Effects of non-tuberculous mycobacteria on BCG vaccine efficacy: A narrative review.

The Mycobacterium tuberculosis bacterial pathogen is responsible for the ongoing global tuberculosis (TB) epidemic. Bacille Calmette-Guérin (BCG), the only currently approved TB vaccine, is successful in preventing disseminated disease in newborns. However, it has a variable efficacy against pulmonary TB in adults. This protective effect of the vaccine varies greatly among different populations and geographical areas, which the increased exposure of particular populations to non-tuberculous mycobacteria (NTM) is considered as one of the reasons for this issue. Numerous studies have shown that exposure to NTM species causes the host immune system to be improperly primed. It has also been suggested that NTM species may be blamed for reduction in BCG vaccine effectiveness against M. tuberculosis. The increased exposure of certain populations to NTM has diverse effects on BCG efficacy. Moreover, the exposure to NTM can induce opposite effects on BCG efficacy depending on the NTM exposure route and survivability. A detailed understanding of the impact of NTM exposure on the efficacy of the BCG vaccine is essential for ongoing efforts to develop new TB vaccines as it may ultimately be a crucial success factor. The aim of this study was to review the findings of the studies focusing on the effects of NTM on BCG vaccine efficacy in animal models.

Prevalence of linezolid resistance in Streptococcus pneumoniae isolates: a systematic review and meta-analysis.

Aim: This study aimed to understand the current level of linezolid (LNZ) resistance in Streptococcus pneumoniae isolates reported over the past 10 years. Material & methods: An electronic search was conducted for the following keywords: ((Streptococcus pneumoniae [title/abstract]) OR (Pneumococcus [title/abstract]) OR (Pneumococci [title/abstract]) AND (linezolid [title/abstract]) OR (Zyvox [title/abstract])) OR (Zyvoxid [title/abstract])). Result: Out of all the studies, 80 had a cross-sectional design, while 11 followed a cohort approach. The prevalence of LNZ resistance among S. pneumoniae isolates ranged from 0% to 4.86%. Discussion: Urgent, high-powered, randomized, controlled trials with participants from endemic regions are needed to gain a comprehensive understanding of the impact on and significance of LNZ treatment to patients.

Mechanism of action, resistance, interaction, pharmacokinetics, pharmacodynamics, and safety of fostemsavir.

The Food and Drug Administration (FDA) has licensed many antiretroviral medications to treat human immunodeficiency virus type 1 (HIV-1), however, treatment options for people with multi-drug resistant HIV remain limited. Medication resistance, undesirable effects, prior tolerance, and previous interlacement incapacity to deliver new drug classes all lead to the requirement for new medication classes and drug combination therapy. Fostemsavir (FTR) is a new CD-4 attachment inhibitor medicine that was recently authorized by the United States FDA to treat HIV-1. In individuals with multidrug-resistant (MDR) HIV-1, FTR is well tolerated and virologically active. According to recent investigations, drug combination therapy can positively affect MDR-HIV. The mechanism of action, resistance, interaction, pharmacokinetics, pharmacodynamics, and safety of FTR has been highlighted in this review.

Epidemiology of HBV-HCV Coinfection Among Iranian Patients: a Systematic Review and Meta-Analysis.

INTRODUCTION: Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are major causes of hepatitis, an important disease affecting millions of people worldwide. The present study aimed to estimate the prevalence of HBV-HCV coinfection in Iran and evaluate the demographic and behavioral factors associated with a heterogeneity of results. METHODS: We used MEDLINE/PubMed, Web of Science, SCOPUS, Google Scholar, and 1 Persian database (Scientific Information Database) for a systematic search from January 1, 2005 to February 26, 2022. Data were analyzed based on the city, publication time, enrollment time, number of patients, gender, mean age, and HBV/HCV diagnosis method. The analysis was carried out using R (version 4.2.1) and the metafor package (version 3.8.1). RESULTS: In total, 2,072 studies were found through databases: PubMed/Medline (n = 224), Scopus (n = 1,092), Web of Science (n = 394), Google Scholar (n = 272), and Scientific Information Database (n = 90). Overall, nine studies with 1,964 male and 1,909 female patients (age average = 38.1) were included in the analysis. The observed proportion ranged from 0.004 to 0.273. The estimated average proportion was µ = 0.040 (95% CI: 0.016 to 0.101). Therefore, the average outcome differed significantly from zero (z = -6.330, p < 0.001). CONCLUSIONS: HBV/HCV coinfection is a challenging and crucial medical condition because of its variable clinical manifestations, increased risk of cirrhosis and HCC, and unpredictable treatment response. There is a heterogeneous distribution pattern of HBV/HCV infection between Iran's provinces, indicating the necessity of continuous prevention and control measurements and the implementation of further epidemiologic studies for collecting reliable data on HBV/HCV prevalence in different parts of Iran.

