Common Species Research Articles

Bartonella rochalimae in a flea collected from a Mephitis macroura in Sonora Mexico.

At least thirty species of wild carnivores have been recorded harboring Bartonella, and one of the most common pathogenic species infecting them is Bartonella rochalimae, which can cause endocarditis in humans and dogs. This bacterium can infect various mammals including wild carnivores, as well as ectoparasitic vectors such as fleas and ticks. Here we report the presence of B. rochalimae, in a Pulex simulans flea collected from a Mephitis macroura skunk in the municipality of Santa Cruz in Sonora, Mexico. Fleas were collected from a M. macroura in Sonora, Mexico, in October 2019. They were identified to species level and subsequently tested for the presence of Bartonella using molecular tools including conventional PCR, sequencing, and phylogenetic analysis. A total of 10 P. simulans fleas (one male, nine females) were collected from the M. macroura skunk. The PCR and phylogenetic analysis indicated a prevalence of 10% (1/10) and a sequence clustered with the clade of B. rochalimae. We confirmed the presence of B. rochalimae in a P. simulans flea collected from a M. macroura skunk in the area of Santa Cruz, Sonora, Mexico. Based on our results and previous studies in northern Mexico, which are consistent, it is necessary to continue monitoring Bartonella in M. macroura skunks and their fleas, since they could be important reservoirs of this bacterium in northern Mexico.

Extracts of the Canadian goldenrod (Solidago Canadensis L.) – promising agents with antimicrobial, anti-inflammatory and hepatoprotective activity

S. canadensis L. and S. virgaurea L. are the most common species of Solidago L. in Europe and with a long tradition of use in medicine for various therapeutic purposes: diseases of the urinary tract, gastrointestinal tract, diabetes, allergies and antiseptic purposes. Therefore, the research of species of the Solidago genus, which have a rich content of natural BACs, and the development of new effective medicinal products of plant origin are relevant. The aim. The method of work is the phytochemical and pharmacological study of extracts of the Canadian goldenrod herb, obtained by ethanol solutions of various concentrations, for the innovative perspective of creating new medicines based on them with antimicrobial, anti-inflammatory and hepatoprotective activity. Materials and methods. The objects of the study were extracts of herb from Canadian goldenrod, obtained using purified water, 40 %, 70 % and 90 % ethanol. Phytochemical study of the extracts was performed by TLC and spectrophotometry. Study of acute toxicity, antimicrobial, anti-inflammatory and hepatoprotective activity of extracts was carried out according to standard methods. Research results. A study of the phytochemical composition and pharmacological activity of extracts of herb from Canadian goldenrod obtained with different solvents. It was established that extracts of herb from Canadian goldenrod show anti-inflammatory activity. The most pronounced antiexudative activity is shown by the extract of the Canadian goldenrod herb (extractant - 40 % ethanol), reducing the degree of swelling by 24.77 %. Herb extracts from from Canadian goldenrod in acute toxic liver damage show moderate hepatoprotective activity, which is somewhat inferior to the comparative drug "Silibor". A more intense and effective effect on the hepatobiliary system was shown by the extract of the Canadian goldenrod herb (extractant - 40 % ethanol). Conclusions. The perspective of creation based on herb of Canadian goldenrod new drugs with hepatoprotective activity. The most promising substance turned out to be an extract of herb from Canadian goldenrod obtained with a 40 % ethanol solution.

Community structure and assembly of myxomycetes in northern Chinese forests under geographic barriers

ABSTRACT The study of myxomycete biogeography has a long-standing history and has consistently drawn scholarly interest. Nevertheless, studies focusing specifically on the spatial and temporal distribution patterns of myxomycete diversity are relatively limited, with even fewer investigating the mechanisms driving the generation and maintenance of myxomycete diversity. Therefore, this study selected two geographically distant sampling sites within northern Chinese forests to investigate myxomycete species composition, community structure, environmental drivers, and assembly patterns under geographic barriers. We established plots in the Altai Mountains (ALE) and the Greater Khingan Mountains (GKM), gathered bark and litter, and conducted 80-day moist chamber cultures of myxomycetes. Additionally, myxomycete specimens were collected in the field simultaneously to supplement the data set. This study collected 541 myxomycete specimens belonging to 73 species from 28 genera, spanning 12 families and eight orders. The ALE and the GKM had 20 identical species, accounting for 27% of the total species. Myxomycetes from both regions exhibited abundant occurrence 18 days after cultivation, with the quantity on bark substrates notably higher than on litter. Arcyria pomiformis and Comatricha elegans were the most common species in moist chamber cultures. Mantel test outcomes revealed that environmental factors had no significant impact on myxomycete community similarity between the two areas, aligning with findings from the neutral community model analysis, indicating a predominant influence of stochastic processes on myxomycete community structure in moist chamber cultures. This study represents the first application of a quantitative framework to analyze myxomycete community assembly cultivated in moist chambers.

