Antibacterial Effect of Eight Essential Oils against Bacteria Implicated in Bovine Mastitis and Characterization of Primary Action Mode of Essential Oil.

During the current investigation, eight essential oils (EOs) were tested for their antimicrobial activity against six species, belonging to the genus of , multi-resistant to antibiotics (, , , , , ), three methicillin-resistant strains (MRSA) and two strains of producing extended-spectrum β-lactamase (ESBL) responsible for bovine mastitis. Our results indicated that the antimicrobial activities of eight EOs varied significantly among the types of EOs and bacterial species. and EOs display important antibacterial activity against all tested strains, with the inhibition zone diameters situated between 20 and 45 mm, while EOs of , , , and exerted an intermediate activity.

Methicillin-Resistant Strains Isolated from Burned Patients in a Tunisian Hospital: Molecular Typing, Virulence Genes, and Antimicrobial Resistance.

Methicillin-resistant (MRSA) is one of the major causes of a variety of infections in hospitals and the community. Their spread poses a serious public health problem worldwide. Nevertheless, in Tunisia and other African countries, very little molecular typing data on MRSA strains is currently available.

Lineages, Virulence Gene Associated and Integrons among Extended Spectrum β-Lactamase (ESBL) and CMY-2 Producing from Bovine Mastitis, in Tunisia.

Extended Spectrum Beta-Lactamase (ESBL) Enterobacteriaceae are becoming widespread enzymes in food-producing animals worldwide. Escherichia coli and Klebseilla pneumoniae are two of the most significant pathogens causing mastitis. Our study focused on the characterization of the genetic support of ESBL/pAmpC and antibiotic resistance mechanisms in cefotaxime-resistant (CTXR) and susceptible (CTXS) Enterobacteriaceae isolates, recovered from bovine mastitis in Tunisia, as well as the analyses of their clonal lineage and virulence-associated genes.

Characterization of Primary Action Mode of Eight Essential Oils and Evaluation of Their Antibacterial Effect against Extended-Spectrum β-Lactamase (ESBL)-Producing Inoculated in Turkey Meat.

The current study aims to evaluate the antimicrobial activity of eight essential oils (EOs) against multidrug-resistant strains, producing extended-spectrum β-lactamase (ESBL) enzymes and isolated from foods. Disc-diffusion assay showed that the inhibition diameters generated by EOs varied significantly among the tested EOs and strains. In fact, EOs extracted from , , and exerted an important antimicrobial effect against tested strains, with the diameters of inhibition zones varied between 20 and 27 mm.

First Detection of Human ST131-CTX-M-15-O25-B2 Clone and High-Risk Clonal Lineages of ESBL/pAmpC-Producing Isolates from Diarrheic Poultry in Tunisia.

Circulation of a multi-resistance clone of bacteria associated with genetic elements in diseased animals constitutes a global public health problem. Our study focused on the characterization of the support of ESBL in cefotaxime resistant (CTX) isolates recovered from poultry with diarrhea, analysis of their clonal lineage, and virulence-associated genes. The study was carried out on 130 samples of chickens with diarrhea, collected in 2015 from poultry farms in Tunisia.

Detection of Extended-Spectrum -Lactamases (ESBL) Producing Enterobacteriaceae from Fish Trapped in the Lagoon Area of Bizerte, Tunisia.

Extended-spectrum -lactamase and their molecular mechanism in were analyzed in 126 fish samples of 9 various wild species, living in the lagoon of Bizerte in Tunisia. Fifty-nine (59) Gram-negative strains were isolated and identified as ( = 24), ( = 21), ( = 8), and ( = 6). Forty-seven ESBL producers were identified using the synergic test.

Antimicrobial resistance genes and virulence gene encoding intimin in and isolated from wild rabbits () in Tunisia.

The spread of antimicrobial-resistant bacteria in wildlife must be viewed as a major concern with serious implications for human and animal health. and enterococcal isolates were recovered from faecal samples of 49 wild rabbits on specific media and were characterised using biochemical and molecular tests. For all isolates, antimicrobial susceptibility testing was performed, and resistance genes were detected by PCR.

Epidemiology of -Lactamase-Producing Staphylococci and Gram Negative Bacteria as Cause of Clinical Bovine Mastitis in Tunisia.