Evaluating the incidence of ampC-ß-lactamase genes, biofilm formation, and antibiotic resistance among hypervirulent and classical Klebsiella pneumoniae strains.

AIM: Both immunocompetent and healthy individuals can become life-threateningly ill when exposed to the hypervirulent (hvKp) strains of Klebsiella pneumoniae (Kp). The main objectives of this study were to evaluate the presence of ampC-lactamase genes, biofilm formation, and antibiotic resistance in clinical strains of hvKp and cKp (classical K. pneumoniae). MATERIALS AND METHODS: Kp strains were collected from patients referred to Shahidzadeh Hospital in Behbahan City, Khuzestan Province, Iran. Several techniques were used to identify hvKp. The hypermucoviscosity phenotype was determined using the string test. Isolates that developed dark colonies on tellurite agar were assumed to be hvKp strains. If any of the iucA, iutA, or peg-344 genes were detected, the isolates were classified as hvKp. Phenotypic and genotypic detection of AmpC ß-lactamases of hvKp strains was performed by the combined disk method and polymerase chain reaction, respectively. In addition, crystal violet staining was used to determine the biofilm formation of these isolates. RESULTS: For this study, 76 non-duplicative isolates of Kp were collected. Overall, 22 (28.94%) strains had positive string test results, and 31 (40.78%) isolates were grown in tellurite-containing medium. The genes iucA and iutA or peg-344 were found in 23.68% of all Kp strains and in 50% of tellurite-resistant isolates, respectively. The most effective antibiotics against hvKp isolates were tetracycline (85.52%) and chloramphenicol (63.15%). Using the cefoxitin disc diffusion method, we observed that 56.57% (43/76) of the strains were AmpC producer. A total of 30.26% (n = 23/76) of the isolates tested positive for at least one ampC gene, including blaDHA (52.63%, n = 40), blaCIT (40.78%, n = 31), blaACC (19.76%, n = 15), blaMOX (25%, n = 19), and blaFOX (43.42%, n = 33). Biofilm formation analysis revealed that most hvKp isolates were weak (n = 6, 40%) and moderate (n = 5, 33.33%) biofilm producers. CONCLUSION: Healthcare practitioners should consider the possibility of the existence and acquisition of hvKp everywhere. The exact mechanisms of bacterial acquisition are also unknown, and it is unclear whether the occurrence of infections is related to healthcare or not. Thus, there are still many questions about hvKp that need to be investigated.

The global prevalence of gastric cancer in Helicobacter pylori-infected individuals: a systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori is a gastrointestinal pathogen that infects around half of the world's population. H. pylori infection is the most severe known risk factor for gastric cancer (GC), which is the second highest cause of cancer-related deaths globally. We conducted a systematic review and meta-analysis to assess the global prevalence of GC in H. pylori-infected individuals. METHODS: We performed a systematic search of the PubMed, Web of Science, and Embase databases for studies of the prevalence of GC in H. pylori-infected individuals published from 1 January 2011 to 20 April 2021. Metaprop package were used to calculate the pooled prevalence with 95% confidence interval. Random-effects model was applied to estimate the pooled prevalence. We also quantified it with the I2 index. Based on the Higgins classification approach, I2 values above 0.7 were determined as high heterogeneity. RESULTS: Among 17,438 reports screened, we assessed 1053 full-text articles for eligibility; 149 were included in the final analysis, comprising data from 32 countries. The highest and lowest prevalence was observed in America (pooled prevalence: 18.06%; 95% CI: 16.48 - 19.63; I2: 98.84%) and Africa (pooled prevalence: 9.52%; 95% CI: 5.92 - 13.12; I2: 88.39%). Among individual countries, Japan had the highest pooled prevalence of GC in H. pylori positive patients (Prevalence: 90.90%:95% CI: 83.61-95.14), whereas Sweden had the lowest prevalence (Prevalence: 0.07%; 95% CI: 0.06-0.09). The highest and lowest prevalence was observed in prospective case series (pooled prevalence: 23.13%; 95% CI: 20.41 - 25.85; I2: 97.70%) and retrospective cohort (pooled prevalence: 1.17%; 95% CI: 0.55 - 1.78; I 2: 0.10%). CONCLUSIONS: H. pylori infection in GC patients varied between regions in this systematic review and meta-analysis. We observed that large amounts of GCs in developed countries are associated with H. pylori. Using these data, regional initiatives can be taken to prevent and eradicate H. pylori worldwide, thus reducing its complications.

