Search

The chemical composition, investigated by gas chromatography-mass spectrometry, and antibacterial activity of lipophilic extractives of three varieties of Opuntia ficus-indica roots from Algeria are reported in this paper for the first time. The results obtained revealed a total of 55 compounds, including fatty acids, sterols, monoglycerides and long chain aliphatic alcohols that were identified and quantified. β-Sitosterol was found as the major compound of the roots of the three varieties. Furthermore, considerable amounts of essential fatty acids (ω3, ω6, and ω9) such as oleic, linoleic, and linolenic acids were also identified. The green variety was the richest among the three studied varieties. The antibacterial activity, evaluated with disc diffusion method, revealed that lipophilic extracts were effective mainly against Gram-positive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) (19~23 mm). Gram-negative strains mainly Pseudomonas aeruginosa gave an inhibition zone of 18 mm, which is considered high antibacterial activity. The minimal inhibitory concentrations of the tested bacteria revealed interesting values against the majority of bacteria tested: 75-100 µg mL -1 for Bacillus sp., 250-350 µg/mL for the two Staphylococcus strains, 550-600 µg mL -1 for E. coli , and 750-950 µg mL -1 obtained with Pseudomonas sp. This study allows us to conclude that the lipophilic fractions of cactus roots possess interesting phytochemicals such as steroids, some fatty acids and long chain alcohols that acted as antibiotic-like compounds countering pathogenic strains.

Background: Staphylococcus aureus can colonize and infect a variety of animal species. In dairy herds, it is one of the leading causes of mastitis cases. The objective of this study was to characterize the S. aureus isolates recovered from nasal swabs of 249 healthy cows and 21 breeders of 21 dairy farms located in two provinces of Algeria (Tizi Ouzou and Bouira). Methods: The detection of enterotoxin genes was investigated by multiplex PCRs. Resistance of recovered isolates to 8 antimicrobial agents was determined by disc-diffusion method. The slime production and biofilm formation of S. aureus isolates were assessed using congo-red agar (CRA) and microtiter-plate assay. Molecular characterization of selected isolates was carried out by spa-typing and Multi-Locus-Sequence-Typing (MLST). Results: S. aureus was detected in 30/249 (12%) and 6/13 (28.6%) of nasal swabs in cows and breeders, respectively, and a total of 72 isolates were recovered from positive samples (59 isolates from cows and 13 from breeders). Twenty-six of these isolates (36.1%) harbored genes encoding for staphylococcal enterotoxins, including 17/59 (28.8%) isolates from cows and 9/13 (69.2%) from breeders. Moreover, 49.1% and 92.3% of isolates from cows and breeders, respectively, showed penicillin resistance. All isolates were considered as methicillin-susceptible (MSSA). Forty-five (76.3%) of the isolates from cows were slime producers and 52 (88.1%) of them had the ability to form biofilm in microtiter plates. Evidence of a possible zoonotic transmission was observed in two farms, since S. aureus isolates recovered in these farms from cows and breeders belonged to the same clonal lineage (CC15-ST15-t084 or CC30-ST34-t2228). Conclusions: Although healthy cows in this study did not harbor methicillin-resistant S. aureus isolates, the nares of healthy cows could be a reservoir of enterotoxigenic and biofilm producing isolates which could have implications in human and animal health. [ABSTRACT FROM AUTHOR]

The present study aimed to determine the phenotypic and genotypic characteristics of S. aureus isolates from the nasal swabs of goats. A total of 232 nasal samples (one per animal) were collected from goats on 13 farms located in two regions of Algeria and were analyzed for the presence of S. aureus. The detection of virulence factors was carried out using PCR. The antibiotic susceptibility of the recovered isolates was assessed using the disc diffusion method. The biofilm formation ability was assessed by the Congo red agar method and a microtiter plate assay, and the molecular characterization of isolates was carried out by spa-typing, and for selected isolates also by multilocus sequence typing (MLST). Overall, 36 out of 232 nasal swabs (15.5%) contained S. aureus, and 62 isolates were recovered. Regarding the virulence factors, at least one staphylococcal enterotoxin gene was detected in 30 (48.4%) isolates. The gene tst encoding the toxic shock syndrome toxin was detected in fifteen isolates (24.2%), but none of the isolates harbored the gene of Panton–Valentine leukocidin (lukF/S-PV). Nine different spa-types were identified, including the detection of a new one (t21230). The recovered isolates were assigned to three clonal complexes, with CC5 (51.8%) being the most common lineage. Two isolates were methicillin-resistant (MRSA) and belonged to ST5 (CC5) and to spa-types t450 and t688. Moreover, 27 (43.5%) of the S. aureus isolates were found to be slime producers in Congo red agar, and all of the recovered isolates could produce biofilms in the microtiter plate assay. Our study showed that the nares of healthy goats could be a reservoir of toxigenic and antibiotic-resistant strains of S. aureus isolates, including MRSA, which could have implications for public health. [ABSTRACT FROM AUTHOR]

