Marios Lysitsas

Mr. Marios Lysitsas

Faculty of Veterinary Sciences University of Thessaly, Kardítsa, Thessalía, Greece
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Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 October 2023 in Veterinary Sciences
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Marios LysitsasMarios Lysitsas
Marios Lysitsas
ETEleutherios Triantafillou
Eleutherios Triantafillou
Irene ChatzipanagiotidouIrene Chatzipanagiotidou
Irene Chatzipanagiotidou
KAKonstantina Antoniou
Konstantina Antoniou
George ValiakosGeorge Valiakos
George Valiakos
Acinetobacter baumannii–calcoaceticus (Abc) Complex bacteria are troublesome nosocomial pathogens in human medicine, especially during the last 30 years. Recent research in veterinary medicine also supports its emergence as an animal pathogen. However, relevant data are limited. In this study, we obtained 41 A. baumannii isolates from clinical samples of canine and feline origin collected in veterinary clinics in Greece between 2020 and 2023. Biochemical identification, antimicrobial susceptibility testing, molecular identification and statistical analysis were performed. Most of the samples were of soft tissue and urine origin, while polymicrobial infections were recorded in 29 cases. Minocycline was the most effective in vitro antibiotic, whereas high resistance rates were detected for almost all the agents tested. Notably, 20 isolates were carbapenem resistant and 19 extensively drug resistant (XDR). This is the first report of canine and feline infections caused by Abc in Greece. The results create concerns regarding the capability of the respective bacteria to cause difficult-to-treat infections in pets and persist in veterinary facilities through hospitalized animals, contaminated equipment, and surfaces. Moreover, the prevalence of highly resistant strains in companion animals constitutes a public health issue since they could act as a reservoir, contributing to the spread of epidemic clones in a community.

Verified
Journal Article
Open access
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Marios LysitsasMarios Lysitsas
Marios Lysitsas
ETEleutherios Triantafillou
Eleutherios Triantafillou
Irene ChatzipanagiotidouIrene Chatzipanagiotidou
Irene Chatzipanagiotidou
KAKonstantina Antoniou
Konstantina Antoniou
VSVassiliki Spyrou
Vassiliki Spyrou
George ValiakosGeorge Valiakos
George Valiakos
Bacteria of the genus Acinetobacter, especially Acinetobacter baumannii (Ab), have emerged as pathogens of companion animals during the last two decades and are commonly associated with hospitalization and multidrug resistance. A critical factor for the distribution of relevant strains in healthcare facilities, including veterinary facilities, is their adherence to both biotic and abiotic surfaces and the production of biofilms. A group of 41 A. baumannii isolates obtained from canine and feline clinical samples in Greece was subjected to phenotypic investigation of their ability to produce biofilms using the tissue culture plate (TCP) method. All of them (100%) produced biofilms, while 23 isolates (56.1%) were classified as strong producers, 11 (26.8%) as moderate producers, and 7 (17.1%) as weak producers. A correlation between the MDR and XDR phenotypes and weak or moderate biofilm production was identified. Moreover, the presence of four biofilm-associated genes bap, blaPER, ompA, and csuE was examined by PCR, and they were detected in 100%, 65.9%, 97.6%, and 95.1% of the strains respectively. All isolates carried at least two of the investigated genes, whereas most of the strong biofilm producers carried all four genes. In conclusion, the spread and persistence of biofilm-producing Ab strains in veterinary facilities is a matter of concern, since they are regularly obtained from infected animals, indicating their potential as challenging pathogens for veterinarians due to multidrug resistance and tolerance in conventional eradication measures. Furthermore, considering that companion animals can act as reservoirs of relevant strains, public health concerns emerge.

14 August 2024 in Microorganisms
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IGIOANNIS GOUVIAS
IOANNIS GOUVIAS
Marios LysitsasMarios Lysitsas
Marios Lysitsas
ABApostolos Batsidis
Apostolos Batsidis
SMSonia Malefaki
Sonia Malefaki
DBDimitra Bitchava
Dimitra Bitchava
George ValiakosGeorge Valiakos
George Valiakos
The objective of this study was to apply and preliminarily evaluate a High-Resolution Melting (HRM) analysis technique coupled with qPCR, that allows the simultaneous detection of 10 different ruminant abortogenic pathogens, for investigating abortions in sheep and goats throughout Greece. A total of 264 ovine and caprine vaginal swabs were obtained the week following the abortion from aborted females and analyzed using a commercially available kit (ID Gene™ Ruminant Abortion Multiplex HRM, Innovative Diagnostics). Results indicated a high prevalence of Coxiella burnetii and Chlamydophila spp., which were detected in 48.9% and 42.4% of the vaginal swabs, respectively. Results for these most commonly detected pathogens were compared with those of a well-established commercial qPCR kit, with near-perfect agreement. Toxoplasma gondii, Salmonella spp., Brucella spp., Anaplasma phagocytophilum, Campylobacter fetus, and Neospora caninum were also identified, the two latter reported for the first time in the country in small ruminants. Mixed infections occurred in 35.6% of the animals examined. This technique allows for the simultaneous detection of many abortogenic pathogens in an accurate and cost-effective assay. Detection of uncommon or not previously reported pathogens in various cases indicates that their role in ovine and caprine abortions may be underestimated.

