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Background: In this study, attempts were made to evaluate the frequency of high-level gentamicin-resistant (HLGR) and vancomycin-resistant enterococci (VRE) and the prevalence and antibiotic resistance profile of enterococcal species isolated from pediatric patients referred to Children's Medical Center Hospital, Tehran, over five years., Materials and Methods: A total of 404 enterococcal isolates from different patients referred to the Children's Medical Center between March 2016 and March 2021 were included in this cross-sectional study. Antimicrobial susceptibility testing was performed using standard methods according to the guidelines of the Clinical Laboratories Standards Institute (CLSI)., Results: Approximately one-third of the enterococcal strains were isolated from urology and intensive care units. 17.3% of the isolates were obtained from outpatient sources. However, 82.7% of the isolates were sourced from inpatient settings. We found that the rates of resistance to ampicillin, penicillin, and vancomycin were twice as high in inpatients as in outpatients. Of the total isolates, 87.4% and 49.3% were identified as HLGR and VRE, respectively. In addition, we identified 2% of the VRE isolates that were not susceptible to linezolid. Nitrofurantoin showed excellent activity against enterococcal isolates in the urine, with a susceptibility rate of 92.5%., Conclusion: The present study reports the highest range of VRE isolated from pediatric patients in Iran. Despite the predominance of HLGR enterococci in our region, vancomycin remains effective against such strains. This study is among the few to demonstrate the incidence of linezolid-insensitive VRE in pediatric patients. Therefore, it is important to evaluate effective infection control measures to prevent linezolid and vancomycin resistance in enterococci., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2024 Bahram Nikmanesh et al.)

Here, we described the efficacy of colistin sub-minimum inhibitory concentrations (sub-MICs) on biofilm-forming activity, host epithelial cell adherence, and invasion capacity of Acinetobacter baumannii strains collected from children admitted to the Children's Medical Center Hospital. Biofilm formation potency of A. baumannii clinical isolates was measured using a 96-well microtiter plate assay. Distribution of biofilm-related genes, including bap , abaI , ompA , csuE , and bla PER-1 , was detected by PCR. The mRNA expression level of ompA and csuE was measured by qPCR in the presence of ¼ and ½ MICs of colistin. A. baumannii adhesion and invasion to eukaryotic host cells were phenotypically assayed at sub-MICs of colistin. Eighty percent (56/70) and 35.7% (25/70) of A. baumannii isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR) phenotypes, respectively. The strong, moderate, and weak biofilm producers of A. baumannii were 37.1% (26/70), 32.8%, (23/70), and 22.8% (16/70), respectively. The frequencies of biofilm-associated genes were 100% for abaI , ompA , and csuE , followed by 22.8% (16/70) and 24.3% (17/70) for bap and bla PER-1 , respectively. The downregulation of csuE and ompA expression levels was observed in the sub-MIC of colistin. In vitro cell culture study showed a decreased capability of A. baumannii to adhere to the human epithelial cells at sub-inhibitory doses of colistin; however, none of the isolates could invade HEp-2 cells. Our study showed that the genes encoding biofilm-associated proteins undergo downregulation in expression levels after exposure to sub-MICs of colistin in A. baumannii . Longitudinal in vivo studies are needed to fully understand the clinical aspects of pathogenicity mechanisms and evolutionary dynamics of drug resistance.IMPORTANCESince the toxicity of colistin is dose dependent, there is a focus on strategies that reduce the dose while maintaining the therapeutic effect of the drug. Our findings about sub-inhibitory doses of colistin provide a novel insight into the logical use of colistin to treat and control Acinetobacter baumannii -related infections in clinical practice., Competing Interests: The authors declare no conflict of interest.

