Deciphering the geochemical influences on bacterial diversity and communities among two Algerian hot springs.

Northeastern Algeria boasts numerous hot springs, yet these hydrothermal sites remain largely unexplored for their microbial ecology. The present study explores the bacterial abundance and diversity within two distinct Algerian hot springs (Hammam Saïda and Hammam Debagh) and investigates the link between the prevailing bacteria with geochemical parameters. High-throughput 16S rRNA gene sequencing of water and sediment samples revealed a bacterial dominance of 99.85-91.16% compared to Archaea (0.14-0.66%) in both springs. Interestingly, Saïda hot spring, characterized by higher temperatures and sodium content, harbored a community dominated by Pseudomonadota (51.13%), whereas Debagh, a Ca-Cl-SO4 type spring, was primarily populated by Bacillota with 55.33%. Bacteroidota displayed even distribution across both sites. Additional phyla, including Chloroflexota, Deinococcota, Cyanobacteriota, and Chlorobiota, were also present. Environmental factors, particularly temperature, sodium, potassium, and alkalinity, significantly influenced bacterial diversity and composition. These findings shed light on the interplay between distinct microbial communities and their associated geochemical properties, providing valuable insights for future research on biogeochemical processes in these unique ecosystems driven by distinct environmental conditions, including potential applications in bioremediation and enzyme discovery.

MALDI-TOF mass spectrometry identification and antifungal susceptibility testing of yeasts causing vulvovaginal candidiasis (VVC) in Tebessa (Northeastern Algeria).

Vulvovaginal candidiasis (VVC) alongside with antifungal resistance are becoming a major clinical problem in recent years. A prospective study aimed to evaluate the diversity of yeast strains associated with VVC in Tebessa city (northeastern Algeria) and investigate their susceptibility patterns. Over two months, yeasts were isolated on chromogenic medium from twenty-nine non-pregnant women with symptomatic VVC. The isolates were characterized with MALDI-TOF MS and antifungal susceptibility testing was performed for nine antifungal drugs using SensititreTM YeastOneTM YO10. Twenty-nine non-duplicate yeasts were recovered and the mass spectrometry profiles showed reliable scores of which four genera and five different species were identified. Candida albicans accounted for 65.5 % (n = 19) of the total number of isolates, followed by C. glabrata with 20.7% (n = 6). For the remaining non-albicans Candida (NCA) species, Kluyveromyces marxianus with 6.9% (n = 2), Pichia kudriavzevii and Saccharomyces cerevisiae with one isolate each. The antifungal susceptibilities showed wild type MICs of C. albicans to amphotericin B, azoles and echinocandins. In addition, four C. albicans isolates were resistant to flucytosine. For C. glabrata isolates, 100% non-WT phenotype was found for both posaconazole and itraconazole. For the very first time, the obtained outcomes bring out new data concerning the epidemiology of yeasts causing VVC in Algeria and their antimicrobial susceptibility profiles.

Unraveling the enzymatic and antibacterial potential of rare halophilic actinomycetes from Algerian hypersaline wetland ecosystems.

The study aimed to isolate rare halophilic actinomycetes from hypersaline soils of Algerian inland Wetland Ecosystems "Sebkhas-Chotts" located in arid and hot hyperarid lands with international importance under the Ramsar Convention and to explore their enzyme-producing and antibacterial abilities. The halophilic actinomycetes were selectively isolated using agar-rich media supplemented with 5, 10, and 15% (W/V) of total salts. Thirty-one isolates were obtained and 16S rRNA gene sequencing analysis revealed the presence of members affiliated to rare halophilic actinobacterial genera (Actinopolyspora and Nocardiopsis) accounting for 74.19% (23 isolates out of 31) and 25.8% (8 isolates), respectively. Both phylotypes are alkalitolerant and halophilic thermotolerant actinomycetes displaying significant hydrolytic activities relative to (amylase, asparaginase, cellulase, esterase, glutaminase, inulinase, protease, pectinase, xylanase), and over 96% of tested isolates exhibited all common enzymes, mainly active at 10% of growing salt. In addition, high antibacterial activity was observed against Bacillus cereus, Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus. The findings showed that saline wetlands ecosystems represent a rich reservoir for the isolation of significant rare halophilic actinomycetes with potential adaptive features and valuable sources for novel bioactive metabolites and biocatalysts of biotechnological interest.

Genomic Diversity of SARS-CoV-2 in Algeria and North African Countries: What We Know So Far and What We Expect?

