Archives of Clinical Infectious Diseases
Volume:16 Issue: 4, Aug 2021

Retapamulin is one of the antibiotics recently developed semi-synthetically to inhibit protein synthesis in a specific manner different from other antibiotics. This pleuromutilin derivative shows magnificent anti-bacterial activity in Gram-positive pathogens, especially Staphylococcus aureus and Streptococcus pyogenes, and now it is available in ointment formulations (1%) for clinical use with negligible side effects. Despite the low potential for resistance development, antimicrobial susceptibility rates are significantly high. This is especially important when the prevalence of mupirocin-resistant strains is increasing, and the need for new alternatives is urgent. Unfortunately, due to its oxidation by cytochrome p450, this drug cannot be used systemically. However, another pleuromutilin derivative with systemic use, lefamulin, was approved in August 2019 by the US Food and Drug Administration. In addition to pharmacokinetic features, financial issues are also barriers to consider in the progress of new antimicrobials. In this review, we attempt to take a brief look at the derivatives usable in humans and explore their structures, action mode, metabolism, possible ways of resistance, resistance rates, and their clinical use to explain and highlight the valuable points of these antibiotics.

Recently, epidemiological studies on hepatitis A virus (HAV) infection showed the seroprevalence has been changing due to changes in lifestyle. To the best of our knowledge, there have been no published data on the seropositivity of HAV in Zahedan, southeastern Iran.

This study aimed to investigate the seroprevalence of HAV immunoglobulin G (IgG) antibody in Zahedan, southeastern Iran, to provide the required information for better planning in preventive strategies.

In this cross-sectional study, using the available sampling method, a total of 250 serum samples (18 years and above) in both the urban and rural areas of Zahedan were evaluated for anti-HAV IgG by enzyme-linked immunosorbent assay.

Based on the results, it was observed that 228 out of 250 (91.2%) serum samples were positive for HAV IgG antibody. Male gender, family size, parents’ education, mother’s occupation, and history of jaundice before the age of 12 years were associated with positive HAV antibody (P < 0.001). The seroprevalence HAV rates were not statistically different between the residents of urban and rural regions.

The seropositivity of HAV is high in both the urban and rural areas of Zahedan, Iran. Therefore, the HAV vaccination of the general population is not necessary. It is recommended to monitor HAV seroprevalence in the general population to determine high-risk groups, including anti-HAV seronegative individuals, for HAV vaccination in the residents of the southeast border.

Strongyloides stercoralis is an intestinal nematode with worldwide distribution which is endemic in tropical and subtropical areas. It is unique in its ability to complete its entire life cycle and reinfect its human host via a phenomenon called autoinfection. The majority of infections are clinically asymptomatic or can manifest with gastrointestinal symptoms, such as heartburn, bloating, diarrhea, abdominal discomfort, gastroesophageal reflux disease (GERD), or symptoms related to the penetration of larvae through skin, including dermatitis and eosinophilia. Immunosuppressed patients, such as solid organ transplant patients with untreated strongyloidiasis are at great risk of hyperinfection, dissemination syndromes, and often fatal conditions associated with strongyloidiasis.

In this retrospective single-center cross-sectional study, we evaluated 157 cases (131 heart, lung, and kidney transplant recipients and 26 kidney donors) in Tehran, Iran, from March 2020 to April 2021. Demographic information including age, gender, place of birth, place of residence, underlying disease, being the donor or recipient, history of previous transplant and type of transplant, travel history to endemic regions, and seropositivity for S. stercoralis were evaluated.

Among 157 cases with a mean age of 38.9 years, 40 (25.5%) cases tested positive for S. stercoralis antibodies. Out of 26 donors, eight cases were seropositive, and among 131 recipients, 32 cases were seropositive. There was no significant correlation between birth place and place of residence in endemic areas and seropositivity for S. stercoralis. None of the cases showed hypereosinophilia, hyperinfection, or disseminated syndrome. Also, we found no significant correlation between the type and time of transplant, history of previous transplants, and S. stercoralis infection.

Universal screening for S. stercoralis latent infection is important in immunosuppressed patients, especially in solid organ transplants because of the high risk of hyperinfection and disseminated syndrome, which may culminate in death. Furthermore, screening for latent strongyloides infection in donors seems to be necessary because of the possibility of strongyloides infection being transmitted from donors to recipients.

As an inflammatory process that involves the paranasal sinuses, chronic sinusitis (CS) is one of the most prevalent chronic illnesses that affects all age groups. Parasitic fungi are involved in sinusitis infections.

This study is aimed at the molecular detection of sinusitis caused by such fungi.

Seventy-two samples were collected from the secretions of maxillary and frontal sinuses of patients from Rasoul-e Akram (PbUH) Hospital in Tehran during sinus operation. Fungal genomic DNA was extracted by a DNP kit. The detection of fungi was carried out by employing a sequence-specific target, namely mt cyte b gene locus, and using primers. Polymerase chain reaction (PCR) was optimized, and the limit of detection (LOD) and specificity tests were performed. The amplicon was cloned by the T/A cloning method, which was used for sequencing and positive control.