Fatal vanishing bile duct syndrome in Iranian patient with Hodgkin's lymphoma.

Vanishing bile duct syndrome (VBDS) has been postulated that may be related to Hodgkin's lymphoma (HL). In the present study, we present a 75-year-old male patient with HL who received chemotherapy but has not received any radiotherapy. The patient's condition worsened in further days, and he died with the diagnosis of cirrhosis and hepatic failure.

Global Estimate of Clarithromycin Resistance in Clinical Isolates of Helicobacter pylori: a Systematic Review and Meta-Analysis.

BACKGROUND: A high resistance rate to clarithromycin usually leads to failure to eradicate Helicobacter pylori. The aim of the present study was to review recent data on H. pylori resistance towards clarithromycin in clinical studies worldwide. METHODS: PubMed/Medline, Web of Science, and Embase were used for a systematic review from 1 January 2011 to 13 April 2021 to retrieve the clinical trial studies. Data were analyzed according to publication year, age, geographic area, and minimum inhibitory concentration (MIC). Statistical analysis was done by STATA version 14.0 (College Station, Texas). RESULTS: From a total of 4,304 articles, 89 articles related to clinical studies were selected for analysis. The overall H. pylori clarithromycin resistance rate was 34.95%. Based on continents, the highest and lowest pooled estimate of the bacterial resistance rates were observed in Asia (35.97%) and North America (7.02%), respectively. The highest and the lowest pooled estimate of H. pylori resistance rate to clarithromycin based on country were obtained in Australia (93.4%) and USA (7%), respectively. CONCLUSIONS: H. pylori resistance to clarithromycin in most parts of the world is more than 15%, so it is recommended that each country, after estimating the rate of resistance to clarithromycin, determine the treatment/eradication pattern for H. pylori infection.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis.

Background: Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics. Method: A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance. Results: The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I2 = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05). Conclusion: Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Ebanga™: The most recent FDA-approved drug for treating Ebola.

Ebolavirus (EBOV) is a virulent pathogen that causes Ebola virus disease (EVD), which is a life-threatening human condition with a fatality rate of up to 90%. Since the first outbreak in Africa in 1976, several outbreaks and epidemics of EBOV have occurred across the globe. While EVD is recognized as a serious threat to human health and outbreaks occur almost every year, the treatment options for the disease are limited. In designing therapeutic strategies against EBOV infection, viral structural proteins, such as glycoprotein (GP), could be an excellent target for neutralizing the virus. According to the latest research, GP-specific antibodies are the most efficient post-exposure treatments for EVD. Ansuvimab-zykl, i.e., mAb114 (Ebanga™), is a recent FDA-approved human immunoglobulin monoclonal antibody targeting EBOV GP. This review provides a brief overview of the pharmacological effects and safety profile of ansuvimab in clinical trials and provides insights into the precise mechanism of this new drug for treating EVD.

The potential role of telemedicine in the infectious disease pandemic with an emphasis on COVID-19: A narrative review.

Background and Aims: Due of its low cost, rapid speed, data record, and vast communication coverage, information and communication technology might be useful for health-related fields in times of crisis. By providing medical or hygienic services to a patient who lives elsewhere using communication methods like email, fax, cellphones, applications, and wireless gadgets, telemedicine can aid in the better management of diseases. Reviewing the potential role of telemedicine in the pandemic of infectious diseases with a focus on the Coronavirus disease 2019 (COVID-19) epidemic was the main goal of this study. Methods: "Google Scholar," "PubMed," "Science Direct," and "Scopus" databases were searched to collect the papers that identify the advantages and disadvantages of telemedicine in the disease pandemic. Searched keywords include: telepharmacy, telemedicine, remote communication, pandemic(s), epidemic, distant care, distant communication, phone consulation, video conference communication and patient education. Results: Information and communication technology are crucial, especially when dealing with pandemics of infectious diseases like COVID-19. Less "in-person" patient visits to hospitals as a result of telemedicine eventually means less labor for the medical staff, less viral exposure for patients, and ultimately less disease spread. By establishing a bidirectional reciprocal relationship between patients and healthcare providers although they are in separate geographical areas, it can improve patient health status. Conclusion: Governments are currently facing a significant budgetary burden because to the COVID-19 pandemic. Since patients are not sent to medical facilities in person, which could be a source of infection, telemedicine reduces disease spread while saving money.