The aim of this study was to determine the species distribution of Gram negative bacteria (GNB) and the occurrence of Methicillin Resistant Staphylococci (MRS) and Extended-Spectrum -lactamase- (ESBL-) producing GNB. Bacterial culture of 300 clinical mastitis milk samples from 30 different farms across different regions of Tunisia during four seasons was realized. The obtained results showed the presence of high frequency of the tested samples with a positive growth for bacteria (64%).

Prevalence and Antibiotic Resistance Patterns of spp. Isolated from Broiler Chickens in the North of Tunisia.

The aim of the current study is to assess the prevalence of infection in broiler chickens, raised in intensive production conditions, and to evaluate the antimicrobial susceptibility of recovered isolates. A total of 590 cloacal swab samples were taken from 13 broiler chicken flocks in the North East of Tunisia. All samples were tested for the presence of thermophilic by culture and PCR, targeting the and genes, respectively.

Detection and characterization of methicillin-resistant and susceptible coagulase-negative staphylococci in milk from cows with clinical mastitis in Tunisia.

Objectives: This study investigated prevalence of methicillin-resistant (MR) and methicillin-susceptible (MS) coagulase-negative staphylococci (CNS) and the implicated mechanisms of resistance and virulence in milk of mastitis cows. In addition, the presence of SCCmec type was analyzed in MR Staphylococcus epidermidis (MRSE).

Results: Three hundred milk samples from cows with clinical mastitis were obtained from 30 dairy farms in different regions of Tunisia.

Molecular Characterization and Clonal Diversity of Methicillin-Resistant and -Susceptible Staphylococcus aureus Isolates of Milk of Cows with Clinical Mastitis in Tunisia.

The aim of this study was to determine the genetic lineages, and the frequency of antibiotic resistance and virulence determinants in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) isolates recovered from milk of cows with clinical mastitis. Three hundred milk samples from bovine with clinical mastitis were obtained from 30 dairy farms in different regions of Tunisia.

First Detection of CTX-M-1 in Extended-Spectrum β-Lactamase-Producing Escherichia coli in Seafood from Tunisia.

The purpose of this study was to determine the carriage rate of Escherichia coli isolates in seafood, to analyze the phenotype and genotype of antimicrobial resistance in the recovered isolates, and to characterize extended-spectrum β-lactamase (ESBL) E. coli producers. E.

Detection of CTX-M-15-Producing Escherichia coli Isolates of Lineages ST131-B2 and ST167-A in Environmental Samples of a Tunisian Hospital.

To investigate the possible role of the hospital environment in the dissemination of extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli isolates, 300 samples were taken during 2013 from abiotic surfaces (n = 250), healthcare worker hands (n = 27), and hands of patients (n = 23) in a Tunisian Hospital. ESBL-producing E. coli isolates were recovered in 3.

Characteristics of extended-spectrum β-lactamase (ESBL)- and pAmpC beta-lactamase-producing Enterobacteriaceae of water samples in Tunisia.

The presence of extended-spectrum beta-lactamase and plasmid-mediated AmpC beta-lactamase producing Enterobacteriaceae (ESBL-Eb and pAmpC-Eb, respectively) was analyzed in 57 wastewater and 57 surface-water samples in Tunisia. Twenty-four of the 57 wastewater samples (42.1%) and one of the 57 surface-water samples (1.

Detection of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in vegetables, soil and water of the farm environment in Tunisia.

One-hundred-nine samples of 18 different farms (49 of food-vegetables, 41 of soil and 19 of irrigation water) and 45 vegetable food samples of 13 markets were collected in Tunisia. These samples were inoculated in MacConkey agar plates supplemented with cefotaxime (2 μg/ml). ESBL-producing Enterobacteriaceae (ESBL-Eb) were detected in 10 of the 109 farm samples (vegetables, 8.

IncI1 plasmids carrying bla(CTX-M-1) or bla(CMY-2) genes in Escherichia coli from healthy humans and animals in Tunisia.

The objective was to determine the location of bla(CTX-M-1) and bla(CMY-2) genes in 33 Escherichia coli isolates previously obtained from healthy humans, pets, and food-producing animals in Tunisia, and to characterize the genetic lineages of isolates. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE)-XbaI and multilocus sequence typing (MLST). Plasmids were analyzed by S1-PFGE, polymerase chain reaction-based replicon typing, and plasmid MLST.

Antimicrobial resistance, virulence genes, and genetic lineages of Staphylococcus pseudintermedius in healthy dogs in tunisia.