The 430-bp PCR product underwent appropriate propagation before being amplified and was observed on 1.5% electrophoreses gel. The evaluation of the selected primers with seven DNA constructs from another microorganisms demonstrated 100% specificity. The limit of detection of the optimized test was evaluated up to 50 fungi. Out of 72 samples, 9.7% were positive for fungi existence.

This study indicated that molecular diagnosis of the target mt cyte b gene using LOD enhances clinical laboratory detection of fungal sinusitis.

The emerging problem of antibiotic resistance inPseudomonas aeruginosa is a global health concern; hence, revealing innovative therapeutic approaches (such as designing an immunogenic vaccine candidate) is needed. There is no evidence of the availability of an effective vaccine that can combat the infection caused by this microorganism.

This research was conducted to develop a potential chimeric vaccine against P. aeruginosa using reverse vaccinology approaches.

The present vaccine candidate comprised outer membrane protein F and I (OprF/OprI) and PopB with appropriate linkers. After applying meticulous immune-informatics investigation, the multi-epitope vaccine was created, including helper T lymphocyte (HTL), cytotoxic T lymphocyte (CTL), interferon gamma (IFN-γ), and interleukin 4 (IL-4) epitopes. Then, the physicochemical characteristics, allergenicity, toxicity, and antigenicity were analyzed. After investigating the secondary structure, the tertiary structure (3D) model was generated, refined, and validated via computational methods. Besides, the strong protein-ligand interaction and stability between the vaccine candidate and toll-like receptor 4 (TLR4) were determined via molecular docking and dynamics analyses. Moreover, in silico cloning accompanied by pET-22b (+) was used to achieve high translation efficiency.

Our results presumed that the chimeric-designed vaccine was thermostable and contained optimal physicochemical properties. This vaccine candidate was nontoxic and highly soluble and had stable protein and TLR4 interaction, adequately overexpressed in Escherichia coli. Overall, it could induce immune responses and repress this microorganism.

Therefore, to inhibit Pseudomonas infections experimentally, the efficacy and safety of the vaccine design need to be validated.

Candida albicans is the predominant yeast reported from human infection. Non-albicans Candida species have been recently developed as medically vital fungi. Therefore, it is essential to detect and identify the pathogens at the species level to prescribe appropriate treatment.

This study assessed two complementary methods, including real-time polymerase chain reaction-high resolution melt (PCR-HRM) and polymerase chain reaction-restriction fragment length morphism (PCR-RFLP) with standard PCR and Sanger sequencing as the benchmark.

In total, 66 samples were tested, and two newly-advanced assays were more effective and displayed comprehensive concordance (66/66, 100%) with Sanger sequencing outcomes. Moreover, accurate and economical tests were positively advanced by real-time PCR-HRM for C. albicans and C. parapsilosis complexes.

Given the number of studies performed on the comparison of sensitivity and specificity of phenotypic and genotypic methods to diagnose and identify invasive fungal pathogens and the findings of this study, it could be stated that the correlative PCR-HRM and PCR-RFLP methods were effectively advanced as substitutes for conventional Sanger sequencing for the reasonable identification. However, supplementary evaluations and confirming studies should be carried out with a broad range of samples to standardize this method for routine application in medical laboratories.

The coronavirus disease 2019 (COVID-19) pandemic imposed the most devastating challenge on healthcare systems worldwide. Iran was among the first countries that had to confront serious shortages in reverse-transcriptase-polymerase chain reaction (RT-PCR) testing for severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) and ventilators availabilities throughout the COVID-19 outbreak.

This study aimed to investigate the clinical course of hospitalized COVID-19 patients with different real-time RT-PCR test results during the first three weeks of the outbreak in Qazvin province, Iran.

In this retrospective cohort study, patients with a positive chest computed tomography (CT) scan for COVID-19 who were admitted to all 12 hospitals across Qazvin province, Iran, between February 20 and March 11, 2020, were included and followed up until March 27, 2020. A multivariate logistic regression model was applied to compare the independent associates of death among COVID-19 patients. Then, patients were categorized into six groups based on admission to the intensive care unit (ICU) and rRT-PCR test status (positive, negative, or no test). Also, multilevel logistic regression was used to compare the odds of surviving in each group against the reference group (PCR negative patients not-received ICU) to show if the rational allocation of ICU occurred while its capacity is limited.

In this study, we included 998 patients (57% male; median age: 54 years) with positive chest CT scan changes. Among them, 558 patients were examined with rRT-PCR test and 73.8% tested positive. Case fatality rate (CFR) was 20.68 and 7.53% among hospitalized patients with positive and negative tests, respectively. While only 5.2% of patients were admitted to the ICU, CFR outside ICU was 17.70 and 4.65% in patients with positive and negative results not admitted to the ICU, respectively.