This systematic review provides a comprehensive overview of natural SARS-CoV-2 infections in companion animals. The findings show that these infections are relatively rare. Among the examined dogs, only 1.32% tested positive for SARS-CoV-2, while for cats, the rate was 1.55%. Infections in rabbits and ferrets were even less common, at less than 1%. These results support previous research indicating the infrequency of natural infections in companion animals. The review also includes updated studies that involved various pets, such as cats, dogs, ferrets, and rabbits. The majority of the studies analyzed were primarily concerned with screening pets that visited veterinary clinics, regardless of whether they showed any specific signs of SARS-CoV-2 infection. Only a limited number of studies investigated infections in animals suspected of being in contact with owners or other animals that had COVID-19 or were exhibiting symptoms. The most common variant identified among the SARS-CoV-2 variants in the reviewed studies was B.1.1.7 (alpha), followed by B.1.617.2 (delta), B.1.526 (Iota), and others. The emergence of these variants raises concerns about their potential for increased transmissibility and virulence, highlighting the importance of ongoing monitoring of SARS-CoV-2 infections in both humans and animals. Furthermore, most of the reviewed studies indicated that infected pets either showed no symptoms or experienced mild symptoms. This aligns with previous reports suggesting that animals infected with SARS-CoV-2 generally have less severe illness compared to humans. However, it is essential to recognize the possibility of severe illness or death in animals, particularly those with underlying health conditions. Continuous surveillance of SARS-CoV-2 infections in companion animals is crucial for better understanding the virus's epidemiology in animals and developing effective strategies to protect both animal and human health., (© 2024 John Wiley & Sons Ltd.)

Candidemia caused by rare and uncommon Candida species is becoming more prevalent in pediatric healthcare settings, resulting in significant morbidity and mortality. One such species, Candida palmioleophila , is resistant to fluconazole but highly susceptible to echinocandins. Here, we report the first documented case of C. palmioleophila candidemia in Iran that occurred in a male infant with biliary atresia who had been hospitalized for 2 months. The patient's blood and urine cultures were positive for both yeast and bacterial species. Through DNA sequence analysis, the yeast isolate was identified as C. palmioleophila . In vitro antifungal susceptibility testing of the isolate against amphotericin B, fluconazole, itraconazole, voriconazole, isavuconazole, posaconazole, and nystatin revealed MIC values of 2, 16, 0.25, 0.0625, 0.125, 0.25, and 4 μg/mL, respectively, and minimum effective concentration for caspofungin was 0.031 μg/mL. Despite receiving antibacterial and antifungal therapies, the patient unfortunately expired due to bradycardia and hypoxemia. Proper identification and epidemiological surveillance studies are needed to understand the exact prevalence of these emerging yeast pathogens. Previously reported cases of C. palmioleophila infection, primarily associated with bloodstream infections and catheter-related candidemia, were reviewed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Aboutalebian, Nikmanesh, Mohammadpour, Charsizadeh and Mirhendi.)

The incidence of invasive candidiasis in pediatric patients is increasing and is associated with significant morbidity and mortality. C. pelliculosa has been rarely reported as a human pathogen, however, it has been associated with serious nosocomial infections and clonal outbreaks with poor clinical outcomes in immunocompromised children were reported. Here, we describe the first case of candidemia due to Candida pelliculosa in a 5-year-old immunocompromised male suffered from Griscelli syndrome with hemophagocytic syndrome hospitalized in the pediatric intensive care unit (PICU), Tehran, Iran. In addition, the history of reported cases or case-series due to C. pelliculosa is reviewed., Competing Interests: Conflicts of Interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022. Published by Elsevier Masson SAS.)