Here, we report a first comprehensive genomic analysis of SARS-CoV-2 variants circulating in North African countries, including Algeria, Egypt, Libya, Morocco, Sudan and Tunisia, with respect to genomic clades and mutational patterns. As of December 2021, a total of 1669 high-coverage whole-genome sequences submitted to EpiCoV GISAID database were analyzed to infer clades and mutation annotation compared with the wild-type variant Wuhan-Hu-1. Phylogenetic analysis of SARS-CoV-2 genomes revealed the existence of eleven GISAID clades with GR (variant of the spike protein S-D614G and nucleocapsid protein N-G204R), GH (variant of the ORF3a coding protein ORF3a-Q57H) and GK (variant S-T478K) being the most common with 25.9%, 19.9%, and 19.6%, respectively, followed by their parent clade G (variant S-D614G) (10.3%). Lower prevalence was noted for GRY (variant S-N501Y) (5.1%), S (variant ORF8-L84S) (3.1%) and GV (variant of the ORF3a coding protein NS3-G251V) (2.0%). Interestingly, 1.5% of total genomes were assigned as GRA (Omicron), the newly emerged clade. Across the North African countries, 108 SARS-CoV-2 lineages using the Pangolin assignment were identified, whereby most genomes fell within six major lineages and variants of concern (VOC) including B.1, the Delta variants (AY.X, B.1.617.2), C.36, B.1.1.7 and B.1.1. The effect of mutations in SAR-CoV-2 genomes highlighted similar profiles with D614G spike (S) and ORF1b-P314L variants as the most changes found in 95.3% and 87.9% of total sequences, respectively. In addition, mutations affecting other viral proteins appeared frequently including; N:RG203KR, N:G212V, NSP3:T428I, ORF3a:Q57H, S:N501Y, M:I82T and E:V5F. These findings highlight the importance of genomic surveillance for understanding the SARS-CoV-2 genetic diversity and its spread patterns, leading to a better guiding of public health intervention measures. The know-how analysis of the present work could be implemented worldwide in order to overcome this health crisis through harmonized approaches.

Broad-spectrum antimicrobial activity of wetland-derived Streptomyces sp. ActiF450.

The increased incidence of invasive infections and the emerging problem of drug resistance particularly for commonly used molecules have prompted investigations for new, safe and more effective microbial agents. Actinomycetes from unexplored habitats appear as a promising source for novel bioactive compounds with a broad range of biological activities. Thus, the present study aimed to isolate effective wetland-derived actinomycetes against major pathogenic fungi and bacteria. Water samples were collected from various locations of Fetzara Lake, Algeria. Thereafter, an actinomycete designated ActiF450 was isolated using starch-casein-agar medium. The antimicrobial potential of the newly isolated actinomycete was screened using the conventional agar cylinders method on Potato Dextrose Agar (PDA) against various fungal and bacterial pathogens. A wetland-derived Streptomyces sp. Actif450 was identified as Streptomyces malaysiensis based on its physiological properties, morphological characteristics, and 16S rDNA gene sequence analysis. The antimicrobial activity of Streptomyces sp. ActiF450 showed a potent and broad spectrum activity against a range of human fungal pathogens including moulds and yeasts, such as Arthroderma vanbreuseghemii, Aspergillus fumigatus, A. niger, Candida albicans, C. glabarta, C. krusei, C. parapsilosis, Fusarium oxysporum, F. solani, Microsporum canis, Rhodotorula mucilaginous and Scodapulariopsis candida. In addition, high antibacterial activity was recorded against pathogenic staphylococci. The novel Streptomyces sp. ActiF450 may present a promising candidate for the production of new bioactive compounds with broad-spectrum antimicrobial activity.

Culturable halophilic bacteria inhabiting Algerian saline ecosystems: A source of promising features and potentialities.