Antimicrobial resistance and biofilm formation capacity among Acinetobacter baumannii strains isolated from patients with burns and ventilator-associated pneumonia.

BACKGROUND: Acinetobacter baumannii is a pathogen responsible for nosocomial infections, especially in patients with burns and ventilator-associated pneumonia (VAP). The aims of this study was to compare the biofilm formation capacity, antimicrobial resistance patterns and molecular typing based on PFGE (Pulsed-Field Gel Electrophoresis) in A. baumannii isolated from burn and VAP patients. MATERIALS AND METHODS: A total of 50 A. baumannii isolates were obtained from burn and VAP patients. In this study, we assessed antimicrobial susceptibility, biofilm formation capacity, PFGE fingerprinting, and the distribution of biofilm-related genes (csuD, csuE, ptk, ataA, and ompA). RESULTS: Overall, 74% of the strains were multidrug resistant (MDR), and 26% were extensively drug-resistant (XDR). Regarding biofilm formation capacity, 52%, 36%, and 12% of the isolates were strong, moderate, and weak biofilm producers. Strong biofilm formation capacity significantly correlated with XDR phenotype (12/13, 92.3%). All the isolates harbored at least one biofilm-related gene. The most prevalent gene was csuD (98%), followed by ptk (90%), ataA (88%), ompA (86%), and csuE (86%). Harboring all the biofilm-related genes was significantly associated with XDR phenotype. Finally, PFGE clustering revealed 6 clusters, among which cluster No. 2 showed a significant correlation with strong biofilm formation and XDR phenotype. CONCLUSION: Our findings revealed the variable distribution of biofilm-related genes among MDR and XDR A. baumannii isolates from burn and VAP patients. A significant correlation was found between strong biofilm formation capacity and XDR phenotype. Finally, our results suggested that XDR phenotype was predominant among strong-biofilm producer A. baumannii in our region.

Efficacy of drug regimen with and without oseltamivir in hospitalized patients with COVID-19: A retrospective study.

Introduction: Coronavirus disease 2019 (COVID-19) is the most critical issue in nowadays medicine. We aimed to evaluate the use and therapeutic outcomes of oseltamivir, an antiviral drug for patients with COVID-19. Materials and method: In an observational study conducted at Imam Khomeini Hospital in Amol, Iran, data for 544 patients with laboratory and CT scan result confirmed COVID-19 were retrospectively collected between February 24th and April 13th 2020. To compare the characteristics of patients based on gender, the chi-square test was used. Logistic regression was used to evaluate the effect of oseltamivir on the outcome of treatment. Logrank test were used to compare the length of hospital stay in people treated with oseltamivir and drugs other than oseltamivir. Results: Kaplan-Meier and logrank test showed no significant reduction in hospitalization time and survival rate following treatment with oseltamivir. However, a significant increase in lymphocytes count and reduction of C-reactive protein (CRP) level detected. Conclusion: Administration of oseltamivir for patients with COVID-19 didn't show any improvement in hospitalization duration and survival rate.

Introducción: la enfermedad por coronavirus 2019 (COVID-19) es el tema más crítico en la medicina actual. Nuestro objetivo fue evaluar el uso y los resultados terapéuticos de oseltamivir, un medicamento antiviral para pacientes con COVID-19. Materiales y método: en un estudio observacional realizado en el Hospital Imam Khomeini en Amol, Irán, los datos de 544 pacientes con resultados de laboratorio y tomografía computarizada confirmados de COVID-19 se recopilaron retrospectivamente entre el 24 de febrero y el 13 de abril de 2020. Para comparar las características de los pacientes en función del género se utilizó la prueba de chi-cuadrado. Se utilizó regresión logística para evaluar el efecto de oseltamivir en el resultado del tratamiento. Se utilizó la prueba de rango logarítmico para comparar la duración de la estancia hospitalaria en personas tratadas con oseltamivir y otros fármacos distintos del oseltamivir. Resultados: Kaplan­Meier y la prueba de rango logarítmico no mostraron una reducción significativa en el tiempo de hospitalización y la tasa de supervivencia después del tratamiento con oseltamivir. Sin embargo, se detectó un aumento significativo en el recuento de linfocitos y una reducción del nivel de proteína C reactiva (PCR). Conclusión: la administración de oseltamivir para pacientes con COVID-19 no mostró ninguna mejora en la duración de la hospitalización y la tasa de supervivencia.

