Antibacterial Potential of Biosynthesized Silver Nanoparticles Using Berberine Extract Against Multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa.

The emergence of multidrug resistance in bacterial infections has limited the use of antibiotics. Helping the action of antibiotics is one of the needs of the day. Today, the biosynthesis of nanoparticles (NPs) is considered due to its safety and cost-effectiveness. In this study, we investigated the effect of biosynthesized silver nanoparticles (AgNPs) by Berberine plant extract against standard strains of multidrug-resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa. Utilized UV-Vis, FTIR, FESEM/EDX, XRD, DLS, and Zeta potential techniques to confirm the biosynthesis of NPs. Then, disk diffusion agar (DDA) and minimum inhibitory concentration (MIC) tests were performed using common classes of standard antibiotics and AgNPs on the mentioned bacteria. The synergistic action between AgNPs and antibiotics was evaluated by the checkerboard method. First, we obtained the confirmation results of the biosynthesis of AgNPs. According to the DDA test, both standard bacterial strains were sensitive to NPs and had an inhibition zone. Also, the MIC values showed that AgNPs inhibit the growth of bacteria at lower concentrations than antibiotics. On the other hand, the results obtained from checkerboard monitoring showed that AgNPs, in combination with conventional antibiotics, have a synergistic effect. The advantage of this study was comparing the antibacterial effect of AgNPs alone and mixed with antibiotics. The antibacterial sensitivity tests indicated that the desired bacterial strains could not grow even in low concentrations of AgNPs. This property can be applied in future programs to solve the drug resistance of microorganisms in bacterial diseases. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01136-y.

Comparing self-medication and medical supervised treatment before hospitalization among patients with Covid-19: A retrospective case-control study.

BACKGROUND: During the Covid-19 pandemic, there has been a notable increase in self-medication with antibiotics or other medications due to impaired access to healthcare services. This kind of self-treatment, without comprehending the condition and its related risks, can result in misdiagnosis, overdosing and delaying in acquiring professional medical attention, or may even cause antimicrobial resistance. Additionally, reports have suggested that medical practitioners have prescribed medications inappropriately to patients with Covid-19. To investigate this further, this study compared the medications used by patients with Covid-19 prior to hospitalization with or without a medical recommendation. METHODS: Data was extracted a mass survey of patients with of Covid-19 in Mashhad, and the patients were divided into two main groups: those who received medication with guidance from a medical professional (treatment group) and those who self-administered medications without professional oversight (self-treatment group). Statistical analysis was then conducted using SPSS version 26, the Chi-square, and multiple logistic regression test. RESULTS: This study examined 3266 patients, with 1466 included in the analysis. Results showed that men (9.5 %), those living in rural areas (21 %), and those with no academic degree (37.5%) had a higher likelihood to self-medicating. Antibiotics were the most frequently used medications prior to hospitalization (9.5%). Comparing the two groups revealed that three drug categories- antibiotics, antivirals and other medications (medicines that are not in the other 4 main categories)- were utilized more often in the treatment group than in the self-treatment group, with a p-value of < 0.05. The only medical condition that had a significant difference between the two groups was diabetes, with 34.1 % in the self-treatment group versus 24.5 % in the treatment group (P < 0.05). CONCLUSIONS: The Covid-19 pandemic has caused a surge in the inappropriate use of certain medications through self-medicating. This poses a serious risk to the health of patients, highlighting the need for not only adjusting guidelines but also raising awareness and enforcing compliance to prevent unnecessary use of drugs.

Novel approaches to overcome Colistin resistance in Acinetobacter baumannii: Exploring quorum quenching as a potential solution.