This paper aims to characterize halophilic bacteria inhabiting Algerian Saline Ecosystems (Sebkha and Chott) located in arid and semi-arid ecoclimate zones (Northeastern Algeria). In addition, screening of enzymatic activities, heavy metal tolerance and antagonistic potential against phytopathogenic fungi were tested. A total of 74 bacterial isolates were screened and phylogenetically characterized using 16S rRNA gene sequencing. The results showed a heterogeneous group of microorganisms falling within two major phyla, 52 strains belonging to Firmicutes (70.2%) and 22 strains (30.8%) of γ-Proteobacteria. In terms of main genera present, the isolates were belonging to Bacillus, Halobacillus, Lentibacillus, Oceanobacillus, Paraliobacillus, Planomicrobium, Salicola, Terribacillus, Thalassobacillus, Salibacterium, Salinicoccus, Virgibacillus, Halomonas, Halovibrio, and Idiomarina. Most of the enzymes producers were related to Bacillus, Halobacillus, and Virgibacillus genera and mainly active at 10% of growing salt concentrations. Furthermore, amylase, esterase, gelatinase, and nuclease activities ranked in the first place within the common hydrolytic enzymes. Overall, the isolates showed high minimal inhibitory concentration values (MIC) for Ni2+ and Cu2+ (0.625 to 5 mM) compared to Cd2+ (0.1 to 2 mM) and Zn2+ (0.156 to 2 mM). Moreover, ten isolated strains belonging to Bacillus, Virgibacillus and Halomonas genera, displayed high activity against the pathogenic fungi (Botrytis cinerea, Fusarium oxyporum, F. verticillioides and Phytophthora capsici). This study on halophilic bacteria of unexplored saline niches provides potential sources of biocatalysts and novel bioactive metabolites as well as promising candidates of biocontrol agents and eco-friendly tools for heavy metal bioremediation.

Occurrence of VIM-4 metallo-ß-lactamase-producing Pseudomonas aeruginosa in an Algerian hospital.

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-ß-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.

Phenotypic characterization of rhizobia nodulating legumes Genista microcephala and Argyrolobium uniflorum growing under arid conditions.

A phenotypic characterization of thirteen root nodule bacteria recovered from wild legumes (Genista microcephala and Argyrolobium uniflorum) growing in arid eco-climate zones (Northeastern Algeria) was conducted using analysis of sixty-six phenotypic traits (carbohydrate and nitrogen assimilation, vitamin requirements, growth temperature, salinity/pH tolerance and enzyme production). Furthermore, SDS-PAGE profiles of total cell protein, antibiotic susceptibility and heavy metal resistance were performed. The results showed that the isolates can grow at pH 4 to 10, salt concentration (0-5%) and temperature up to 45 °C. The rhizobia associated with Genista microcephala and Argyrolobium uniflorum were able to produce different hydrolytic enzymes including cellulose, pectinase and urease, with remarkable tolerance to toxic metals such as zinc, lead, copper, and mercury. Numerical analysis of the phenotypic characteristics revealed that the rhizobial isolates formed four main distinct groups showing high levels of similarity with Gammaproteobacteria. The salt tolerant and heavy metals resistance patterns found among the indigenous rhizobial strains are reflecting the environmental stresses pressure and make the strains good candidates for plant successful inoculation in arid areas.

Diversity and bioprospecting of extremely halophilic archaea isolated from Algerian arid and semi-arid wetland ecosystems for halophilic-active hydrolytic enzymes.

The diversity of haloarchaea associated with different dry salt lakes in northeastern Algeria was investigated together with their potential of hydrolytic enzyme production. A total of 68 aerobic halophilic archaea were isolated from saline sediments. Based on the 16S rRNA gene sequencing, the isolates were assigned to seven phylotypes within the class Halobacteria, namely Haloarcula, Halococcus, Haloferax, Halogeometricum, Haloterrigena, Natrialba, and Natrinema. The results showed that Haloferax group was found to be dominant in all samples (30 isolates) (44%) with high diversity, followed by Halococcus spp. (13%) (9 isolates). All phylotypes are extreme halophiles and thermotolerant with the ability to grow at temperatures up to 48 °C. In addition, the screening for extracellular halophilic enzymes showed that 89.7% of the isolates were able to produce at least two types of the screened enzymes. The strains producing esterase, gelatinase, inulinase, cellulase and protease activities were the most diverse functional group. These data showed an abundant and diverse haloarchaeal community, detected in Algerian wetland ecosystems, presenting a promising source of molecules with important biotechnological applications.

Modeling the synergistic antibacterial effects of honey characteristics of different botanical origins from the Sahara Desert of Algeria.