25 November 2023 in Antibiotics
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Marios LysitsasMarios Lysitsas
Marios Lysitsas
VSVassiliki Spyrou
Vassiliki Spyrou
CBCharalambos Billinis
Charalambos Billinis
George ValiakosGeorge Valiakos
George Valiakos
The objective of this review is to investigate the distribution and the characteristics of coagulase-negative Staphylococci (CoNS) implicated in ovine mastitis, and especially in subclinical cases, in order to provide a global perspective of the current research data and analyze specific critical aspects of the issue. PRISMA guidelines were implemented in the search of the last 20 years of the related literature in two databases. In total, 139 studies were included in this review. Relevant data were tracked down, assembled, and compared. Regarding the geographical distribution, most studies originated from Europe (68), followed by South America (33). Lacaune was the most examined breed, while S. epidermidis was the predominantly identified species, representing approximately 39% of the obtained isolates. Antibiotic resistance in the relevant bacteria was documented mostly for Penicillin (32.8%) and Amoxicillin (32.1%), while biofilm- and toxin-associated genes were encountered in variable rates because significant inequalities were observed between different articles. Significantly higher rates of antimicrobial resistance were detected in Asia and South America compared to Europe. Finally, the diagnostic procedures carried out in the respective studies were evaluated. Conventional culture and biochemical tests were mostly performed for simple strain identification; therefore, further molecular investigation of isolates should be pursued in future studies, as this will provide important data regarding specific aspects of the implication of CoNS in ovine mastitis.

9 May 2023 in Veterinary Sciences
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Marios LysitsasMarios Lysitsas
Marios Lysitsas
Irene ChatzipanagiotidouIrene Chatzipanagiotidou
Irene Chatzipanagiotidou
CBCharalambos Billinis
Charalambos Billinis
George ValiakosGeorge Valiakos
George Valiakos
Fosfomycin is an old antibacterial agent, which is currently used mainly in human medicine, in uncomplicated Urinary Tract Infections (UTIs). The purpose of this review is to investigate the presence and the characteristics of Fosfomycin resistance in bacteria isolated from canine or feline samples, estimate the possible causes of the dissemination of associated strains in pets, and underline the requirements of prospective relevant studies. Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines were used for the search of current literature in two databases. A total of 33 articles were finally included in the review. Relevant data were tracked down, assembled, and compared. Referring to the geographical distribution, Northeast Asia was the main area of origin of the studies. E. coli was the predominant species detected, followed by other Enterobacteriaceae, Staphylococci, and Pseudomonas spp. FosA and fosA3 were the more frequently encountered Antimicrobial Resistance Genes (ARGs) in the related Gram-negative isolates, while fosB was regularly encountered in Gram-positive ones. The majority of the strains were multidrug-resistant (MDR) and co-carried resistance genes against several classes of antibiotics and especially β-Lactams, such as blaCTX-M and mecA. These results demonstrate the fact that the cause of the spreading of Fosfomycin-resistant bacteria among pets could be the extended use of other antibacterial agents, that promote the prevalence of MDR, epidemic strains among an animal population. Through the circulation of these strains into a community, a public health issue could arise. Further research is essential though, for the comprehensive consideration of the issue, as the current data are limited.

25 April 2024 in Microbiology Research
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George ValiakosGeorge Valiakos
George Valiakos
IGIOANNIS GOUVIAS
IOANNIS GOUVIAS
Marios LysitsasMarios Lysitsas
Marios Lysitsas
IBIlias Georgios Bouzalas
Ilias Georgios Bouzalas
STStefania Tampach
Stefania Tampach
CBCharalambos Billinis
Charalambos Billinis
The exposure of dairy cows to Coxiella burnetii using molecular and serological techniques was investigated in this study. Bulk tank milk and serum samples were collected from various farms in Greece (mainly northern Greece). DNA extraction was performed on milk samples, and qPCR targeting the IS1111 insertion sequence was performed to detect bacterial pathogens. An ELISA was used to detect specific antibodies in bulk milk and individual serum samples. Data on farms were collected in the field using handheld Global Positioning System Garmin units. The collected data were analyzed using an Ecological Niche Model within the framework of a geographic information system. The results indicated that in more than half of the dairy farms (35/60, 58.3%), C. burnetii is present in milk. Specific antibodies were also detected in almost all milk samples (57/60, 95.0%). At least one seropositive animal was identified using ELISA in the majority of the examined farms (25/28, 89.3%). C. burnetii PCR-positive farms were located in the low-altitude zone with a mean value of 97 m above sea level (range: 2–681). The environmental variable with the highest gain when used in isolation is precipitation in the wettest quarter (28.3% contribution), which therefore appears to have the most useful information by itself. The environmental variable that decreases the gain the most when omitted is the minimal temperature of the coldest month (6.9% contribution). The analysis demonstrated that a mild climate with low precipitation favors a positive status. The exposure of dairy cattle farms to C. burnetii is massive, raising significant concerns regarding livestock production and public health implications.