Evaluating the characteristics of patients with SARS-CoV-2 infection admitted during COVID-19 peaks: A single-center study.

Background: Nowadays, the world is facing a coronavirus disease (COVID-19) pandemic, elicited by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). At the time of studying, five COVID-19 waves occurred in Iran. We aimed to evaluate the characteristics of patients with SARS-CoV-2 infection admitted to Vasei Hospital of Sabzevar, Iran during COVID-19 peaks. Methods: Clinical manifestations, laboratory findings, radiological findings, and underlying diseases of patients with COVID-19 were obtained from electronic medical records. Then, this information was compared in patients with SARS-CoV-2 infection to the peaks of COVID-19. Results: The highest and lowest respiratory involvements were observed in the third (74.6%) and fourth (38.8%) peaks, respectively. The most common radiological finding in all peaks was ground-glass opacity (28.98%), followed by consolidation, which was the highest (14.6%) in peak three. The lymphocyte count decreased in all peaks. Its highest reduction (16.12) occurred in the third peak. The SpO2 was lower than normal range in all peaks, except for the second (90.77%) and fifth (91.06%) peaks. Dyspnea (52.36%) was the most and dizziness (1.26%) and sore throat (0.6%) were the least frequent symptoms. The mortality rates were 14. 4%, 18.2%, 23%, 9.02%, and 9.4% in the first to fifth peaks, respectively. Conclusion: As different variants of the SARS-CoV-2 virus were predominant in each wave, COVID-19 patients had different features in various peaks. The fifth wave of COVID-19 had the highest number of hospitalized patients, while the first peak had the lowest number. Perhaps, the significant increase in testing capacity in the fifth wave and its long time period are the reasons for this growth. Most of the clinical symptoms were similar in all peaks, but the incidence was different. As patients hospitalized in the third peak had the highest rate of underlying disease, it can be a reason for the increase in the death rate of patients. We did not observe any significant differences in laboratory tests among the patients during different peaks. Thus, we should be vigilant in continuously studying the characteristics of the disease, and be able to modify treatments rapidly if necessary.

Antecedentes: Hoy en día, el mundo se enfrenta a una pandemia de enfermedad por coronavirus (COVID-19), provocada por el síndrome respiratorio agudo severo coronavirus 2 (SARS-CoV-2). En el momento del estudio, se produjeron cinco olas de COVID-19 en Irán. Nuestro objetivo fue evaluar las características de los pacientes con infección por SARS-CoV-2 ingresados en el Hospital Vasei de Sabzevar, Irán, durante los picos de COVID-19. Métodos: Las manifestaciones clínicas, los hallazgos de laboratorio, los hallazgos radiológicos y las enfermedades subyacentes de los pacientes con COVID-19 se obtuvieron de los registros médicos electrónicos. Luego, esta información se comparó en pacientes con infección por SARS-CoV-2 a los picos de COVID-19. Resultados: Las afectaciones respiratorias más altas y más bajas se observaron en el tercer (74,6%) y cuarto (38,8%) picos, respectivamente. El hallazgo radiológico más frecuente en todos los picos fue la opacidad en vidrio esmerilado (28,98%), seguida de la consolidación, que fue la más alta (14,6%) en el pico tres. El recuento de linfocitos disminuyó en todos los picos. Su mayor reducción (16,12) se produjo en el tercer pico. La SpO2 estuvo por debajo del rango normal en todos los picos, excepto en el segundo (90,77%) y quinto (91,06%) picos. La disnea (52,36%) fue el síntoma más frecuente y el mareo (1,26%) y el dolor de garganta (0,6%) los síntomas menos frecuentes. Las tasas de mortalidad fueron 14,4%, 18,2%, 23%, 9,02% y 9,4% en los picos primero a quinto, respectivamente. Conclusión: Como en cada oleada predominaban diferentes variantes del virus SARS-CoV-2, los pacientes con COVID-19 tenían características diferentes en varios picos. La quinta ola de COVID-19 tuvo el mayor número de pacientes hospitalizados, mientras que el primer pico tuvo el número más bajo. Quizás, el aumento significativo en la capacidad de prueba en la quinta ola y su largo período de tiempo sean las razones de este crecimiento. La mayoría de los síntomas clínicos fueron similares en todos los picos, pero la incidencia fue diferente. Dado que los pacientes hospitalizados en el tercer pico tenían la tasa más alta de enfermedad subyacente, puede ser una de las razones del aumento de la tasa de mortalidad de los pacientes. No observamos diferencias significativas en las pruebas de laboratorio entre los pacientes durante los diferentes picos. Por tanto, debemos estar atentos al estudio continuo de las características de la enfermedad, y ser capaces de modificar los tratamientos rápidamente si es necesario.