Acinetobacter baumannii is responsible for a variety of infections, such as nosocomial infections. In recent years, this pathogen has gained resistance to many antibiotics, and thus, carbapenems were used to treat infections with MDR A. baumannii strains in clinical settings. However, as carbapenem-resistant isolates are becoming increasingly prevalent, Colistin is now used as the last line of defense against resistant A. baumannii strains. Unfortunately, reports are increasing on the presence of Colistin-resistant phenotypes in infections caused by A. baumannii, creating an urgent need to find a substitute way to combat these resistant isolates. Quorum sensing inhibition, also known as quorum quenching, is an efficient alternative way of reversing resistance in different Gram-negative bacteria. Quorum sensing is a mechanism used by bacteria to communicate with each other by secreting signal molecules. When the population of bacteria increases and the concentration of signal molecules reaches a certain threshold, bacteria can implement mechanisms to adapt to a hostile environment, such as biofilm formation. Biofilms have many advantages for pathogens, such as antibiotic resistance. Different studies have revealed that disrupting the biofilm of A. baumannii makes it more susceptible to antibiotics. Although very few studies have been conducted on the biofilm disruption through quorum quenching in Colistin-resistant A. baumannii, these studies and similar studies bring hope in finding an alternative way of treating the Colistin-resistant isolates. In conclusion, quorum quenching has the potential to be used against Colistin-resistant A. baumannii.

A Comparative Study on Visual Detection of Mycobacterium tuberculosis by Closed Tube Loop-Mediated Isothermal Amplification: Shedding Light on the Use of Eriochrome Black T.

Loop-mediated isothermal amplification is a promising candidate for the rapid detection of Mycobacterium tuberculosis. However, the high potential for carry-over contamination is the main obstacle to its routine use. Here, a closed tube LAMP was intended for the visual detection of Mtb to compare turbidimetric and two more favorable colorimetric methods using calcein and hydroxy naphthol blue (HNB). Additionally, a less studied dye (i.e., eriochrome black T (EBT)) was optimized in detail in the reaction for the first time. Mtb purified DNA and 30 clinical specimens were used to respectively determine the analytical and diagnostic sensitivities of each method. The turbidimetric method resulted in the best analytical sensitivity (100 fg DNA/reaction), diagnostic sensitivity and specificity (100%), and time-to-positivity of the test (15 min). However, this method is highly prone to subjective error in reading the results. Moreover, HNB-, calcein-, and EBT-LAMP could respectively detect 100 fg, 1 pg, and 1 pg DNA/reaction (the analytical sensitivities) in 30, 15, and 30 min, while the diagnostic sensitivity and specificity were respectively 93.3% and 100% for them all. Interestingly, EBT-LAMP showed the lowest potential for subjective error in reading the results. This report helps judiciously choose the most appropriate visual method, taking a step forward toward the field applicability of LAMP for the detection of Mtb, particularly in resource-limited settings.

Clinical Evaluation of Commercial HARDSON COVID-19 Antigen Rapid Test Kit for Routine COVID-19 Diagnosis.

Objective: This study aimed to evaluate the sensitivity, specificity, and accuracy of the commercial HARDSON COVID-19 Antigen Rapid Test Kit for diagnosing COVID-19 among the Iranian population by compared with the results of commercial RT-PCR. Materials and Methods: Two nasopharyngeal swabs were collected from each patient. One swab was tested with HARDSON COVID-19 Antigen Rapid Test Kit, and the second swab was placed in 3 mL of a virus-transmitted inactivated media for RT-PCR testing. Then, the results of both tests were compared to investigate the diagnostic accuracy of the rapid antigen test. Results: A total of 275 suspected COVID-19 patients' samples were collected to investigate the diagnostic accuracy of HARDSON COVID-19 Antigen Rapid Test Kit. In this study, 162 positive and 113 negative samples were evaluated. As a result, the sensitivity, specificity, and accuracy of HARDSON COVID-19 Antigen Rapid Test Kit were 90%, 100%, and 94%, respectively. Conclusion: The diagnostic kit analyzed in this study indicated excellent specificity and a relatively good overall sensitivity for the diagnosis of COVID-19 when compared with the RT-PCR detection kit. Based on the result of this study, COVID-19 Antigen Rapid Test Kit indicated a good sensitivity (96%) in low cycle threshold (Ct) value, and it would be recommended to be integrated into routine diagnostic laboratories and used as an at-home rapid antigen test.

Assessment of antibiotic resistance changes during the Covid-19 pandemic in northeast of Iran during 2020-2022: an epidemiological study.

