Ammar Ayachi

Prof. Dr. Ammar Ayachi


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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30 April 2019 in The Journal of Infection in Developing Countries
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MMMANEL MERRADI
MANEL MERRADI
AKAhmed Kassah-Laouar
Ahmed Kassah-Laouar
AAAmmar Ayachi
Ammar Ayachi
NHNouzha Heleili
Nouzha Heleili
Taha MenasriaTaha Menasria
Taha Menasria
MSMarlène Sauget
Marlène Sauget
Introduction: Pseudomonas aeruginosa is one of the most common nosocomial pathogens, known with a wide resistance to antimicrobials. Carbapenemases producing Pseudomonas aeruginosa is a growing global public health concern as this pathogen is easily transmissible among patients. Metallo-Beta-lactamases is the most important class of these carbapenemases with their broad-spectrum resistance profile. This study was conducted to investigate the prevalence of MBL-producing P. aeruginosa collected in an Algerian hospital. Methodology: All Metallo-β-lactamase (MBL)-producing P. aeruginosa isolates recovered from patients during a 2 years period (2015-2016) were studied using a combination of phenotypic and molecular typing methods (susceptibility testing, molecular characterization of carbapenemase-encoding genes, multi-locus sequence typing and pulsed-field gel electrophoresis). Results: A total of twenty-six MBL producing P. aeruginosa of 188 isolates were investigated. The burns unit ranked in the first position of the majority of identified cases with 73.07%. About 73.07% of total MBL isolates were mainly isolated from pus samples. The studied isolates were subjected to the molecular typing, in which 4 different Dra1-PFGE patterns and 3 sequences type were assigned (ST244, ST381, and ST1076), and all isolates were revealed positive for VIM-4. Conclusions: We report the third description of blaVIM-4 in Algeria indicating the emergence and spread of carbapenemase-encoding genes among P. aeruginosa in the hospital environment.

29 October 2015 in The Journal of Infection in Developing Countries
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AAAmmar Ayachi
Ammar Ayachi
OBOmar Bennoune
Omar Bennoune
NHNouzha Heleili
Nouzha Heleili
NANadir Alloui
Nadir Alloui
Introduction: Salmonellosis is one of the major foodborne diseases known to be closely related to the consumption of contaminated eggs, infected poultry, and poultry products. Control and survey of the poultry chain are the key elements and the most critical steps in the prevention of human transmission of Salmonella. Methodology: This study was carried out in East Algeria on 150 eggs meant for consumption collected from mini-markets and immediately tested for Salmonella using standard methods (ISO AFNOR 6579 modified in 2002). Briefly, the shell surfaces were carefully wiped using sterile appropriated tissues while the white and yellow yolks were separated. All 10 samples were pooled together and a total of 45 samples were carefully analyzed. Results: A contamination rate of 4.4% was found, and two strains of Salmonella bradford were isolated from white and yellow yolks. The results showed that XLT4 was the best medium for Salmonella isolation from yolks. Screening for other Salmonella in parental chickens using an enzyme-linked immunosorbent assay (ELISA) test revealed seropositive cases of Salmonella enteritidis at the top of the poultry production pyramid. Conclusions: Occurrence of Salmonella in yolks and seropositive results for S. in parental chickens is a serious and potential danger to public health. Radical and preventive measures must be taken at the critical points to control and to avoid human transmission. These measures must be installed at all levels of egg production through the application of appropriate and strict regulations, and use of good hygienic practices in transport, storage, and food preparation.

5 September 2017 in The Journal of Infection in Developing Countries
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BDBilal Djeghout
Bilal Djeghout
AAAmmar Ayachi
Ammar Ayachi
BPBianca Paglietti
Bianca Paglietti
GLGemma Langridge
Gemma Langridge
SRSalvatore Rubino
Salvatore Rubino
Non-typhoidal Salmonella (NTS) represents a leading cause of food-borne disease worldwide. It is a global public health concern: more than 94 million cases and 115,000 deaths are reported every year, with a disproportionate impact in developing countries. The prevalence of multi-drug-resistant (MDR) Salmonella strains is another major health concern which affects antimicrobial treatment, as many studies report that infections caused by MDR strains are more severe than those caused by susceptible strains. In Algeria, NTS represent one of the primary causes of salmonellosis in both humans and food animal production, especially poultry. Epidemiological surveillance systems and monitoring programs for Salmonella infections are essential requirements to provide data useful for the effective detection and control of Salmonella outbreaks. The present review will supply a perspective on NTS infection, pathogenesis and antimicrobial resistance with a focus on the epidemiology of salmonellosis in Algeria.