Methicillin resistance, mediated by the mecA gene in staphylococci and mammaliicocci, has caused tremendous setbacks in the use of antibiotics in human and veterinary medicine due to its high potential of presenting the multidrug resistance (MDR) phenotype. Three other mec analogs exist, of which the mecC has evolutionary been associated with methicillin-resistant Staphylococcus aureus (MRSA) in wild animals, thus loosely referred to as the wild MRSA. In this study, we present an epidemiological review and genomic analysis of non-aureus staphylococci and mammaliicocci that carry the mecC-mediated methicillin resistance trait and determine whether this trait has any relevant link with the One Health niches. All previous studies (2007 till 2023) that described the mecC gene in non-aureus staphylococci and mammaliicocci were obtained from bibliometric databases, reviewed, and systematically analyzed to obtain the antimicrobial resistance (AMR) and virulence determinants, mobilome, and other genetic contents. Moreover, core genome single-nucleotide polymorphism analysis was used to assess the relatedness of these strains. Of the 533 articles analyzed, only 16 studies (on livestock, environmental samples, milk bulk tanks, and wild animals) were eligible for inclusion, of which 17 genomes from 6 studies were used for various in silico genetic analyses. Findings from this systematic review show that all mecC-carrying non-aureus staphylococci were resistant to only beta-lactam antibiotics and associated with the classical SCCmec XI of S. aureus LGA251. Similarly, two studies on wild animals reported mecC-carrying Mammaliicoccus stepanovicii associated with SCCmec XI. Nevertheless, most of the mecC-carrying Mammaliicoccus species presented an MDR phenotype (including linezolid) and carried the SCCmec-mecC hybrid associated with mecA. The phylogenetic analysis of the 17 genomes revealed close relatedness (<20 SNPs) and potential transmission of M. sciuri and M. lentus strains in livestock farms in Algeria, Tunisia, and Brazil. Furthermore, closely related M. sciuri strains from Austria, Brazil, and Tunisia (<40 SNPs) were identified. This systematic review enhances our comprehension of the epidemiology and genetic organization of mecC within the non-aureus staphylococci and mammaliicocci. It could be hypothesized that the mecC-carrying non-aureus staphylococci are evolutionarily related to the wild MRSA-mecC. The potential implications of clonal development of a lineage of mecA/mecC carrying strains across multiple dairy farms in a vast geographical region with the dissemination of MDR phenotype is envisaged. It was observed that most mecC-carrying non-aureus staphylococci and mammaliicocci were reported in mastitis cases. Therefore, veterinarians and veterinary microbiology laboratories must remain vigilant regarding the potential existence of mecA/mecC strains originating from mastitis as a potential niche for this resistance trait. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the epidemiology of infections-associated Staphylococcusaureus (S. aureus) from the Medical Intensive Care Unit (MICU) at University Hospital Center of Constantine (UHCC) in Algeria, with a special emphasis on methicillin-resistant strains (MRSA) revealed by cefoxitin disks (30 μg), then confirmed by penicillin-binding protein (PBP2a) agglutination and real-time polymerase chain reaction (RT-PCR) targeting mecA and mecC genes. Staphylococcal Cassette Chromosome mec (SCCmec type), staphylococcal protein A (spa-type), multilocus sequence type (MLST), Panton–Valentine Leucocidin (PVL), and toxic shock syndrome toxin-1 (TSST-1) were further investigated in all isolates, and whole genome sequencing was performed for a selected subset of three hospital-acquired MRSA (HA-MRSA) isolates. A measurement of 80% out of the 50 S. aureus isolates were identified as HA-MRSA harbouring the mecA gene, and 72.5% of them were multidrug resistant (MDR). Twelve STs, four different SCCmec cassettes, fourteen spa types, ten isolates Panton–Valentine Leukocidin (PVL)-positive, and three isolates TSST-1 were identified. Interestingly, there was a high prevalence (n = 29; 72.5%) of a worrisome emerging clone: the HA-MRSA ST239/241 SCCmec-III mercury with PVL negative, resistant to β-lactams, aminoglycosides, quinolones, and tetracyclines. Other clones of HA-MRSA isolates were also identified, including PVL-positive ST80 SCCmec-IV/SCCmec-unknown (22.5%), ST34 SCCmec-V with TSST-1 positive (2.5%), and PVL-negative ST72 SCCmec-II (2.5%). Genome analysis enables us to describe the first detection of both PVL-negative HA-MRSA ST239/241 SCCmec-III mercury carrying ccrC, as well as SCCmec-V cassette, which dramatically changes the epidemiology of S. aureus infections in one of the hospitals in eastern Algeria. [ABSTRACT FROM AUTHOR]