BACKGROUND: The coronavirus disease 2019 seems to change antibiotic resistance pattern. Certain conditions in the Covid-19 era may be contributing to the rise of antimicrobial resistance (AMR). Due to the limited information on the impact of Covid-19 on antimicrobial resistance (AMR), the purpose of this research was to investigate the trend in antimicrobial resistance changes of E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii in Hasheminezhad hospital. This hospital was a Corona center in Mashhad at the onset of this epidemic. METHODS: 1672 clinical samples were collected between January 21, 2020 and January 30, 2022from patients hospitalized at Hasheminezhad Hospital in Mashhad, Conventional microbiological procedures for identifying gram-negative bacteria and antibiotic susceptibility testing were used, according to the clinical and laboratory standards institute (CLSI) 2021. The two years of the pandemic, from the initial stage of the outbreak until the 6th peak, (January 2020 to and January 2022) were divided into 9 periods according to the seasons. RESULTS: Highest resistance rates were seen in E. coli (615 samples), K. pneumoniae (351 samples), P. aeruginosa (362 samples) and A. baumannii (344 samples) to Ampicillin (89.6%), Ampicillin (98%), Imipenem (91.8%), and Ceftazidime (94.6%), respectively. The largest change in antibiotic resistance was seen between Summer 2020 and Summer 2021 for K. pneumoniae with about a 30% rise in antibiotic resistance to Ceftriaxone. CONCLUSIONS: All 4 species evaluated in this study, have shown rising AMR rates during the first year of the pandemic in the northeast of Iran. This study revealed that E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii strains in Northern Iran have a higher level of antibiotic resistance than what was measured in similar studies conducted before the pandemic. This will further restrict treatment choices and jeopardize global public health.

A New Specific DNA Target Sequence for Identification of Staphylococcus epidermidis using Modified Comparative Genomic Analysis.

Background: Staphylococcus epidermidis (S. epidermidis) is the most frequently isolated pathogen from prostheses infections in the body. Therefore, improving its diagnostic methods, including rapid Nucleic Acid Amplification Tests (NAAT), seems necessary. Since the first step in designing a NAAT is to find a specific sequence and all DNA targets that have been introduced so far are not completely specific, we introduced a new 100% specific DNA target sequence to identify S. epidermidis in this study. Methods: Modified comparative genomic analysis was used to find the best specific target sequence to detect S. epidermidis. A PCR method was designed for the evaluation of this target. To determine the detection limit and analytical specificity, pure genomic DNA of 18 bacteria include 12 standard strains (one S. epidermidis and 11 non-S. epidermidis) and six clinical isolates (five S. epidermidis and one non-S. epidermidis) were used. Results: The 400 bp sequence of S. epidermidis ATCC 14990 was identified as the most specific sequence (Se400), having a 100% sequence similarity to S. epidermidis genomes but not with other bacteria. The detection limit of Se400-PCR was 10 fg, equal to about 4 copies of S. epidermidis genomic DNA/µl. All pure DNA templates from S. epidermidis generated a detectable amplicon by 264 bp length, but the PCR test was negative for the non-S. epidermidis group. Conclusion: The Se400 sequence can be considered as a specific target for detecting S. epidermidis, based on our findings.

Antimicrobial Peptides as a Promising Therapeutic Strategy for Neisseria Infections.

Antibiotic resistance is already widespread in the world, and it has become a great health problem. Therefore, comprehensive efforts are needed to minimize the resistance. The exploration of alternative therapies may offer a more targeted approach with less susceptibility to resistance. Even though antimicrobial peptides (AMPs) have been introduced as emerging antibiotic sources, they are not widely discussed in the literature. Since Neisseria infections show resistance to different types of antibiotics, the purpose of this review was to discuss the currently investigated AMPs with anti-Neisseria properties. In the present review, we provide an overview of 24 AMPs with in vitro anti-Neisseria properties.

The first diagnostic test for specific detection of Mycobacterium simiae using an electrochemical label-free DNA nanobiosensor.

