ISSN / EISSN : 2280-6423 / 2280-6423
Published by: PAGEPress Publications (10.4081)
Total articles ≅ 1,897
Latest articles in this journal
Microbiologia Medica, Volume 36; https://doi.org/10.4081/mm.2021.9335
Background and aims. Scedosporium species and Lomentospora prolificans are the filamentous fungi isolated more frequently from the cystic fibrosis (CF) lower airways, after Aspergillus fumigatus. Previous studies showed that, in CF patients, Scedosporium species and Lomentospora prolificans are responsible for airways colonization/ infection, enhancing pulmonary deterioration, and for severe invasive infections in CF patients undergoing lung transplantation. Aims of our project were to evaluate the prevalence of Scedosporium and Lomentospora species in Italian patients with CF, and to evaluate the interest of the Scedosporium-selective colture medium SceSel compared to routinely used agar-based culture media, in order to improve laboratory diagnostic performances.Materials and methods. A total of 1977 sputum samples from 1154 CF patients were collected and processed according to CF Italian recommendations in the year 2017 (January 1st to December 31st). The SceSel agar was used in addition to the routine culture procedures to burst growth and isolation of Scedosporium/ Lomentospora species. The fungal isolates were identified by classical mycological methods and polymerase chain reaction-based DNA sequencing of ITS1 and ITS4 regions. Susceptibility of the isolates to antifungal drugs was investigated by E-test method. Results. Among the 1154 enrolled patients, 62 (5.3%) were positive for Scedosporium/Lomentospora species (median age: 27y; range 8-64y; 33 male). Out of 1977 samples, 93 were positive for Scedosporium/Lomentospora species, and 13 (13.9%) were recovered only on SceSel agar. According to molecular analyses, isolation rates of each species were: S. apiospermum 53.1%, S. boydii 37.5%, L. prolificans 6.3% and S. aurantiacum 3.1%. Amphotericin B minimum inhibitory concentration (MIC) values were above or equal to 2 mg/L in all strains. Voriconazole MIC values were below or equal to 0.38 mg/L in almost all strains, proving this drug to be the most effective antimycotic for members of Scedosporium species. Otherwise, Lomentospora prolificans showed to be resistant to all considered antifungal drugs, only Voriconazole seems to be active on some Lomentospora prolificans isolates. Conclusions. Our results suggest that SceSel agar should be used in combination with routine media as standard microbiological protocol and procedures are not always adequate to isolate Scedosporium and Lomentospora species in CF respiratory samples. Molecular identification and susceptibility tests are needed, especially for strains isolated from critical patients and those considered for transplantation, as they might develop invasive scedosporiosis.
Microbiologia Medica, Volume 36; https://doi.org/10.4081/mm.2021.9623
Background and aims: Rapid and accurate diagnosis is essential to limit the spread of SARS-CoV-2 and for patient’s management. Currently, real-time reverse transcription polymerase chain reaction (RT-PCR) is the recommended laboratory test to detect SARS-CoV-2. However, the requirement of special instruments and skilled personnel have limited the use of this technique. Recently, several rapid antigen detection tests have been developed and used as frontline. The aim of this work was to assess the performances of STANDARD F COVID-19 Ag FIA Kit, a rapid fluorescence immunoassay for the detection of SARS-CoV-2 nucleoprotein antigens, in comparison to RT-PCR.Materials and methods: Twenty-three nasopharyngeal swabs were collected and tested. Results: Among the 20 positive RT-PCR samples, 9 were detected by the immunofluorescence assay, reporting an overall sensitivity of 45%. The sensitivity increased to 64% in the case of a high viral load, where all three target genes, RdRp, N, and E, were detected by RT-PCR. Conclusions: A better antigen detection rate is associated with low Cycle threshold values which are inversely related to the viral load. STANDARD F COVID-19 Ag test cannot be considered as the frontline assay for COVID-19 diagnosis, but it might be used in association with clinical signs of patients to reduce the number of RT-PCR testing.
Microbiologia Medica, Volume 36; https://doi.org/10.4081/mm.2021.9354
In the European Union between 2008 and 2017 there was a statistically significant decrease in the confirmed cases of salmonellosis. Nevertheless, it represents the first cause of food-borne outbreaks and the secondly most frequently reported zoonosis. Considering the pathogen diffusion and clinical consequences, monitoring the incidence of Salmonella spp. infections is a priority for public health. The study is aimed at describing the temporal trend of prevalence of Salmonella spp. positive tested and serotypes characteristics of the isolates by L’Aquila hospital laboratory microbiological analysis in 2011-2018, with a focus on the epidemic phase occurred from October 2013 to May 2014. The survey is a case series report, with a retrospective design. During the period considered, 220 infected carriers were identified, in particular 160 positive samples for Salmonella enterica serogroup B, so it was the main group causing salmonellosis in the area of L’Aquila both in the epidemic period and in the non-epidemic period. Moreover, the proportion of cases in early paediatric age (from one to five years) resulted statistically higher in the epidemic period than in the non-epidemic period. About the possible causes of the outbreak, the hypothesis of an environmental contamination seems to be plausible.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.9176
Group C Streptococci comprises of Streptococcus dysgalatiae that is further divided into two subspecies, namely S. dysgalactiae subspecies equisimilis and S. dysgalactiae subspecies dysgalactiae. S. dysgalactiae subspecies dysgalactiae is mainly an animal pathogen but few cases of human infections have been described in the literature. A 40 year old patient presented to the hospital with complaints of pain in pelvis and suprapubic area. Urine sample of the patient was subjected to microscopy and culture for isolation and identification of the etiological agent. S. dysgalactiae subspecies dysgalactiae was identified from the clinical specimen of the patient by conventional and automated methods. The patient was successfully treated with third generation cephalosporin. With newer or rarely reported pathogens causing human diseases and increase in number of immunocompromised individuals in the population, the pathogenic potential of such isolates should not be undermined and a careful correlation with the clinical profile should help guide a clinician in optimum treatment of the patient.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.9047
