Genospecies and virulence factors of Aeromonas species in different sources in a North African country

Introduction: Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few.Methods: In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], nondiarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28]) in Tripoli, Libya, were included in the present investigation. Genus identification was confirmed by biochemical analysis, and genospecies were determined using a combination of 16S rDNA variable region and gyrB sequence analysis. Polymerase chain reaction (PCR) was used to detect genes encoding toxins from 52 of the isolates.Results: We identified 44 isolates (44%) as A. hydrophila (3 [3.0%] subspecies anaerogenes, 23 [23%] subspecies dhakensis, and 18 [18%] subspecies ranae); 27 isolates (27%) as A. veronii; 23 isolates (23%) as A. caviae; and 5 isolates (5.0%) as other genospecies. The genes encoding aerolysin (aer), cytolytic enterotoxin (act), and A. hydrophila isolate SSU enterotoxin (ast) were detected in 45 (87%), 4 (7.7%), and 9 (17%) of the 52 isolates tested, respectively. The gene encoding an extracellular lipase (alt) was not detected.Conclusion: The majority of aeromonads from Libya fall within three genospecies (i.e. A. hydrophila, A. veronii, and A. caviae), and genes coding for toxin production are common among them.Keywords: Aeromonas; genospecies; virulence factors; Liby

Biological activities of essential oils from leaves of paramignya trimera (Oliv.) guillaum and limnocitrus littoralis (miq.) swingle

The present study aimed to determine the bioactivities of essential oils extracted from the leaves of Paramignya trimera and Limnocitrus littoralis, including cytotoxicity, antiviral, antibacterial, antimycotic, and antitrichomonas effects. Herein, it was indicated that P. trimera and L. littoralis oils showed no cytotoxicity on normal cells, namely MT-4, BHK-21, MDBK, and Vero-76. P. trimera oil (i) exhibited the strongest inhibition against Staphylococcus aureus with MIC and MLC values of 2% (v/v); (ii) showed MIC and MLC values of 8% (v/v) in Candida parapsilosis; and (iii) in the remaining strains, showed MIC and MLC values greater than or equal to 16% (v/v). On the other hand, L. littoralis oil (i) displayed the strongest inhibition against Candida tropicalis and Candida parapsilosis with 2% (v/v) of MIC and MLC; and (ii) in the remaining strains, possessed MIC and MLC greater than or equal to 16% (v/v). In addition, antitrichomonas activities of the oils were undertaken, showing IC50, IC90, MLC values, respectively, at 0.016%, 0.03%, and 0.06% (v/v) from P. trimera, and 0.03%, 0.06%, 0.12% (v/v) from L. littoralis, after 48 h of incubation. The oils were completely ineffective against ssRNA+ (HIV-1, YFV, BVDV, Sb-1, CV-B4), ssRNA- (RSV, VSV), dsRNA (Reo-1), and dsDNA (HSV-1, VV) viruses. This is the first report describing the cytotoxicity, antiviral, antibacterial, antimycotic, and antitrichomonas activities of the essential oils of P. trimera and L. littoralis

Extracellular release by Trichomonas vaginalis of a NADP+ dependent malic enzyme involved in pathogenicity

This report presents evidence showing that Trichomonas vaginalis releases in the extracellular environment a functional form of NADP+- dependent malic enzyme. The protein which is likely responsible for the oxidative decarboxilase activity had already been identified in previous studies as P65, one of the five adhesive proteins of the protozoan. The same protein had also been described as AP65 by other authors, which identified it as one of the four surface proteins specifically responsible for binding of the parasite to the target cell in a ligand-receptor fashion. Gene characterization studies performed on P65 by different authors revealed that the nucleotide sequences of the genes coding for P65 display a striking homology with the ones coding for the trichomonad malic enzyme. The experiments performed in this work demonstrate that P65 is secreted and retains its adhesive properties in the extracellular environment, being able to bind both erythrocytes and HeLa cells. Therefore, an oxidative decarboxylase activity assay was performed on T. vaginalis cell-free flitrates, in order to assess if the released P65 displays cathalitic properties. The assay revealed that parasite-free supernatants exhibit an oxidative decarboxylase activity which is NADP+-dependent. On the basis of the most recent findings on T. vaginalis pathogenetic mechanism, which involves pH-dependent perforins, a role for the secreted enzyme as part of the system is proposed

Wreckfish, Polyprion americanus (Bloch and Schneider 1801), a promising species for aquaculture: proximate composition, fatty acid profile and cholesterol content of wild Mediterranean specimens

The proximate composition and fatty acid profile of 62 wreckfish (Polyprion americanus) specimens caught in the northern marine area of the island of Sardinia in the Mediterranean Sea were determined. Over a 2-year period, fish were captured in 14 surveys and grouped according to body size, sex, and harvest. Two distinct sizes were collected at different water depths: the largest wreckfish (>16.5 kg, >65 cm) of both sexes were collected from deep waters (500–560 m); small individuals, with significantly lower body length and weight (4.5–11 kg) were found in shallower waters. The smallest groups had the lowest moisture content (73.19–73.81%), the greatest amount of protein (20.42–20.60%) and the highest lipid level (4.04–4.36%) compared to other groups. The three groups of the smaller sized wreckfish had the high proportion of 18:1 (27–27.9%). DHA was dominant in 11 of the wreckfish survey groups, representing 24.2–25.7% of total fatty acids. Findings could potentially be applied to optimize feeding husbandry protocols of fish farming practices in aquaculture. Data obtained here could be used to elucidate the nutritional traits that characterize meat quality of wreckfish, which are becoming increasingly important considerations of consumers and human health specialists

Trichomonas vaginalis resistance to Mengo virus infection

We have investigated the susceptibility of Trichomonas vaginalis to Mengo virus infection by comparing the outcome of Mengo virus or purified Mengo virus RNA infection in T. vaginalis and in CCL-1 mouse fibroblasts. While the adsorption and entry of Mengo virus into T. vaginalis occurred in the same manner as in fibroblasts, the uncoating was much slower. In addition, Mengo virus infection of T. vaginalis displayed no eclipse nor any subsequent production of infectious virus. Purified RNA failed to initiate productive infection in T. vaginalis, whereas it provoked viral replication in the fibroblast controls. It was shown by assessment of protein synthesis in T. vaginalis and mouse fibroblasts cell-free systems that the protozoan ribosomes were able to translate endogenous mRNA and poly-U, but not viral RNA