Mycobacterium simiae has been reported to be the most prevalent species of Nontuberculous mycobacteria (NTM) in many countries. As both phenotypic and molecular detection of M. simiae and other NTMs have limitations, finding an accurate, fast, and low-cost diagnostic method is critical for the management of infections. Here, we report the development of a new type of label-free electrochemical biosensor using a gold electrode decorated with l-cysteine/PAMAM dendrimer for specific targeting of M. simiae ITS sequence. DNA hybridization was monitored by measuring changes in the free guanine electrical signal with changing ssDNA target concentrations by differential pulse voltammetry (DPV) method. Response surface methodology (RSM) was applied for the optimization of variables affecting biosensor response. Under optimal conditions, the biosensor revealed a wide linear range from 10-14 M to 10-6 M and a detection limit of 1.40 fM. The fabricated biosensor showed an excellent selectivity to M. simiae in the presence of other similar pathogenic bacteria. Moreover, experimental results confirmed that this biosensor exhibited great precision and high reproducibility, hence provides a low-cost, label-free, and faster detection analysis, representing a novel strategy in detecting other NTMs.

Nanotechnology-driven advances in the treatment of diabetic wounds.

Diabetic foot ulcers (DFUs) are chronic severe complications of diabetes disease and remain a worldwide clinical challenge with social and economic consequences. Diabetic wounds can cause infection, amputation of lower extremities, and even death. Several factors including impaired angiogenesis, vascular insufficiency, and bacterial infections result in a delayed process of wound healing in diabetic patients. Treatment of wound infections using traditional antibiotics has become a critical status. Thus, finding new therapeutic strategies to manage diabetic wounds is urgently needed. Nanotechnology has emerged as an efficient approach for this purpose. This review aimed to summarize recent advances using nanotechnology for the treatment of diabetic wounds.

Synergistic effect of two antimicrobial peptides, Nisin and P10 with conventional antibiotics against extensively drug-resistant Acinetobacter baumannii and colistin-resistant Pseudomonas aeruginosa isolates.

BACKGROUND: Infections caused by drug-resistant strains of Acinetobacter baumannii and Pseudomonas aeruginosa are now a global problem that requires the immediate development of new antimicrobial drugs. Combination therapy and using antimicrobial peptides are two strategies with high potential to solve this issue. By these strategies, this study aimed to determine the antimicrobial effect of Nisin and P10 antimicrobial peptides on extensively drug-resistant Acinetobacter baumannii and colistin-resistant Pseudomonas aeruginosa isolates, and investigate the most effective combination of an antimicrobial peptide with an antibiotic. MATERIAL AND METHODS: This study was performed on five resistant clinical isolates and one standard strain for each kind of bacterium. First, the minimum inhibitory concentrations of two antimicrobial peptides (Nisin and P10) and five common antibiotics for the treatment of Gram-negative bacteria (ceftazidime, tobramycin, ciprofloxacin, doripenem, and colistin) was determined using Scanner-Assisted Colorimetric MIC Method. Then, the combination effect of P10+Nisin, P10+antibiotics, Nisin + antibiotics was investigated using checkerboard method. RESULTS: The MIC value of Nisin and P10 against studied pathogens were 64-256 and 8-32 µg/ml, respectively. P10+Nisin combination showed synergistic effect against standard strains and additive effect against drug-resistant clinical isolates. It was also found that the combination effect of P10+ceftazidim, P10+doripenem, and Nisin + colistin was synergistic in most cases. Nisin + tobramycin combination showed synergistic effect in exposure to standard strains, while the synergy is strain-dependent against drug-resistant clinical isolates. CONCLUSION: In conclusion, the synergism of Nisin + colistin and P10+ceftazidime/doripenem could be of great therapeutic value as antimicrobial drugs against infections caused by colistin-resistant P.aeruginosa and XDR A. baumannii.

COVID-19 target: A specific target for novel coronavirus detection.

An ongoing outbreak of pneumonia associated with a novel coronavirus has been reported worldwide and become a global health problem; hence, the diagnosis and differentiation of this virus from other types of coronavirus is essential to control of the disease. To this end, the analysis of genomics data plays a vital role in introducing a stronger target and consequently provides better results in laboratory examinations. The modified comparative genomics approach helps us to find novel specific targets by comparing two or more sequences on the nucleotide collection database. We, for the first time, detected ORF8 gene as a potential target for the detection of the novel coronavirus. Unlike previous reported genes (RdRP, E and N genes), ORF8 is entirely specific to the novel coronavirus (COVID-19) and has no cross-reactivity with other kinds of coronavirus. Accordingly, ORF8 gene can be used as an additional confirmatory assay.

