Evolution of copper coupons resistance in Enterobacteriaceae strains isolated from high-contact surfaces in hospital.

Objective: Metallic copper alloys have gained attention recently as a cutting-edge antibacterial weapon for areas where surface hygiene is crucial. The present study aimed to assess copper coupons (99% Cu) for their potential to decrease the viability of various Enterobacteriaceae strains from inanimate hospital surfaces. Methods: This in vitro-experimental study was conducted at the Microbiology Laboratory, Faculty of Natural and Life Sciences and Earth and Universe Sciences, University of Guelma, and Khodja Ahmed Public Hospital Establishment, Algeria, for a period of six months from January to May 2022. A total of 85 samples were collected from patient room door handles and bed rails at the government hospital in Guelma State, from which 12 enterobacterial isolates were obtained. These isolates were evaluated for susceptibility to copper and polyvinyl chloride (PVC) coupons using plate counts to determine bacterial viability after 72 hours of incubation at 37°C or room temperature (25°C). Antibiotic sensitivity testing was then carried out using a modified Kirby-Bauer disc diffusion method. Copper coupons' ability to either select for or create antibiotic resistance is also determined. Results: Copper showed a bactericidal effect after three hours for Serratia odorifera and six hours for Escherichia coli. Whereas it was shown that within three days of selection, 83.33% of Enterobacteriaceae strains are capable of rapidly acquiring Cu resistance. Indeed, the increase in temperature reduced the effects of Cu (p<0.05; Student's t-test). Antimicrobial susceptibility testing revealed that the copper-resistant bacteria were less sensitive than their predecessors. Citrobacter freundii strains showed the highest incidence of multidrug resistance. The most significant findings included widespread resistance to beta-lactams (100%-75%) and chloramphenicol (66.67%). Conclusion: These results suggest that prolonged copper usage may contribute to the development of antibiotic resistance, which could have significant ramifications.

First evidence of plastic pollution in beach sediments of the Skikda coast (northeast of Algeria).

This study is the first attempt to provide original data on plastics debris occurrence in beach sediments of the Gulf of Skikda in Algeria (southwestern Mediterranean). Sediment samples from seven beaches were collected to extract, quantify and characterize mesoplastics and microplastics. Particles were classified by size into mesoplastics (5-25 mm) and large microplastics (1-5 mm). Overall, microplastics were the most abundant size fraction in terms of number of items. The average mass of mesoplastics was twice that of microplastics, revealing a notable reservoir of plastics that is scarcely ever reported in the literature. The predominant types were fragments and pellets, white/transparent in color. The average concentrations of total plastic were 1067.19 ± 625.62 items/m2, 106.98 ± 62.39 items/kg, and 50.65 ± 9.82 g/m2, showing variability between beaches and within sampling sites. Thus, the Skikda coast has high levels of pollution compared to other areas of the Mediterranean Sea.

Occurrence and distribution of fecal indicators and pathogenic bacteria in seawater and Perna perna mussel in the Gulf of Annaba (Southern Mediterranean).

The identification of fecal contamination in coastal marine ecosystems is one of the main requirements for evaluation of potential risks to human health. The objective of this study was to investigate the occurrence and distribution of fecal indicators and pathogenic bacteria in seawaters and mussels collected monthly during a period of 1 year from four different sites in Northeastern Algeria (sites S1 to S4), through biochemical and molecular analyses. Our research is the first to use molecular analysis to unambiguously identify the potentially pathogenic bacteria present in Algerian Perna perna mussels. The obtained results revealed that the levels of fecal indicator bacteria (FIB) from both P. perna and seawater samples largely exceeded the permissible limits at S2 and S3. This is mainly related to their location close to industrial and coastal activity zones, which contain a mixture of urban, agricultural, and industrial pollutants. Besides, P. perna collected from all sites were severalfold more contaminated by FIB than seawater samples, primarily during the warm season of the study period. Biochemical and molecular analyses showed that isolated bacteria from both seawater and mussels were mainly potentially pathogenic species such as E. coli, Salmonella spp., Staphylococcus spp., Klebsiella spp., Pseudomonas spp., and Proteus spp.

Complete Genome Sequence of Microbacterium sp. Strain Nx66, Isolated from Waters Contaminated with Petrochemicals in El Saf-Saf Valley, Algeria.

Microbacterium sp. strain Nx66 was isolated from waters contaminated by petrochemical effluents collected in Algeria. Its genome was sequenced using Illumina MiSeq (2 × 150-bp read pairs) and Oxford Nanopore (long reads) technologies and was assembled using Unicycler. It is composed of one chromosome of 3.42 Mb and one plasmid of 34.22 kb.

Antibacterial effect of copper sulfate against multi-drug resistant nosocomial pathogens isolated from clinical samples.

BACKGROUND AND OBJECTIVE: With the emergence of antibiotic resistance and the hospital acquired infection, the interest for antimicrobial agents has recently increased again in public health. Copper is recommended as a supplementary method of increasing biological safety in the hospital environment. The objective of this study was to determine the antibacterial activity of copper sulfate salts on strains of bacterial pathogens isolated from different clinical pictures in different health establishment in Algeria. METHODS: A total of 25 different bacterial isolates (16 Enterobacteriaceae, 5 Staphylococci, and 4 Pseudomonas) were tested for susceptibility to copper sulfate using minimum inhibitory concentration (MIC-Cu) and minimum bactericidal concentrations (MBC-Cu) determinations. All isolates were also tested for susceptibility to six antibiotics. RESULTS: Antibiotic susceptibility studies revealed that 100% of isolates were resistant to one or more antibiotics. Fifty two percent of isolates were very susceptible to copper sulfate, with MICs ranging from 100 to 200 µg/ml. MBC-Cu = 1600 µg/ml showed the best bactericidal effect against the great majority of studied bacteria (52%). A good bactericidal activities of copper sulfate were recorded against Proteus vulgaris and Staphylococcus aureus (MBC/MIC=1). The Gram-negative bacteria isolates which were copper resistant also showed a high resistance to chloramphenicol (r=0.78) and Trimethoprime (r=0.61). Furthermore, the strains that were no-susceptible to three different antimicrobial classes (Escherichia coli, Staphylococcus saprophyticus) were not resistant to copper sulfate. CONCLUSION: Copper sulfate salts has significant antibacterial activity against multi-drug resistant nosocomial pathogens.