Molecular typing and antibiotic resistance patterns among clinical isolates of Acinetobacter baumannii recovered from burn patients in Tehran, Iran.

Acinetobacter baumannii (A. baumannii) is now considered a highly resistant pathogen to various types of antibiotics. Therefore, tracking the source of its prevalence and continuous control is crucial. This study aimed to determine antibiotic resistance and perform various molecular typing methods on clinical isolates of A. baumannii isolated from hospitalized burn patients in Shahid Motahari Burn Hospital, Tehran, Iran. Hospital isolates were confirmed by phenotypic and molecular methods. Then the sensitivity to different antibiotics was determined using the minimum inhibitory concentration (MIC) method. In order to perform molecular typing, three-locus dual assay multiplex polymerase chain reaction (PCR), multiple-locus variable-number tandem repeat analysis (MLVA), and multilocus sequence typing (MLST) methods were used. Among the 60 isolates collected, the frequencies of multidrug-resistant (MDR) and extensively drug-resistant (XDR) isolates were 90 and 10%, respectively. The most effective antibiotics were colistin with 100% and tigecycline with 83.33% sensitivity. Isolates were 100% resistant to piperacillin/tazobactam and cephalosporins, and 68.3% were resistant to carbapenem. The results of multiplex PCR showed five groups that international clone I (IC I) and IC II were the most common. The MLVA method identified 34 MLVA types (MTs), 5 clusters, and 25 singletons. Multilocus sequence typing results for tigecycline-resistant isolates showed seven different sequence types (STs). Increasing antibiotic resistance in A. baumannii isolates requires careful management to control and prevent the occurrence of the pre-antibiotic era. The results of this study confirm that the population structure of A. baumannii isolates has a high diversity. More extensive studies are needed in Iran to better understand the epidemiology of A. baumannii.

Linezolid resistance in multidrug-resistant mycobacterium tuberculosis: A systematic review and meta-analysis.

Introduction: Linezolid (LNZ) is an effective antibiotic to treat patients with multidrug-resistant tuberculosis (MDR-TB) treatment failure. M. tuberculosis strains resistant to isoniazid and rifampin are defined as MDR-TB. In recent years, resistance to LNZ among MDR-TB cases has been reported in several different countries. In this study, we performed a systematic review and meta-analysis to investigate the prevalence of LNZ resistance among MDR-TB isolates. Methods: The databases of Embase, PubMed/Medline, and Web of Science were searched systematically from January 2000 to April 2021. Statistical analyses were performed by using Comprehensive Meta-Analysis software. Heterogeneity was reported by using the t-squared statistic and Q-statistic. Begg's rank correlation in combination with the funnel plot were used to evaluate any possible publication bias. Results: In total, 25 studies were selected for meta-analysis from 14 different countries; the majority was from China (n = 5) and Turkey (n = 4). Moreover, 7,366 patients were infected with MDR M. tuberculosis. Among the study population, 98 patients were co-infected with HIV, and 18 patients with hepatitis C virus (HCV). Furthermore, 28 cases had diabetes, and139 cases were alcohol abuser. Overall, 4,956 MDR M. tuberculosis strains were isolated from TB patients. The pooled frequency of LNZ resistance among the clinical isolates of MDR M. tuberculosis was 4.2% (95%). Begg's (p = 0.72) test showed no evidence of publication bias. Conclusion: LNZ resistance among MDR M. tuberculosis isolates is increasing. On the other hand, long-term treatment of MDR-TB cases with LNZ alone is associated with several adverse effects. Thus, it is recommended that newer anti-TB drugs, including bedaquiline and delamanid, in combination with linezolid could increase its effectiveness and decrease toxicities. However, more studies should be done in this field.