Construction, Cloning, and Expression of CagA Recombinant Protein of Helicobacter pylori.

BACKGROUND: This study aimed to assess construction and expression of CagA recombinant protein of Helicobacter pylori (H. pylori) in Escherichia coli (E. coli) BL21. METHODS: Bioinformatics was used in designing the desired gene by Gene Runner. Next, the construct was subcloned to pET21b vector and this process was confirmed by Polymerase Chain Reaction (PCR), enzyme digestion and sequencing techniques. Then, it was cloned in the Escherichia coli BL21 as an expression host. Expression of protein was verified using sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting technique. For purification of the protein, the Ni-NTA column was used. Protein concentration was determined by the Bicinchoninic Acid Protein Assay Kit (Parstoos). Finally, Western blotting was performed using CagA antibodies and normal human serum for determining immunogenicity feature with human antiserum. RESULTS: According to the results of the present study, CagA construct was cloned into the pET21b vector and after confirmation and cloning in host expression, recombinant protein with the size of 38 kDa was successfully expressed and purified. The recombinant CagA protein showed immunogenicity characteristics with human antiserum. CONCLUSION: In conclusion, only 5'-end of recombinant protein CagA with high immunogenicity effects was successfully constructed, cloned and expressed. Also, CagA recombinant protein showed good immunogenicity activity with human antiserum.

Antimicrobial peptides as a promising treatment option against Acinetobacter baumannii infections.

BACKGROUND: With the increasing rate of antibiotic resistance in Acinetobacter, the World Health Organization introduced the carbapenem-resistant isolates in the priority pathogens list for which innovative new treatments are urgently needed. Antimicrobial peptides (AMPs) are one of the antimicrobial agents with high potential to produce new anti-Acinetobacter drugs. This review aims to summarize recent advances and compare AMPs with anti-Acinetobacter baumannii activity. METHODS: Active AMPs against Acinetobacter were considered, and essential features, including structure, mechanism of action, anti-A. baumannii potent, and other prominent characteristics, were investigated and compared to each other. In this regard, the Google Scholar search engine and databases of PubMed, Scopus, and Web of Science were used. RESULTS: Forty-six anti-Acinetobacter peptides were identified and classified into ten groups: Cathelicidins, Defensins, Frog AMPs, Melittin, Cecropins, Mastoparan, Histatins, Dermcidins, Tachyplesins, and computationally designed AMPs. According to the Minimum Inhibitory Concentration (MIC) reports, six peptides of Melittin, Histatin-8, Omega76, AM-CATH36, Hymenochirin, and Mastoparan have the highest anti-A. baumannii power against sensitive and antibiotic-resistant isolates. All anti-Acinetobacter peptides except Dermcidin have a net positive charge. Most of these peptides have alpha-helical structure; however, ß-sheet and other structures have been observed among them. The mechanism of action of these antimicrobial agents is divided into two categories of membrane-based and intracellular target-based attack. CONCLUSION: Evidence from this review indicates that AMPs would be likely among the main anti-A. baumannii drugs in the post-antibiotic era. Also, the application of computer science to increase anti-A. baumannii activity and reduce toxicity could be helpful.

Pulmonary Nocardiosis in Suspected Tuberculosis Patients: A Systematic Review and Meta-Analysis of Cross-Sectional Studies.