Acute appendicitis represents one of the most common causes of emergency abdominal surgery worldwide. Meanwhile, Enterobius vermicularis has been suggested as one of the probable causes of appendicitis. In this study, the morphological characteristics of the remnant pinworms and pathologic changes were explored in old-archived FFPE tissues of appendectomies. Moreover, we provide the first molecular identification, genetic, and haplotype variation of this nematode from the old-archived FFPE tissue section of appendectomy using the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Seventeen FFPE appendectomies with E. vermicularis infection, stored over 12-22 years, were collected from two different geographical areas of Iran. In the histopathological examination, tissue changes were observed in thirteen cases (76.4%) and inflammation in four blocks (23.5%). After DNA extraction, the cox1 gene was amplified in twelve (70.6%) cases using the nested polymerase chain reaction (PCR). Phylogenetic analysis and a median-joining network of 78 available cox1 sequences of E. vermicularis revealed 59 haplotypes. We identified five haplotypes that fell into type B. All Haplotypes are novel except for two haplotypes, Hap32 and Hap37, identical to E. vermicularis sequences from Iran, Greece, and Germany. The ranges of diversity distance and haplotype diversity within the isolates were 0-1.9% and HD:0.643-0.667, subsequently. Overall, the absence of inflammation or even tissue changes in some sections can suggest the possible non-inflammatory role of E. vermicularis in appendicitis. Although FFPE material suffers from PCR inhibition, we could successfully use nested PCR to characterize E. vermicularis in old-archived appendectomy blocks and suggest this method as a complementary diagnosis technique in pathology. While the predominant type was B in the Middle East and Europe, further studies on a larger sample size from different geographical regions could probably confirm the results obtained in the present study., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Haghshenas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background and Purpose: Given the high mortality rate of invasive candidiasis in hospitalized pediatric patients, it is crucial to establish a predictive system to achieve early diagnosis and treatment of patients who are likely to benefit from early antifungal treatment. This study aimed to assess the Candida colonization index, species distribution, and antifungal susceptibility pattern of Candida strains isolated from pediatric patients with high Candida colonization index (CI)., Materials and Methods: This study was carried out at the Children's Medical Center in Tehran-Iran. In total, 661 samples were collected from 83 patients. The Candida CI was calculated according to the descriptions of previous studies. The isolates were identified using polymerase chain reaction-based techniques. The Clinical and Laboratory Standard Institute protocol M60 was used to conduct the antifungal susceptibility test., Results: A colonization index greater than 0.5 was confirmed in 29 cases (58% of positive samples) with two children developing candidemia. Candida albicans (n=53, 49.5%) was the most common Candida species in patients with CI > 0.5. Except for acute lymphoblastic leukemia, no risk factors were linked to a high index in colonized children ( P > 0.05). Twelve isolates (7.01%) were multi-azole resistant with high MICs against both isavuconazole and ravuconazole and seven strains (4.09%) were echinocandins resistant., Conclusion: In pediatric intensive care units, patients are at risk of fungal infection, particularly candidemia. In this study, more than half of the children with positive yeast cultures had CI > 0.5, and 6.8% developed candidemia., Competing Interests: There is no conflict of interest., (Copyright: © 2021, Published by Mazandaran University of Medical Sciences on behalf of Iranian Society of Medical Mycology and Invasive Fungi Research Center.)

Background and Purpose: This study aimed to evaluate the species distribution and susceptibility pattern of the strains isolated from Candida colonization in pediatric patients staying at pediatric intensive care unit (ICU) and infant ICU of Children's Medical Center in Tehran, Iran., Materials and Methods: This study was conducted in the Children's Medical Center in Tehran, Iran. In total, 440 samples from 56 patients with oral cavity, skin surrounded catheters, and ear, throat, nasal, and urine cultures were collected. All patients were evaluated in terms of Candida colonization on the admission day as well as the days 7, 14, and 28 according to the previous studies. CHROMagar Candida medium was applied for primary/multiple species identification and the isolates were identified by using polymerase chain reaction-based methods to the species-specific complex level. The antifungal susceptibility test was performed according to the Clinical and Laboratory Standards protocol published as M27-A3 and M60 documents., Results: In total, 136 yeast samples from 26 individuals (30.9%) out of 440 samples were considered colonization. The most prevalent species in IICU was C. albicans (27%, n=20) followed by C. krusei (24 %, n=18) and C. parapsilosis (16%, n=12). In PICU, the predominant species was C. krusei (40%, n=24) followed by C. parapsilosis (18%, n=11) and C. dubliniensis (16%, n=10). Among the 40 tested isolates from both units, fluconazole-resistant isolates (n=11, 8.15%) were determined according to the new breakpoints. In the case of echinocandins, 2 isolates, including C. albicans (n=1) and C. krusei (n=1) were resistant against both caspofungin and anidulafungin (totally 1.48%)., Conclusion: In the present study, since C. krusei is intrinsically-resistance against fluconazole, emphasizing the importance of species-level identification of Candida isolates is outstanding. However, according to the antifungal susceptibility testing results, only 7.2% of the strains were resistant to fluconazole. It would be beneficial to monitor the ICU patients who are at high risk of invasive Candida infection., Competing Interests: There is no conflict of interest., (Copyright: © 2021, Published by Mazandaran University of Medical Sciences on behalf of Iranian Society of Medical Mycology and Invasive Fungi Research Center.)