BACKGROUND: Honey has multiple therapeutic properties due to its composition with diverse components. OBJECTIVES: This study aims to investigate the antimicrobial efficacy of Saharan honeys against bacterial pathogens, the variation of honey floral origins, and its physicochemical characteristics. MATERIALS AND METHODS: The antimicrobial activity of 32 samples of honey collected from the Algerian Sahara Desert was tested on four bacteria; Bacillus subtilis, Clostridium perfringens, Escherichia coli, and Staphylococcus aureus. The botanical origin of honeys and their physicochemical properties were determined and their combined antibacterial effects were modeled using a generalized linear mixed model (GLMM). RESULTS: Out of the 32 study samples, 14 were monofloral and 18 were multifloral. The pollen density was on average 7.86 × 10(6) grains/10 g of honey, water content was 14.6%, electrical conductivity (EC) was 0.5 µS/cm, pH was 4.38 ± 0 50, hydroxymethylfurfural (HMF) content was 82 mg/kg of honey, total sugars = 83%, reducing sugars = 71%, and the concentration of proline = 525.5 ± 550.2 mg/kg of honey. GLMM revealed that the antibacterial effect of honey varied significantly between bacteria and floral origins. This effect increased with increasing of water content and reducing sugars in honey, but it significantly decreased with increase of honey EC. E. coli was the most sensitive species with an inhibition zone of 10.1 ± 4.7 mm, while C. perfringens was the less sensitive. Honeys dominated by pollen of Fabaceae sp. were most effective with an overall antimicrobial activity equals to 13.5 ± 4.7 mm. CONCLUSION: Saharan honeys, of certain botanical origins, have physicochemical and pollinic characteristics with relevant potential for antibacterial purposes. This encourages a more comprehensive characterization of honeys with in vivo and in vitro investigations.

External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis.

A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches (Blattella germanica and Blatta orientalis) collected from households in Tebessa (northeast Algeria). Three major bacterial groups were cultured (total aerobic, enterobacteria, and staphylococci) from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable (P<0.001) and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of (2.1 × 105 CFU/insect), whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.

Spatiotemporal diversity, structure and trophic guilds of insect assemblages in a semi-arid Sabkha ecosystem.

The current study highlights some knowledge on the diversity and structure of insect communities and trophic groups living in Sabkha Djendli (semi-arid area of Northeastern Algeria). The entomofauna was monthly sampled from March to November 2006 using pitfall traps at eight sites located at the vicinity of the Sabkha. Structural and diversity parameters (species richness, Shannon index, evenness) were measured for both insect orders and trophic guilds. The canonical correspondence analysis (CCA) was applied to determine how vegetation parameters (species richness and cover) influence spatial and seasonal fluctuations of insect assemblages. The catches totalled 434 insect individuals classified into 75 species, 62 genera, 31 families and 7 orders, of which Coleoptera and Hymenoptera were the most abundant and constant over seasons and study stations. Spring and autumn presented the highest values of diversity parameters. Individual-based Chao-1 species richness estimator indicated 126 species for the total individuals captured in the Sabkha. Based on catch abundances, the structure of functional trophic groups was predators (37.3%), saprophages (26.7%), phytophages (20.5%), polyphages (10.8%), coprophages (4.6%); whereas in terms of numbers of species, they can be classified as phytophages (40%), predators (25.3%), polyphages (13.3%), saprophages (12%), coprophages (9.3%). The CCA demonstrated that phytophages and saprophages as well as Coleoptera and Orthoptera were positively correlated with the two parameters of vegetation, especially in spring and summer. While the abundance of coprophages was positively correlated with species richness of plants, polyphage density was positively associated with vegetation cover. The insect community showed high taxonomic and functional diversity that is closely related to diversity and vegetation cover in different stations of the wetland and seasons.

Bacterial load of German cockroach (Blattella germanica) found in hospital environment.

BACKGROUND: Cockroaches are among the most common pests in public dwellings and health facilities. Their presence can raise safety concerns, especially as they maybe carriers of pathogenic organisms. METHODS: This study was carried out to isolate and identify the bacterial flora from German cockroaches (Blattella germanica). Cockroaches collected by hand catches from two public hospital environments in Tebessa city (northeast Algeria) were screened for microbial load from their external surfaces and alimentary tract using standard bacterial protocols. RESULTS: A total of 174 bacterial isolates were isolated from 39 German cockroach specimens. The most common and abundant bacterial species belonged to the Pseudomonas group (23.5%) and Serratia (13.2%). Pathogens like Staphylococcus aureus were also isolated, as well as opportunistic pathogens like Klebsiella species and food spoilage bacteria such as Enterobacter and Citrobacter species were isolated from both external surface and digestive tract of the insect. Generalized linear models (GLM) were performed to analyze the variation of abundances and occurrences of bacterial isolates harboured by B. germanica. The GLMs revealed that the main factors affecting variation of bacterial diversity and abundance were sex and hospital (P < 0.001). CONCLUSION: The findings of this study suggest that German cockroach acts as reservoir and potential vector of some bacterial pathogens.