BACKGROUND: nocardiosis is an opportunistic infectious disease in immunocompromised patients. The most common form of nocardiosis infection in humans is pulmonary nocrdiosis caused by inhaling Nocardia species from the environment. Thus, this study aimed to evaluate the pulmonary nocardiosis in patients with suspected tuberculosis using systematic review and meta-analysis. METHODS: We conducted a systematic search for cross-sectional studies focused on the pulmonary nocardiosis among patients with pulmonary tuberculosis based on the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) published from January 2001 to October 2019. The search was conducted in MEDLINE/PubMed, Web of Science, Scopus, Cochrane Library, Google Scholar, Science Direct databases, and Iranian databases. Medical subject headings (MeSH) and text words were searched: "pulmonary nocardiosis", "nocardiosis", OR "nocardial infection", "pulmonary nocardial infections/agents", AND "pulmonary tuberculosis", OR "pulmonary TB", AND "Iran". Two of the reviewers enrolled independently articles published in English and Persian languages according to the inclusion and the exclusion criteria. Comprehensive Meta-Analysis software (Version 3.3.070) was used for meta-analysis. RESULTS: Only 4 studies met the eligibility criteria. The pulmonary nocardiosis prevalence varied from 1.7% to 6.7%. The combined prevalence of nocardiosis among patients with suspected pulmonary tuberculosis in Iran was 4.8% (95% CI: 3-7.3, Q=5.8, Z=12.7). No heterogeneity was observed between studies because I2 was 48.3. N. cyriacigeorgica and N. asteroides were reported as the prevalent isolates, respectively. CONCLUSIONS: This review showed in patients suspected TB when they were negative in all diagnosis laboratory tests, nocardiosis cases which be considered.

Epinecidin-1, a highly potent marine antimicrobial peptide with anticancer and immunomodulatory activities.

BACKGROUND: Antibiotic-resistant pathogens are an emerging threat in this century. Epinecidin-1 is a multi-functional Antimicrobial Peptide (AMP) produced by Orange-spotted grouper (Epinephelus coioides) has been shown to have extensive potentials as an alternative for current antibiotics. Due to the huge costs for the study and the production of a new drug, if an antimicrobial peptide has other beneficial functions in addition to antimicrobial activities, it would be preferred. METHODS: In this study, properties and applications of Epinecidin-1 were investigated and addressed comprehensively. To achieve this, the Google Scholar search engine and three databases of PubMed, Scopus, and Web of Science were used. RESULTS: Epinecidin-1 is a cationic AMP with an alpha-helical structure. Seven functional usages of this peptide have been reported in the literature including antibacterial, antifungal, antiviral, antiprotozoal, anticancer, immunomodulatory, and wound healing properties. Moreover, this peptide has high potential to be used as an active ingredient in cleaning solutions as well as application in vaccine production. CONCLUSION: Due to significant antimicrobial activities tested on bacteria such as Staphylococcus aureus and Helicobacter pylori and also wound healing properties, Epi-1 has high potential to be considered as an important candidate for the production of new drugs and treatment of various infections including diabetic foot ulcer and peptic ulcer. Moreover, adjuvant-like properties of Epi-1 make it a suitable candidate for the studies related to an adjuvant. Other attractive properties such as anticancer effects have also been reported for this peptide which encourages further studies on this peptide.

The short-chain dehydrogenases/reductases (SDR) gene: A new specific target for rapid detection of Mycobacterium tuberculosis complex by modified comparative genomic analysis.

BACKGROUND: Early detection of tuberculosis is one of the crucial steps for TB control. Although, the sensitivity of conventional methods like Lowenstein Jensen (LJ) culture and direct staining is quite low, molecular techniques like polymerase chain reaction (PCR) are more sensitive and be considered as useful tools for rapid detection of tuberculosis. Various genes like IS6110 and mpb64 have been used as target for detection of M. tuberculosis, but more research is needed to find the most specific targets. The short-chain dehydrogenases/reductases family (SDR) is one of a very large family of NAD- or NADP-dependent oxidoreductase enzymes which is present in all M. tuberculosis strains. The large part of SDR sequences in tuberculosis is completely conserved and different from non-tuberculosis mycobacterium. The aim of the study was to develop an in-house PCR assay using the SDR target for rapid detection of M. tuberculosis from clinical specimens. METHOD: M. tuberculosis-specific sequences were found using modified genome comparison method and the primers were designed by the Primer Premier 5.0 software. A PCR assay was developed targeting the nucleotide sequences within the SDR gene. A total of 50 cultivated specimens and 120 clinical specimens were evaluated by PCR. RESULTS: The clinical evaluation of SDR PCR assay showed high specificity (100%) and high sensitivity (88.5%). The analytical sensitivity was 10 fg of template DNA which is theoretically equivalent to 2 copy of genomic DNA per microliter. The SDR is a new specific target of M. tuberculosis and no cross-reactivity was observed to non-tuberculosis mycobacterium and other pathogenic bacteria. CONCLUSIONS: Based on our results, the SDR gene can be considered as a useful target for detection of M. tuberculosis complex from clinical specimens.