In this study, the phytochemical screening of lichen samples of Evernia prunastri collected from three different regions of Algeria (Jijel sample (JS), Setif sample (SS) and M’sila sample (MS)) was investigated. The phenolic and flavonoid contents of lichen extracts obtained by maceration in methanol were determined. The antioxidant activities of these extracts were measured by determining the total antioxidant capacity (TAC), the ferric reducing antioxidant power (FRAP) and the free radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Similarly, antibacterial activity was determined by solid medium diffusion and liquid medium microdilution methods against Gram-positive and Gram-negative bacteria. The qualitative phytochemical analysis of lichen samples revealed the presence of some compounds such as saponins, flavonoids, alkaloids. For quantitative analysis, the MS methanolic extract from M'Sila region showed the highest values for phenolic and flavonoid compounds which are equal to 929.3 mg/100g and 56.34 mg/100g, respectively. This extract also shows the best antioxidant activities with the three tested methods. For antibacterial activity, the best effect was obtained for the methanolic extract from Jijel region (JS) against the methicillin resistant Staphylococcus aureus strain with an inhibition zone of 35.33 mm and an MIC of 0.058 mg/mL. However, the three Evernia prunastri methanolic extracts (JS, SS and MS) were found to be inactive against Gram-negative bacteria. The obtained results indicate that the studied extracts have interesting antioxidant and antibacterial activities, which is probably due to the presence of phenolic and flavonoid compounds. [ABSTRACT FROM AUTHOR]

The emergence of resistant strains of Staphylococcus aureus is a major public health problem mainly in hospitals around the world and in Algeria in particular. This work aims to assess the resistance of Staphylococcus aureus in the University Hospital Center of Batna and the Hematology Unit of the Anti-Cancer Center using conventional standardized methods during a study period of four months. A total of 70 strains of S. aureus were isolated and their antibiotic susceptibility study showed significant resistance to β-lactam especially to penicillin (95.71%) and 61.43% to tobramycin. The methicillin-resistant strains (MRSA) formed 30%. Resistant strains to macrolide-lincosamide streptogramin B (MLSB) and aminoglycosides (KTG) classes presented 17.14% and 21.43% respectively. These results require a control plan by compliance with the hygiene conditions and the organization of the prescription of antibiotics and other molecular and epidemiological studies. [ABSTRACT FROM AUTHOR]

