ACTA Microbiologica Hellenica (Volume 65, Issue 4)

Evaluation of sample pooling in SARS-CoV-2 testing using the Taq-Path™ COVID-19 Combo Kit

Georgios Meletis 1, Konstantinos Lilakos 2,3, Georgia Gioula 1, Maria Exindari 1, Anna Papa 1

1.Laboratory of Microbiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece.
2.ANTISEL SA, Athens, Greece.
3.Hematology Clinic, University of Athens Medical School, Athens, Greece.

The worldwide spread of SARS-CoV-2 has led to a high demand for COVID-19 molecular testing. However, mass testing is causing heavy laboratory backlogs, reagent shortages and laboratory personnel burnouts. To overcome these difficulties, testing samples in pools has been shown to be an effective strategy for low COVID-19 prevalence regions. In the present study, we evaluated the effectiveness of pooled nasophryngeal specimens testing using the TaqPath COVID-19 Combo Kit. Four confirmed positive samples were tested individualy and also used as positive spike-ins for the pooling protocol. Each one was pooled with four different confirmed negatives to a total of five samples per pool. Five microliters of RNA were used for each reaction, whereas reactions with increased RNA input (10 and 15 ul) were performed to investigate probable effects on sensitivity and assay performance. All samples which were tested either individually or in pools resulted positive. Our results showed that testing in pools of five samples using the TaqPath COVID-19 Combo Kit is a reliable option for SARSCoV- 2 detection, especially when mass testing is urgently needed.

Key words: SARS-CoV-2; COVID-19; pooling; molecular test; Real-time RT-PCR

Microbial indoor air quality and antibiotic resistance profile in the operating theatre of a university hospital (Bechar, Algeria)

Mourad Draoui, Abdelhadi Seghir, Abdellah Moussaoui, Nora Nahal Bouderba

Laboratory of Plant Resource Development and Food Security in Semi-arid Areas, South West of Algeria, BP 417,
University of Tahri Mohamed Bechar, 08000, Bechar, Algeria

The emergence of novel or recurring pathogens and the multi-resistance of certain species towards antibiotics have led us to the surveillance of the microbial prevalence in the hospital’s air. This study has deployed a methodological demonstration of the prominence of nosocomial pathogens in the University Hospital, Bechar (Algeria).
Airborne particles have been collected out of surgery and postoperative halls using the biocollector “M-Air-T”. After identifying the collected species, the antibiotic resistance of bacterial strains was evaluated.
The following pathogens were identified: Staphylococcus spp., with a dominance of 47.7%, in which we have found that 9% belong to the specific species of S. aureus, followed by 18.7% of Enterobacter spp., and noting an abundance of molds and yeast (Aspergillus spp.,including A. niger, Penicillium spp., Cladosporium spp., Alternaria spp., Rhizopus spp. and Mucor spp.)
Antibiotic resistance pattern observed included: for S. aureus to oxacillin, amoxicillin and ampicillin, and for Pseudomonas  aeruginosa, and Bacillus spp. to beta-lactam family antibiotics. Factors influencing the risk of nosocomial infection have been found to vary depending on the type of surgery, age, length of preoperative hospitalization, duration of the operation and the
number of people in the operating room. So, control of nosocomial infections requires, on one hand a proper isolation of the implicated pathogens in order to clearly otuline this problem, and on the other hand awareness pf resistance patterns for each of these pathogens. It is obvious that in addition to compliance with the basic rules of hygiene, the judicious use of drugs, the implementation of a policy of monitoring and a consortium between clinicians, microbiologists, and hospital pharmacists, remain essential to fight these hospital acquired infections.

Key words: Bio-collector, bacterial strains, M-Air-T, hygiene,nosocomial infections

Antimicrobial study and in vitro evaluation of coated contact lenses with polyelectrolyte complex based on Chitosan and Sodium Alginate

Sara Nawel Gasmia,b, Rachida Kirdia,b, Maamar Khamesa,b

a.Laboratory of experimental Biology and Pharmacology, University of Medea, Nouveau pole urbain, Medea
University, 26000 Medea, Algeria
b.Faculty of Sciences, University of Medea, Nouveau pole urbain, Medea University, 26000 Medea, Algeria.