Nasal swabs of 100 healthy dogs were obtained in 2011 in Tunisia and tested for Staphylococcus pseudintermedius recovery. Antimicrobial resistance profile and virulence gene content were determined. Multilocus-sequence-typing (MLST) and SmaI-pulsed-field gel electrophoresis (PFGE) were investigated.

Hydrocarbonoclastic bacteria isolated from petroleum contaminated sites in Tunisia: isolation, identification and characterization of the biotechnological potential.

Petroleum hydrocarbons are important energy resources used by industry and in our daily life, whose production contributes highly to environmental pollution. To control such risk, bioremediation constitutes an environmentally friendly alternative technology that has been established and applied. It constitutes the primary mechanism for the elimination of hydrocarbons from contaminated sites by natural existing populations of microorganisms.

Lineages and virulence gene content among extended-spectrum β-lactamase-producing Escherichia coli strains of food origin in Tunisia.

Nineteen extended-spectrum β-lactamase (ESBL)-positive Escherichia coli strains recovered from food samples in Tunisia were characterized by multilocus sequence typing and phylogenetic typing, and the virulence gene and plasmid content were also determined. These strains presented unrelated pulsed-field gel electrophoresis patterns and contained genes coding for the following ESBLs (the number of strains is in parentheses): CTX-M-1 (15), CTX-M-14 (2), CTX-M-8 (1), and SHV-5 (1). Twelve different sequence types (STs) were identified among the 19 ESBL-positive strains, which included two new STs (ST2022 in 2 bla(CTX-M-14)-containing strains and ST1970 in 2 bla(CTX-M-1)-containing strains).

First detection of CTX-M-1, CMY-2, and QnrB19 resistance mechanisms in fecal Escherichia coli isolates from healthy pets in Tunisia.

Our objective was to analyze the carriage rate of extended-spectrum β-lactamase (ESBL)- and plasmidic AmpC β-lactamase (pAmpC)-producing Escherichia coli isolates in fecal samples of healthy pets (dogs and cats) and to characterize the recovered isolates for the presence of other resistance genes and integrons. Eighty fecal samples of healthy pets were inoculated in MacConkey agar plates supplemented with cefotaxime (2 μg/mL) for cefotaxime-resistant (CTX(R)) E. coli recovery.

Species distribution, antibiotic resistance and virulence traits in enterococci from meat in Tunisia.

Antimicrobial resistance and the mechanisms implicated were studied in 119 enterococci from 105 meat samples from Tunisian markets. Almost 24.5% of recovered enterococci showed resistance against four or more antimicrobial agents and these isolates were identified to the species level.

Prevalence and characterization of extended-spectrum beta-lactamase (ESBL)- and CMY-2-producing Escherichia coli isolates from healthy food-producing animals in Tunisia.

The prevalence of extended-spectrum beta-lactamase (ESBL)- and plasmidic AmpC-beta-lactamase (pAmpC-BL)-producing Escherichia coli isolates has been studied in food-producing animals at the farm level in Tunisia, and recovered isolates were characterized for the presence of other resistance genes and integrons. Eighty fecal samples of food-producing animals (23 sheep, 22 chickens, 22 cattle, six horses, five rabbits, and two dromedaries) were obtained from 35 different farms in Tunisia in 2011. Samples were inoculated onto MacConkey agar plates supplemented with cefotaxime (2 mg/L) for cefotaxime-resistant (CTX(R)) E.

High diversity of genetic lineages and virulence genes in nasal Staphylococcus aureus isolates from donkeys destined to food consumption in Tunisia with predominance of the ruminant associated CC133 lineage.

Background: The objective of this study was to determine the genetic lineages and the incidence of antibiotic resistance and virulence determinants of nasal Staphylococcus aureus isolates of healthy donkeys destined to food consumption in Tunisia.

Results: Nasal swabs of 100 donkeys obtained in a large slaughterhouse in 2010 were inoculated in specific media for S. aureus and methicillin-resistant S.

Diversity of genetic lineages among CTX-M-15 and CTX-M-14 producing Escherichia coli strains in a Tunisian hospital.

Fourteen broad-spectrum-cephalosporin-resistant Escherichia coli isolates were recovered between June and December 2007 in a Tunisian hospital. Genes encoding extended-spectrum-beta-lactamases (ESBL) and other resistance genes were characterized by PCR and sequencing. The following ESBL genes were identified: bla (CTX-M-15) (12 isolates), bla (CTX-M-14a) (one isolate), and bla (CTX-M-14b) (one isolate).