Total CFR in all hospitalized COVID-19 patients in Qazvin province during the first three weeks of the pandemic was 11.7%. Also, according to the results, the main risk factors included a positive rRT-PCR test, age more than 70 years, and having two or more comorbidities or just immunodeficiency disorders. Hence, the ICU admission criteria or prioritized ICU beds allocation should be considered with more emphasis on rRT-PCR results when the capacity of ICU beds is low.

A newly appeared challenge for the healthcare system is the variety of clinical symptoms of COVID-19. In this research, we report 2 cases admitted to Modarres Hospital with unusual postoperative anastomotic failure.

In a 72-year-oldman with a perforated peptic ulcer in D2 and signs of leakage after the first operation and during the second operation due to massive unexpected hemorrhage, we found fully disrupted anastomosis on the second part of the duodenum. Accordingly, the suture ligature of the bleeding ulcer with the closure of the duodenal stump and loop gastrojejunostomy and tube duodenostomy were performed. During the postoperative period, he developed dyspnea, and the diagnostic test of SARSCoV-2 confirmed him as a case of COVID-19. Unfortunately, 1 week after the second surgery, evidence of anastomotic leakage appeared again by bile discharge from drains; although it was managed conservatively, he died because of respiratory failure. In another case, a 65-year-old woman was admitted to the emergency ward with closed-loop small bowel obstruction. After emergency laparotomy, resection of ischemic bowel with primary anastomosis was performed. The same as the previous case, she developed dyspnea, and the diagnostic test resulted positive for COVID-19. After 2 weeks, she was admitted to the hospital with signs of anastomotic leakage that was subsequently confirmed by abdominal computed tomography (CT); although it was managed conservatively, she died because of respiratory failure due to COVID-19.

These cases were unique in that intestinal microangiopathies can cause very severe problems, weaken the body, and eventually death, as we have seen in these 2 cases.

Acquired immune deficiency syndrome (AIDS) inflicts severe damage to the immune system. It is transmitted from one person to another through blood transfusion and vertical and sexual transmission. It should be noted that almost all papers reporting AIDS emphasized that HIV led to immune deficiency. However, this study reported the first HIV-1 seropositive woman who had an active viral load of HIV-1 without any signs or CD4 lymphocyte count depletion.

This study reported a 46-year-old HIV-1 seropositive woman without any signs and symptoms diagnosed 31 years ago by laboratory tests. Also, it is noteworthy that the patient had not received regular therapeutics during the infection period. Our serologic tests showed an active seropositive patient without any CD4 depletion. The viral load of HIV-1 was 132967.2 u/L, which was quantified by a real-time PCR assay. Also, a CBC test was performed and showed no abnormal results.

An untreated HIV-1 positive patient without immunodeficiency is a rare condition, and we found no report of it in the literature. This article reported an HIV-1 positive patient in whom the infection was confirmed several times using the real-time PCR method.

COVID-19 infection causes a wide spectrum of macrovascular thrombosis, which has contributed significantly tomorbidity and mortality in the elderly. Guidelines have recommended extended prophylaxis following discharge from the hospital for variable periods. The risk of thrombosis and the optimal duration of extended anticoagulation remain uncertain.

This study aimed at determining the overall incidence and timing of macrovascular thrombosis in post-COVID-19 elderly patients. It also aimed at finding out the predictive value of clinical severity, in-hospital anticoagulation, and discharge Ddimer values for the incidence of macrovascular thrombosis and overall mortality within 13 weeks following clinical recovery from acute COVID-19 infection in the elderly.

In this study, 288 elderly patients with symptomatic acute COVID-19 infection discharged between August 1, 2020, and November 30, 2020, were enrolled. Details regarding the incidence of macrovascular thrombosis were collected through a telephone interview after 90 days. Data were tabulated and analyzed with IBM SPSS Statistics for Windows, Version 23.0. (Armonk, NY: IBM Corp.)

The number of macrovascular thrombotic events was significantly higher in group C (critical illness) than in the other two groups (17.9 vs. 1.8 and 1.1%, respectively) (P = 0.0005). Three (10.7%) patients died within 13 weeks of discharge in group C, versus one (0.6%) patient in group M (mild to moderate illness) and none in group S (severe illness) (P = 0.0005). There were two macrovascular thrombotic events in the elevated D-dimer group versus one in the reduced D-dimer group (P = 0.135). The number of deaths was high in the elevated D-dimer group [2 (8.3%) vs. 0 (0), P = 0.053]. The cumulative incidence rate of macrovascular events in the post-COVID-19 elderly cohort 13 weeks after discharge was 3.12%.

Elderly patients with a critical illness during hospitalization due to COVID-19 and elevated D-dimer values at discharge have the maximum risk of developing macrovascular thrombosis in the post-COVID-19 period. It is reasonable to recommend extended thromboprophylaxis for at least eight weeks in the post-COVID-19 elderly