Ametropia correction by contact lenses can improve visual quality. However, their use may be burdensome and uncomfortable, particularly when poor wearer care increases the possibility of microbial contamination. The aim of this work is to coat silicone hydrogel contact lenses with a polyelectrolyte complex based on sodium alginate and chitosan, to study their antimicrobial
power and their physicochemical characteristics. A preliminary study on the antimicrobial activity of the electrolyte complex was carried out. The latter exhibited antimicrobial activity on all strains studied (i.e.: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and the fungus Candida albicans) with inhibition zone diameters ranging
from 11 to 15 mm. The antimicrobial study of coated contact lenses was performed on the same strains and showed a more bacteriostatic than bactericidal effect. To estimate the water retention capacity of these lenses, swelling and erosion tests were performed. Contact lenses coated with the ALG/CTS polyelectrolyte complex showed a maximum swelling rate of 343%
after 360 minutes of contact with artificial tears and an erosion rate of 37% after 48 hours. This study will be followed by an in vivo study to comfort level evaluation of the coated lenses.

Key words:Contact lens, Sodium Alginate, Chitosan,Polyelectrolyte complex, Antibacterial activity

Investigation of the Antileishmanial Activity of Medicago sativa Extract:An in vitro Study

Hamide Ghafoori1, Reyhaneh Sadat Sandoughsaz1, Farzaneh Mirzaei1, Hadi Zare-Zardini2,3,4,
Hossein Soltaninejad5

1.Department of Medical Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical
Sciences, Yazd, Iran
2.Hematology and Oncology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
3.Medical Nanotechnology & Tissue Engineering Research Center, Yazd Reproductive Sciences Institute, Shahid
Sadoughi University of Medical Sciences, Yazd, Iran
4.Department of Sciences, Farhangian University, Isfahan, Iran
5.Department of Nano Biotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran 14115, Iran.

Leishmaniasis is a group of parasitic diseases caused by various species of Leishmania. Cutaneous manifestations of the disease can cause protracted wounds, difficult to heal, thus it is important to discover novel compounds that can augment in wound healing. The aim of this study is to investigate antileishmanial activity of Medicago sativa extract. Parasites were treated
with different concentrations of plant extract (5, 100, 250, 500 and 1000 μg/ml) for 24, 48, and 72 hours. The characterization was done by reversed phase-high performance liquid chro-matography (RP-HPLC). The IC50 values were 566.62, 445.74, and 375.74 after 24, 48, and 72 hours incubation, respectively. The results showed that the survival of this parasite can be limited
by increasing the incubation time and/or the extraction dosage. The analysis of extract showed that this extract includes phenolic and flavonoid compounds. The total phenolic value was more than total flavonoids compounds. The anti-Leishmania activity of M. sativa extract may be due to the high concentration of phenolic compounds, especially caffeic acid. From our results, it can be suggested that the M. sativa extract is a potential herbal drug against leishmaniasis.

Key words: IC50, Leishmania, Medicago sativa, phenols,flavonoids, wound healing

Gram variable Streptococcus dysgalactiae subsp. equisimilis recovered from a suppurative peritoneal effusion of a dog

Georgios Meletis1, Christina Marouda1, Georgios Tzimagiorgis2, Maria Chatzidimitriou3, Ioannis Rintis4,
Dimitrios Chatzidimitriou1,5

1.Labnet laboratories, Thessaloniki, Greece
2.Laboratory of Biological Chemistry, School of Health Sciences, Medical Department, Aristotle University of
Thessaloniki, Greece
3.Biomedical Sciences Alexander Campus, International Hellenic University, Thessaloniki, Greece
4.Private veterinary practice, Giannitsa, Greece
5.Laboratory of Microbiology, Medical School, Aristotle University of Thessaloniki, Greece

Key words: Streptococcus dysgalactiae; Gram variability;group C Streptococcus; peritoneal effusion

Acute diarrhea associated with Dientamoeba fragilis and Clostridioides difficile coinfection: A laboratory diagnostic challenge

Constantine M. Vassalos1, Evdokia Vassalou2, Lazaros Tsoukalas1,2, Evangelia Lakaki1,
Aikaterini Masgala3, Helen Merkouri1, Dimitra N. Manthou2

1.Dpt. of Microbiology, General Hospital of Nea Ionia “Konstantopouleio-Patision”, Athens, Greece
2.Dpt. Of Public and Community Health, School of Public Health, University of West Attica, Athens, Greece
3.1st Dpt. of Internal Medicine, General Hospital of Nea Ionia “Konstantopouleio-Patision”, Athens, Greece

Acute infectious diarrhea is a common health problem among adults. It is mainly associated with bacterial or viral infections. Clinical and laboratory investigation can be challenging. It is possible that instead of one infectious agent, other agents, not easily recognized, can be also responsible for acute diarrhea manifestation. Herein, a case of community-acquired acute diarrhea
due to a rare coinfection with an intestinal protozoan (Dientamoeba fragilis) and an anaerobic bacterium (Clostridioides difficile) coinfection in an elderly patient is described.

Key words:Dientamoeba fragilis, Clostridioides difficile, coinfection, community-acquired diarrhea