Viral vector and nucleic acid vaccines against COVID-19: A narrative review.

After about 2 years since the first detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Wuhan, China, in December 2019 that resulted in a worldwide pandemic, 6.2 million deaths have been recorded. As a result, there is an urgent need for the development of a safe and effective vaccine for coronavirus disease 2019 (COVID-19). Endeavors for the production of effective vaccines inexhaustibly are continuing. At present according to the World Health Organization (WHO) COVID-19 vaccine tracker and landscape, 153 vaccine candidates are developing in the clinical phase all over the world. Some new and exciting platforms are nucleic acid-based vaccines such as Pfizer Biontech and Moderna vaccines consisting of a messenger RNA (mRNA) encoding a viral spike protein in host cells. Another novel vaccine platform is viral vector vaccine candidates that could be replicating or nonreplicating. These types of vaccines that have a harmless viral vector like adenovirus contain a genome encoding the spike protein of SARS-CoV-2, which induces significant immune responses. This technology of vaccine manufacturing has previously been used in many human clinical trials conducted for adenoviral vector-based vaccines against different infectious agents, including Ebola virus, Zika virus, HIV, and malaria. In this paper, we have a review of nucleic acid-based vaccines that are passing their phase 3 and 4 clinical trials and discuss their efficiency and adverse effects.

Evaluation of immune responses to Brucella vaccines in mouse models: A systematic review.

Introduction: Despite the accessibility of several live attenuated vaccines for animals, currently, there is no licensed vaccine for brucellosis in human populations. Available and confirmed animal vaccines may be harmful and considered inappropriate for humans. Thus, human vaccines for brucellosis are required. We aimed to evaluate the effects of Brucella vaccines on mouse models and discuss the potential mechanisms of these vaccines for the design of the appropriate human vaccines. Materials and methods: A systematic search was carried out in Web of Science, Embase, and PubMed/Medline databases. The following MeSH terms were applied: brucellosis, vaccine, Brucella, and vaccination. The original manuscripts describing the Brucella vaccines on mouse models were included. The review articles, editorials, correspondences, case reports, case series, duplicate publications, and articles with insufficient data were excluded. Results: Of the 163 full texts that were screened, 17 articles reached to inclusion criteria. Combining the results of these trials revealed a reduction in bacterial load and colonization rate of Brucella in the spleen, an increase in inflammatory markers, especially IFN-γ and IL-4, and the highest levels of antibody classes in vaccinated animals compared to animals challenged with various virulent strains of Brucella. The majority of studies found that different anti-Brucella vaccines induced a significant protective effect in animals challenged with Brucella strains. Additionally, mice were given the highest level of Brucella vaccine protection and significant clearance of Brucella strains when the immunization was delivered via the IP (intraperitoneal) or IP-IN (intranasal) routes. Conclusion: Brucella is responsible for half-million new cases globally annually, and the lack of a proper human vaccine poses the risk of brucellosis. A variety of vaccines are used to prevent brucellosis. Subunit vaccines and recombinant human vaccines have higher safety and protective properties. Although vaccination helps brucellosis control, it does not eradicate the disease. Thus, we recommend the following strategies. (a) establishment of a registration system; (b) close monitoring of slaughterhouses, markets, and herds; (c) training veterinarians; (d) legal protection of the consequences of non-compliance with preventive measures.

A Comprehensive Review of the Protein Subunit Vaccines Against COVID-19.

Two years after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), in December 2019, the first infections were identified in Wuhan city of China. SARS-CoV-2 infection caused a global pandemic and accordingly, 5.41 million deaths worldwide. Hence, developing a safe and efficient vaccine for coronavirus disease 2019 (COVID-19) seems to be an urgent need. Attempts to produce efficient vaccines inexhaustibly are ongoing. At present time, according to the COVID-19 vaccine tracker and landscape provided by World Health Organization (WHO), there are 161 vaccine candidates in different clinical phases all over the world. In between, protein subunit vaccines are types of vaccines that contain a viral protein like spike protein or its segment as the antigen assumed to elicit humoral and cellular immunity and good protective effects. Previously, this technology of vaccine manufacturing was used in a recombinant influenza vaccine (RIV4). In the present work, we review protein subunit vaccines passing their phase 3 and 4 clinical trials, population participated in these trials, vaccines manufactures, vaccines efficiency and their side effects, and other features of these vaccines.