Unusual cohabitation and competition between Planktothrix rubescens and Microcystis sp. (cyanobacteria) in a subtropical reservoir (Hammam Debagh) located in Algeria.

Succession in bloom-forming cyanobacteria belonging to distant functional groups in freshwater ecosystems is currently an undescribed phenomenon. However in the Hammam Debagh reservoir (Algeria), P. rubescens and Microcystis sp. co-occur and sometimes proliferate. With the aim of identifying the main factors and processes involved in this unusual cohabitation, water samples were collected monthly from February 2013 to June 2015 at the subsurface at four sampling stations and along the entire water column at one sampling station. In addition, the composition of the cyanobacterial communities was estimated by Illumina sequencing of a 16S rRNA gene fragment from samples collected over one year (October 2013-November 2014). This molecular approach showed that the Hammam Debagh reservoir displays high species richness (89 species) but very low diversity due to the high dominance of Microcystis in this community. Furthermore, it appears that Planktothrix rubescens and Microcystis sp. coexisted (from September to January) but proliferated alternately (Spring 2015 for P. rubescens and Spring 2014 and Autumn 2014/2015 for Microcystis). The main factors and processes explaining these changes in bloom-forming species seem to be related to the variation in the depth of the lake during the mixing period and to the water temperatures during the winter prior to the bloom season in spring.

Management of toxic cyanobacteria for drinking water production of Ain Zada Dam.

Blooms of toxic cyanobacteria in Algerian reservoirs represent a potential health problem, mainly from drinking water that supplies the local population of Ain Zada (Bordj Bou Arreridj). The objective of this study is to monitor, detect, and identify the existence of cyanobacteria and microcystins during blooming times. Samples were taken in 2013 from eight stations. The results show that three potentially toxic cyanobacterial genera with the species Planktothrix agardhii were dominant. Cyanobacterial biomass, phycocyanin (PC) concentrations, and microcystin (MC) concentrations were high in the surface layer and at 14 m depth; these values were also high in the treated water. On 11 May 2013, MC concentrations were 6.3 µg/L in MC-LR equivalent in the drinking water. This study shows for the first time the presence of cyanotoxins in raw and treated waters, highlighting that regular monitoring of cyanobacteria and cyanotoxins must be undertaken to avoid potential health problems.

Larval electroreceptors in the epidermis of mormyrid fish: II. The promormyromast.

Promormyromasts were found in the epidermis of the head of the larvae of five species of mormyrids bred in captivity. The promormyromast is a larval electroreceptor belonging to the specific lateral line system. In 12-day-old larvae this electroreceptor is characterized by a single sensory cell and two types of accessory cells. One type of accessory cell has dark cytoplasm, few microtubules, and contacts the sensory cell directly, whereas a second type has pale cytoplasm, many microtubules, and forms an outer layer not directly in contact with the sensory cell. This second type is referred to as a long pyriform accessory cell. This assembly of cells is situated below an intraepidermal cavity filled with acid polysaccharides. The bordering epidermal cells extend microvilli into the intraepidermal cavity. The apexes of the sensory cell, and of the two types of accessory cells, also open into the intraepidermal cavity but bear no microvilli. The promormyromast is innervated by an unmyelinated sensory nerve fiber passing through the basal membrane, which then splits into several branches between the accessory cells. These branches contact the periphery of the sensory cell with terminal boutons. At the site of each contact a ribbon-like structure surrounded by vesicles is present in the cytoplasm of the sensory cell. In older larvae of Campylomormyrus cassaicus, membrane foldings develop at the periphery of the pyriform accessory cells and accessory cell staining properties change just before transformation to become a mormyromast. The functional role of the promormyromast of the larval mormyrids is discussed.

Larval electroreceptors in the epidermis of mormyrid fish: I. Tuberous organs of type A and B.

Two types of larval electroreceptors, type A and B, are described in the epidermis of the head of larvae of three mormyrid species, Campylomormyrus cassaicus, Mormyrus rume proboscirostris and Pollimyrus isidori, bred in captivity. In each of these electroreceptor organs, a single sensory cell is found inside an intraepidermal cavity, sitting on a platform of accessory cells. The cavity is filled with microvilli originating both from the sensory cell and from the epidermal covering cells lining the intraepidermal cavity. These two types of tuberous larval electroreceptors differ in their distribution in the epidermis of the head, in the composition of their accessory cells, and by their innervation. The innervation found in type B organs is similar to that already described for electroreceptors of adult mormyrids. The sensorineural junction is composed of primary afferent terminal boutons, which contact the base of the sensory cell. Opposite each terminal bouton, a ribbon-like synaptic bar surrounded by vesicles is found in the cytoplasm of the sensory cell. In contrast, the base of the sensory cell in type A larval electroreceptors is not contacted by nervous terminal boutons, but instead forms closed appositions with specialized prolongations of accessory cells of the platform. The base of the sensory cell presents membrane evaginations, with hemispheric synaptic structures and few synaptic vesicles. These two types of electroreceptor organs degenerate at the time of the degeneration of the larval electric organ and the functional differentiation of the adult electric organ. The functional role of two tuberous electroreceptor types is examined.