Review of antimicrobial peptides with anti-Helicobacter pylori activity.

BACKGROUND: The emergence of antibiotic-resistant Helicobacter pylori strains in recent years has increased the need for finding an alternative in the post-antibiotic era. One of the fields being considered for this purpose is antimicrobial peptides. The aim of this review was to provide an obvious scheme from the studied anti-H. pylori peptides and to investigate their common features. METHOD: First, all of the antimicrobial peptides with their anti-H. pylori effects have been proved up to September 2018 were selected and their information including structure, mechanism of action, and function was reviewed. To achieve this, three databases of PubMed, Scopus, and Web of science were used. RESULTS: A total of 9 groups containing 22 antimicrobial peptides were found with demonstrated anti-H. pylori effects. The nine groups included pexiganan, tilapia piscidins, epinecidin-1, cathelicidins, defensins, bicarinalin, odorranain-HP, PGLa-AM1, and bacteriocins. Most of the antimicrobial peptides, not all, had common features such as the ability to kill antibiotic-resistant strains, having α-helical structure, being cationic, with high positive charge and isoelectric point. CONCLUSION: Antimicrobial peptides with anti-H. pylori effects have the potential to replace the antibiotics, especially in the post-antibiotic era, if a rapid and low-cost production method would be found.

Modified genome comparison method: a new approach for identification of specific targets in molecular diagnostic tests using Mycobacterium tuberculosis complex as an example.

BACKGROUND: The first step of designing any genome-based molecular diagnostic test is to find a specific target sequence. The modified genome comparison method is one of the easiest and most comprehensive ways to achieve this goal. In this study, we aimed to explain this method with the example of Mycobacterium tuberculosis complex and investigate its efficacy in a diagnostic test. METHODS: A specific target was identified using modified genome comparison method and an in-house PCR test was designed. To determine the analytical sensitivity and specificity, 10 standard specimens were used. Also, 230 specimens were used to determine the clinical sensitivity and specificity. RESULTS: The identity and query cover of our new diagnostic target (5KST) were ≥ 90% with M. tuberculosis complex. The 5KST-PCR sensitivity was 100% for smear-positive, culture-positive and 85.7% for smear-negative, culture-positive specimens. All of 100 smear-negative, culture-negative specimens were negative in 5KST-PCR (100% clinical specificity). Analytical sensitivity of 5KST-PCR was approximately 1 copy of genomic DNA per microliter. CONCLUSIONS: Modified genome comparison method is a confident way to find specific targets for use in diagnostic tests. Accordingly, the 5KST-PCR designed in this study has high sensitivity and specificity and can be replaced for conventional TB PCR tests.

Potent and selective inhibitors of class A ß-lactamase: 7-prenyloxy coumarins.

Class A and D ß-lactamases are the main causes of resistance against ß-lactam antibiotics, especially the penam group, in Staphylococcus aureus. On the basis of the potentiator property of ethanolic extracts of Ferula szowitsiana root on penicillin, MIC values observed for resistant S. aureus, the main naturally occurring compounds in these extracts, auraptene, umbelliprenin and galbanic acid, were evaluated for ß-lactamase inhibitory activity. Amongst them auraptene showed the most potent inhibitory activity (IC50=21±1.5 µM) toward class A ß-lactamase, whereas no inhibition was observed for class D ß-lactamase. To obtain the structure activity relationship of the mentioned compounds and rationalize the enzyme inhibitory results, docking analysis was performed for both groups of ß-lactamases. Docking analysis showed that the compounds have 100-500-fold lower bonding affinity toward the class D ß-lactamase than toward the class A enzyme.