Background: Human non-polio enteroviruses (NPEVs) have been associated with certain life-threatening disorders in children. However, there is paucity of NPEV infection data in most developing countries. This study determined the 3-year prevalence of non-polio enteroviruses (NPEVs) among children in some Northern States of Nigeria. Materials and Methods: Duplicate stool samples were collected from 27778 children ≤15 years. These samples were processed and analyzed for characteristic NPEVs cytopathic effects (CPE) on L20B and RD cell lines. Tests were considered positive if the duplicate samples produced distinct CPE on both cell lines. Results: Of the 27778 samples processed, 3991 (14.4%) NPEVs were isolated. Participants of the male gender (14.5%) within the age range of 0-5 years (14.7%) from Yobe state (15.3%) whose samples were received in the month of June (22.2%) and in the year 2015 (18.8%) had the highest prevalence of NPEVs. June had significant risk factors of NPEVs (p˂0.001, OR=1.95 [95%CI: 1.60-2.34]). However, there was no significant association between age, sex and location of sample collection with the prevalence of NPEV (p˃0.05) Conclusions: This study revealed a relatively high prevalence of NPEVs among the study population. This calls for the need for government implementation of consistently improved water, food and environmental hygiene.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.9375
Many individuals are wearing face masks improperly at ‘half mask’ and potentially breathing out microbes that can contaminate the air as well as anything below the nose. This note provides the first report that bacteria and fungi breathed out during nasal air exhalation are able to be cultured after landing on blood agar plates. The CFU’s are higher after both 10 breaths and extremely significant for 20 breaths compared to the control plates exposed to the air. Implications of this finding are that going ‘nose commando’ may be able to continue the spread of respiratory diseases such as COVID-19. Minute bioaerosols carrying bacteria may be designated as microsnot.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.8965
The infrequency of urinary tract and blood stream infections caused by Aerococcus urinae is most probably due to the difficulties in the identification of this bacterium using standard microbiological methods. With the introduction of more sensitive and accurate techniques in clinical microbiology, such as genetic approaches and Matrix-Assisted Laser Desorption/Ionization-Time Of Flight (MALDI-TOF) mass spectrometry (MS), the incidence of infections due to A. urinae increased. Herein, we described a case of urinary tract and bloodstream infection caused by A. urinae, which occurred in an 86-year-old Caucasian man with a previous history of prostate cancer. The identification of A. urinae was performed by MALDI-TOF MS, since this microorganism cannot be identified by biochemical reactions. In this report, we highlight the need to consider MALDI-TOF MS as technique of choice for A. urinae identification in the presence of subjects with predisposing factors, such as old age, male gender, and genitourinary tract pathologies.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.9191
The following document is based on the current knowledge of SARS-CoV-2 and the related disease (COVID-19). The Italian Institute of Health (ISS) is monitoring the virus spread throughout the country through daily reports sent by individual regions and regional reference laboratories. The diagnosis of infection is based on the use of standardized and validated molecular tests for the search for viral RNA in different sets of biological samples, from patients suspected of having contracted the infection. This document provides a specific guidance for the collection and storage of biological samples from deceased persons. It also provides recommendations on safety practices to be adopted during both collection and handling of specimens, and during autopsy procedures. With regard autopsy, it is recommended to follow the procedures for the execution of diagnostic findings in patients died with SARS-CoV-2 infection issued by ISS Working Group on Causes of Death from COVID-19, published on March 27, 2020.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.9269
Urinary tract infections (UTIs) are among the most common bacterial infectious diseases occurring in the community and healthcare setting. Most community-acquired urinary tract infections are usually treated empirically. The knowledge of antibiotic resistance patterns of the microorganisms causing UTI is essential for defining the empirical treatment. The aim of the present study is to investigate the prevalence and the resistance patterns of bacterial species isolated from lower urinary tract infections, in a large population of Milan area. A retrospective analysis of the isolates obtained from urine samples received at the microbiology laboratory of Centro Diagnostico Italiano of Milan was performed from January 2019 to December 2019. Urine samples were plated on differential medium by automated inoculation system. Identification and antibiotic susceptibility testing were performed using the Phoenix 100™ system. All results were interpreted according to the European Committee on Antimicrobial Susceptibility Testing breakpoints. During a 12-month period a total of the 51,980 urine samples have been processed and 21,4% (11.148) were found to be positive (bacterial count ≥105CFU/mL). Overall Escherichia coli was the most common Gram-negative bacteria of all isolates (72%), followed by Klebsiella pneumoniae (10.8%) and Proteus mirabilis (3.3%). Susceptibility of E. coli to oral antimicrobial agents was demonstrated to be as follows: fosfomycin (97%), trimethoprim/sulfamethoxazole (76%), ciprofloxacin (89%), ampicillin (51%) and amoxicillin/clavulanate (77%). The present study point-out the common antibiotic resistance trend of uropathogens in this area. Our results will help in the formulation of antibiotic policy and determination of empirical treatment of urinary tract infection.
Microbiologia Medica, Volume 35; https://doi.org/10.4081/mm.2020.8709
Bacteriophages are viruses that infect bacteria. Since their discovery in the last century, they have proved their effectiveness in biocontrol of bacteria. In this mini-review, we provide a brief history of bacteriophages, their life cycle and classification. We also discuss the potential use of bacteriophage in clinical therapy as an alternative to antibiotics, comparing their advantages and disadvantages.