Background: Multiple yeast species can cause human disease, involving superficial to deep-seated infections. Treatment of these infections depends on the accurate identification of causative agents; however, reliable methods are not available in many laboratories, especially not in resource-limited settings. Here, a new multiplex assay for rapid and low-cost identification of pathogenic yeasts is described., Methods: A two-step multiplex assay named YEAST PLEX that comprises of four tubes and identifies 17 clinically important common to rare yeasts was designed and evaluated. The set also provides PCR amplicon of unidentified species for direct sequencing. The specificity of YEAST PLEX was tested using 28 reference strains belonging to 17 species and 101 DNA samples of clinically important non-target bacteria, parasites, and fungi as well as human genomic DNA. The method was further analyzed using 203 previously identified and 89 unknown clinical yeast isolates. Moreover, the method was tested for its ability to identify mixed yeast colonies by using 18 mixed suspensions of two or three species., Results: YEAST PLEX was able to identify all the target species without any non-specific PCR products. When compared to PCR-sequencing/MALDI-TOF, the results of YEAST PLEX were in 100% agreement. Regarding the 89 unknown clinical isolates, random isolates were selected and subjected to PCR-sequencing. The results of sequencing were in agreement with those of YEAST PLEX. Furthermore, this method was able to correctly identify all yeasts in mixed suspensions., Conclusion: YEAST PLEX is an accurate, low-cost, and rapid method for identification of yeasts, with applicability, especially in developing countries., (© 2022 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Candida meningitis is a rare life-threatening yeast infection mostly involving immunocompromised or paediatric patients undergoing neurosurgical procedures or shunt placement. Due to difficulties in diagnosis because of diverse clinical manifestations, the number of patients affected is most likely underestimated. Therefore, the correct diagnosis may be delayed for months, and accurate species identification is highly recommended for administering appropriate antifungal therapy. We report the first case of fluconazole-resistant Candida auris meningitis in a paediatric patient in Iran. This strain was probably imported, as it genotypically belonged to Clade I from South Asia. Furthermore, we include a literature review of C auris meningitis cases, as the number of cases with C auris meningitis has increased with reports from the United Kingdom, India and Iran. This problem might increase further in the era of COVID-19 due to attrition of experienced healthcare personnel and a high workload of hospital healthcare workers. To understand the precise prevalence of this emerging multidrug resistance pathogen, epidemiological surveillance studies are urgently warranted., (© 2021 Wiley-VCH GmbH.)

Transmission of Pseudomonas aeruginosa along the food chain could cause gastrointestinal infections. To show this involvement, the prevalence, putative virulence genotype, and antibiotic resistance phenotype of P. aeruginosa isolates from stool of 1482 patients with community and hospital acquired diarrhea were compared with 87 isolates from the environmental samples. The results showed infection with P. aeruginosa in 3.4% of the cases, while 57.4% of vegetable samples were contaminated. Significantly higher frequency of lasB (98%), aprA (98%), exoY (98%), and exoS (90%), but lower rate of exoT (39.2%), was detected among the stool isolates. Multi-drug resistance (MDR) phenotype was detected in 25.5% and 4% of the stool and vegetable isolates, respectively. A higher rate of studied virulence genes was detected among the MDR strains vs non-MDR strains. These results indicate P. aeruginosa as a causative agent of diarrhea either among the hospitalized patients and those with community-acquired diarrhea.