was 0.796, representing substantial agreement between SSS and punch biopsy (95% CI: 0.641-0.951). Conclusions: Overall, SSS is more or less equally effective as compared to punch biopsy in confirming leprosy cases. Interest and training on SSS among resident doctors should be emphasized accordingly.","PeriodicalId":8689,"journal":{"name":"Avicenna Journal of Clinical Microbiology and Infection","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83499760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Bacteriocins are heterogeneous inhibitory substances that could affect the bacteria belonging to the same genus. Both gram-positive and gram-negative bacteria produce bacteriocins. One of the best sources of producing bacteriocins is Lactobacillus. The aim of this study was to isolate and purify bacteriocin from Lactobacillus rhamnosus and assess its effects on Pseudomonas aeruginosa and synthesis of its lipopolysaccharide. Methods: L. rhamnosus was prepared and cultured at MRS broth and incubated at 37ºC for 24 hours. Then, the medium was centrifuged for the isolation of bacteriocin and the supernatant was considered as bacteriocin. Antibacterial properties of different concentrations of bacteriocin (50, 100, 200, and 400 μg/mL) against P. aeruginosa were assayed by using agar diffusion and broth micro dilution methods. Also, the effect of bacteriocin against lipopolysaccharide synthesis in P. aeruginosa was analyzed by using one unit of minimum inhibitory concentration (MIC) for bacteriocin. Results: The results showed that all bacteriocin concentrations had antibacterial activity against P. aeruginosa. The MIC value was 31.25 μg/mL and minimal bactericidal concentration (MBC) was 62.5 μg/mL. Also, the synthesis of lipopolysaccharide decreased during P. aeruginosa growth period, and it reached zero after 5 hours. Conclusions: The results of this study showed the antibacterial effect of bacteriocin isolated from L. rhamnosus against P. aeruginosa. In addition, this bacteriocin prevented the lipopolysaccharide synthesis in P. aeruginosa.
{"title":"The Effect of Bacteriocin Isolated From Lactobacillus rhamnosus on Pseudomonas aeruginosa Lipopolysaccharides","authors":"Hafizeh Haghighatafshar, R. Talebi, A. Tukmechi","doi":"10.34172/ajcmi.2021.09","DOIUrl":"https://doi.org/10.34172/ajcmi.2021.09","url":null,"abstract":"Background: Bacteriocins are heterogeneous inhibitory substances that could affect the bacteria belonging to the same genus. Both gram-positive and gram-negative bacteria produce bacteriocins. One of the best sources of producing bacteriocins is Lactobacillus. The aim of this study was to isolate and purify bacteriocin from Lactobacillus rhamnosus and assess its effects on Pseudomonas aeruginosa and synthesis of its lipopolysaccharide. Methods: L. rhamnosus was prepared and cultured at MRS broth and incubated at 37ºC for 24 hours. Then, the medium was centrifuged for the isolation of bacteriocin and the supernatant was considered as bacteriocin. Antibacterial properties of different concentrations of bacteriocin (50, 100, 200, and 400 μg/mL) against P. aeruginosa were assayed by using agar diffusion and broth micro dilution methods. Also, the effect of bacteriocin against lipopolysaccharide synthesis in P. aeruginosa was analyzed by using one unit of minimum inhibitory concentration (MIC) for bacteriocin. Results: The results showed that all bacteriocin concentrations had antibacterial activity against P. aeruginosa. The MIC value was 31.25 μg/mL and minimal bactericidal concentration (MBC) was 62.5 μg/mL. Also, the synthesis of lipopolysaccharide decreased during P. aeruginosa growth period, and it reached zero after 5 hours. Conclusions: The results of this study showed the antibacterial effect of bacteriocin isolated from L. rhamnosus against P. aeruginosa. In addition, this bacteriocin prevented the lipopolysaccharide synthesis in P. aeruginosa.","PeriodicalId":8689,"journal":{"name":"Avicenna Journal of Clinical Microbiology and Infection","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89266841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Hudu, Saadatu Haruna Shinkafi, Shuaibu Umar, B. Makun
Background: Rhinoviruses (RVs) represent the most important aetiological agents of the common cold and are responsible for about two-thirds of acute exacerbations of chronic bronchitis, asthma, and chronic obstructive pulmonary disease (COPD) in both children and adults. This study aimed to design a pan-serotypic vaccine capable of inducing cross-reactive antibodies against most of the RV by using a reverse Vaccinology approach. Methods: Bioinformatics analysis was carried out to characterise the capsid proteins (VP1, VP2, VP3, and VP4) of all known RV serotypes and to predict potential immune motifs. Conserved motifs consisting at least nine-mers common across all RV-A or B serotypes were selected and synthesized chemically. Four tagged full-length genes coding the capsid proteins of an ideal strain (HRV-74), VP1, VP2, VP3, and VP4 were constructed and cloned in vitro. Upon expression , the purified recombinant proteins were also administered subcutaneously to other groups of rabbits. The responses and cross-reactivity of the specific immunoglobulin M (IgM) and G (IgG) to the peptides, proteins, and whole viruses were measured. Results: The obtained anti-peptide antibodies exhibited a cross-neutralizing activity for different RV strains in vitro. Antibodies raised to the synthetic peptides exhibited cross-reactivity against the corresponding recombinant proteins and antigenically distinct RV strains coated on plates via ELISA assay. Conclusions: The study findings indicated that the peptides corresponding to the conserved region of the RV capsid proteins were potent immunogenic; moreover, the findings showed that their combination was crucial for extending the cross-protection against variant RVs.
{"title":"Reverse Vaccinology Approach for a Potential Rhinovirus Vaccine","authors":"S. Hudu, Saadatu Haruna Shinkafi, Shuaibu Umar, B. Makun","doi":"10.34172/ajcmi.2021.12","DOIUrl":"https://doi.org/10.34172/ajcmi.2021.12","url":null,"abstract":"Background: Rhinoviruses (RVs) represent the most important aetiological agents of the common cold and are responsible for about two-thirds of acute exacerbations of chronic bronchitis, asthma, and chronic obstructive pulmonary disease (COPD) in both children and adults. This study aimed to design a pan-serotypic vaccine capable of inducing cross-reactive antibodies against most of the RV by using a reverse Vaccinology approach. Methods: Bioinformatics analysis was carried out to characterise the capsid proteins (VP1, VP2, VP3, and VP4) of all known RV serotypes and to predict potential immune motifs. Conserved motifs consisting at least nine-mers common across all RV-A or B serotypes were selected and synthesized chemically. Four tagged full-length genes coding the capsid proteins of an ideal strain (HRV-74), VP1, VP2, VP3, and VP4 were constructed and cloned in vitro. Upon expression , the purified recombinant proteins were also administered subcutaneously to other groups of rabbits. The responses and cross-reactivity of the specific immunoglobulin M (IgM) and G (IgG) to the peptides, proteins, and whole viruses were measured. Results: The obtained anti-peptide antibodies exhibited a cross-neutralizing activity for different RV strains in vitro. Antibodies raised to the synthetic peptides exhibited cross-reactivity against the corresponding recombinant proteins and antigenically distinct RV strains coated on plates via ELISA assay. Conclusions: The study findings indicated that the peptides corresponding to the conserved region of the RV capsid proteins were potent immunogenic; moreover, the findings showed that their combination was crucial for extending the cross-protection against variant RVs.","PeriodicalId":8689,"journal":{"name":"Avicenna Journal of Clinical Microbiology and Infection","volume":"130 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76561989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}