• Saturated sodium bentonite material was intercalated with amoxicillin. • The intercalation reaction takes place through an ion exchange process. • New hybrid materials amoxicillin loaded bentonite was elaborated. • The hybrid materials displayed a high antibacterial activity. • These materials can be used as DDS and reused several times. In this paper, natural bentonite (N-BENT) from the west of Algeria was used to prepare new inorganic-organic hybrid materials by accommodating amoxicillin (AMO) as a biological molecule in its interlayer space. The incorporation of AMO within the structure of bentonite was carried out through an ion exchange process between the interlayer's sodium and potassium cations, and the biological AMO molecules leading to two hybrids AMO1@BENT and AMO2@BENT materials with different AMO exchange rates. The intercalation of AMO between the aluminosilicate layers of bentonite material was confirmed by X-ray diffraction (XRD) analysis which showed that the basal spacing of bentonite shifted from 12.39 Å to ∼15 Å for both obtained hybrid materials. Other characterization methods such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and UV–Visible (UV-Vis) spectroscopy validated the intercalation of AMO in the bentonite and explained the phenomenon occurred during this intercalation process. The prepared materials were tested against gram-positive which are Bacillus subtilis (B. subtilis), Bacillus cereus (B. cereus) and Methicillin-resistant staphylococcus aureus (MRSA) and the gram-negative bacteria which are Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Klebsiella pneumoniae (K. pneumoniae), the results exhibited a very high antibacterial activity against the six bacteria. Indeed, an inhibition diameter as high as 55mm was obtained in the case of pathogenic MRSA bacteria. Furthermore, AMO2@BENT material is still very active against pathogenic MRSA bacteria after several reuses. All these results could make these low-cost hybrid materials exploitable in many different fields such as medicine, biology and the environment. Graphical abstract. [Display omitted]. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is a pathogenic microorganism of humans and animals, able to cause foodborne intoxication due to the production of staphylococcal enterotoxins (SEs) and to resist antibiotic treatment as in the case of methicillin-resistant S. aureus (MRSA). In this study, we performed a genomic characterisation of 12 genetically diverse S. aureus strains isolated from ready-to-eat foods in Algiers (Algeria). Moreover, their ability to produce some classical and new staphylococcal enterotoxins (SEs) was investigated. The 12 S. aureus strains resulted to belong to nine known sequence types (STs) and to the novel ST7199 and ST7200. Furthermore, S. aureus SA46 was assigned to the European clone MRSA-ST80-SCCmec-IV. The 12 strains showed a wide endowment of se and sel (staphylococcal enterotoxin-like toxin) genes (sea, seb, sed, seg, seh, sei, selj, sek, sem, sen, seo, seq, ser, selu2, selw, selx, sey, sel30; ψent1-ψent2), including variants and pseudogenes, and harboured the enterotoxin gene cluster (egc) types 1 and 5. Additionally, they produced various amounts of SEA (64.54–345.02 ng/mL), SEB (2871.28–14739.17 ng/mL), SED (322.70–398.94 ng/mL), SEH (not detectable–239.48 ng/mL), and SER (36,720.10–63,176.06 ng/mL) depending on their genotypes. The genetic determinants related to their phenotypic resistance to β-lactams (blaZ, mecA), ofloxacin (gyrA-S84L), erythromycin (ermB), lincomycin (lmrS), kanamycin (aph(3′)-III, ant(6)-I), and tetracyclin (tet(L), tet(38)) were also detected. A plethora of virulence-related genes, including major virulence genes such as the tst gene, determinant for the toxic shock syndrome toxin-1, and the lukF-PV and lukS-PV genes, encoding the panton-valentine leukocidin (PVL), were present in the S. aureus strains, highlighting their pathogenic potential. Furthermore, a phylogenomic reconstruction including worldwide foodborne S. aureus showed a clear clustering based on ST and geographical origin rather than the source of isolation. [ABSTRACT FROM AUTHOR]

Polianthes tuberosa L. (Amaryllidaceae) is an ornamental and medicinal plant. Its flowers and bulbs are used traditionally as a diuretic, emetic, against rashes and gonorrhea. The aim of this work was, to evaluate the antioxidant and antimicrobial activities of bulbs and bulbils alkaloid extracts of P. tuberosa. Antiradical effect was assessed against DPPH radical. However, antimicrobial activity was measured through the disc diffusion method against Escherichae coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Staphylococcus aureus resistant to Methicillin (MRSA) and Candida albicans ATCC 90028. The scavenging effect against DPPH showed that the bulbs and bulbils alkaloids extracts exhibited an antiradical effect with IC50 = 0.231±0.017 mg/mL and 0.233±0.093 mg/mL respectively, less than the effect of vitamin C with IC50 = 0.0194±0.0002 mg/mL. Antimicrobial activity results reveal that both alkaloid bulbs extracts at 50 mg/mL did not have any inhibitory effect against the studied strains using the disc diffusion method. According to this work, bulbs and bulbils alkaloid extracts show a moderate antioxidant effect; that could be recommended as a natural antioxidant. Although tuberose bulbs were used traditionally as a soap substitute; bulbs alkaloid extract has no antimicrobial effect. [ABSTRACT FROM AUTHOR]