1 March 2018 in Veterinary World
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Journal Article
Open access
MMMerradi Manel
Merradi Manel
HNHeleili Nouzha
Heleili Nouzha
MRMekari Rim
Mekari Rim
MIMekkaoui Imane
Mekkaoui Imane
ASAouachria Sana
Aouachria Sana
AAAmmar Ayachi
Ammar Ayachi
Aim: This work aimed to evaluate the biological activity of the leaf extracts of uniperus thurifera L., which is an Algerian endemic tree that belongs to the family of Cupressaceae. Materials and Methods: The plant leaves were extracted in solvents of increasing polarity to obtain differentextracts such as methanol, petroleum ether, chloroform, ethyl acetate, and aqueous extracts (MeE, PEE, ChlE, EtAE, and AqE). The antioxidant activity of four extracts (MeE, Ch1E, EtAE, and AqE) was assessed by trapping test of 1,1-dipheny1-2-picrylhydrazyl (DPPH) radical. The evaluation of antibacterial activity of MeE, Ch1E, EtAE, and PEE was done using the disk diffusion method on solid agar. Results: The three extracts of EtAE, AqE, and MeE showed high antiradical activity toward the DPPH radical (IC50=29.348 mu g/mL, 37.538 mu g/mL, and 52.573 mu g/mL, respectively), while the lowest radical scavenging activity was expressed by the ChIE (IC50=70.096 mu g/mL). These extracts were active only toward the Gram-positive bacteria (Staphylococcus aureus ATCC and methicillin-resistant S. aureus) at different concentrations, and the highest activity was obtained with the ChlE with an inhibition diameter of 14 mm at the concentration of 1 g/mL. No inhibition was detected for all of these extracts against the Gram-negative tested strains (Escherichia coil ATCC, Pseudomonas aeruginosa ATCC, and Enterobacter cloacae (extended spectrum beta-lactamase). Conclusion: From this study, on the one hand, it was concluded that J. thurifera L. leaves extracts exhibited a very intense antioxidant potential toward the DPPH radical, and on the other hand, the antibacterial activity showed an action spectrum exclusively toward the Gram-positive bacteria.

24 February 2025 in Antibiotics
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ABAmina BADIS
Amina BADIS
NHNouzha Heleili
Nouzha Heleili
MMMANEL MERRADI
MANEL MERRADI
AAAmmar Ayachi
Ammar Ayachi
PMPiera Anna Martino
Piera Anna Martino
ASalessio soggiu
alessio soggiu
Background/Objectives: Pseudomonas aeruginosa causes chronic infections in humans and animals, especially cats and dogs. This bacterium’s ability to adapt and acquire antibiotic resistance traits may complicate and exacerbate antibacterial therapy. This study aimed to evaluate the antibiotic resistance patterns, virulence factors and ability to form biofilms of P. aeruginosa strains isolated from Algerian dogs and cats. Methods: Nineteen samples were collected from healthy and diseased dogs and cats. Isolates were studied for their antibiotic-resistance patterns (disc diffusion method) and biofilm formation (Microtiter assay) and were whole-genome sequenced (MinION). Results: Nineteen P. aeruginosa strains (15 from dogs and 4 from cats) were isolated. Antibiotic-resistance phenotypes were observed against amoxicillin–clavulanic acid (100%); meanwhile, resistance towards ticarcillin was 40% (dogs) and 25% (cats), ticarcillin–clavulanic acid was 13.33% and 25% for dogs and cats, respectively, and imipenem was 75% (cats) and 20% (dogs). Moreover, 95% of strains were biofilm-producers. Different antimicrobial resistance genes (ARGs) were found: beta-lactamase genes, mainly PAO, OXA-494, OXA-50 and OXA-396 and an aminoglycoside gene (aph(3′)-IIb). The main high-risk sequence types (STs) were ST244, 2788, 388 and 1247. A large panel of virulence genes was detected: exoS, exoT, exoY, lasA, toxA, prpL, algD, rhIA and others. Conclusions: The genetic variety in antibiotic-resistance genes of resistant and virulent P. aeruginosa strains in dogs makes public health protection difficult. Continuous monitoring and research in compliance with the One Health policy are needed to solve this problem.

1 January 2013 in Journal of Veterinary Advances
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NHNouzha Heleili
Nouzha Heleili
AAAmmar Ayachi
Ammar Ayachi
BMBakir Mamache
Bakir Mamache
AKAhmed Kassah
Ahmed Kassah