Role of Urban Trees in Enhancing the Thermal Comfort of Rapidly Urbanizing Cities: An Analysis of Tropical Asian Tree Species Based on Physiological Equivalent Temperature (PET)

AbstractBackgroundThermal comfort significantly influences well-being, productivity, and living conditions in outdoor environments, particularly in rapidly urbanizing, warm, humid tropical climates. This study assessed the influence of 5 five common urban tree species (Cassia fistula,Tectona grandis,Plumeria obtusa,Mangifera indica, andTerminalia catappa) on outdoor thermal comfort, using the physiological equivalent temperature (PET) index in Colombo, Sri Lanka, as a case study for a tropical humid city.MethodsField data collection encompassed measuring air and surface temperature, relative humidity, wind velocity, solar radiation, cloud cover, and sky view factor under tree canopies and adjacent exposed areas. The RayMan model was employed to estimate PET in both areas.ResultsOur findings indicated that PET was consistently higher in exposed areas compared to under the tree canopy, with an average difference of 5.61 °C. Among tree parameters, sky view factor (SVF) demonstrated the most significant correlation with thermal comfort, followed by crown diameter and tree height. Furthermore, notable variations in thermal comfort were observed among tree species, withTerminalia catappaoutperformingPlumeria obtusa, particularly on sunny days.ConclusionRegression analysis highlighted the importance of integrating trees with large crowns and low SVF to create thermally comfortable outdoor spaces. Consequently,Terminalia catappaemerged as the most suitable tree species for enhancing thermal comfort in Colombo’s outdoor urban areas out of the 5 selected species. These insights will aid in selecting appropriate tree species and parameters, fostering improved outdoor thermal comfort in tropical humid cities, and facilitating sustainable urban planning and design strategies.

Development of a Multiplex Real-Time PCR Assay for the Simultaneous Detection of Two Fungal Pathogens Causing Pneumonia.

Infectious diseases caused by fungal sources are of great interest owing to their increasing prevalence. Invasive fungal infections, including invasive pulmonary aspergillosis caused by Aspergillus fumigatus, and Pneumocystis pneumonia caused by Pneumocystis jirovecii, are significant causes of morbidity and mortality among immunocompromised patients. The accurate and timely detection of these pathogens in this high-risk population is crucial for effective patient management. We developed a multiplex real-time polymerase chain reaction (PCR) assay, RF2 mRT-PCR, specifically designed to detect two respiratory fungi, P. jirovecii and A. fumigatus, and evaluated its performance in specimens of patients with lower respiratory tract infection. The performance was evaluated using 731 clinical samples, 55 reference species, and one synthetic DNA. The reproducibility test yielded a probit curve with a lower limit of detection of 19.82 copies/reaction for P. jirovecii and 64.20 copies/reaction for A. fumigatus. The RF2 mRT-PCR assay did not cross-react with non-A. fumigatus Aspergillus species or other common bacterial and viral species, and showed 100% in vitro sensitivity and specificity with reference assays. Additionally, it simultaneously detected A. fumigatus and P. jirovecii in co-infected samples. Therefore, the RF2 mRT-PCR assay is an efficient and reliable tool for in vitro diagnosis of A. fumigatus and P. jirovecii pulmonary infections.

Distribution of Bovine Mastitis Pathogens in Quarter Milk Samples from Bavaria, Southern Germany, between 2014 and 2023-A Retrospective Study.

The objective of this study was to investigate the distribution of mastitis pathogens in quarter milk samples (QMSs) submitted to the laboratory of the Bavarian Animal Health Service (TGD) between 2014 and 2023 in general, in relation to the clinical status of the quarters, and to analyze seasonal differences in the detection risk. Each QMS sent to the TGD during this period was analyzed and tested using the California Mastitis Test (CMT). Depending on the result, QMSs were classified as CMT-negative, subclinical, or clinical if the milk character showed abnormalities. Mastitis pathogens were detected in 19% of the QMSs. Non-aureus staphylococci (NAS) were the most common species isolated from the culture positive samples (30%), followed by Staphylococcus (S.) aureus (19%), Streptococcus (Sc.) uberis (19%), and Sc. dysgalactiae (9%). In culture-positive QMSs from CMT-negative and subclinically affected quarters, the most frequently isolated pathogens were NAS (44% and 27%, respectively), followed by S. aureus (25% and 17%, respectively) and Sc. uberis (8% and 22%, respectively). In QMSs from clinically affected quarters, the most frequently isolated pathogens were Sc. uberis (32%), S. aureus (13%), Sc. dysgalactiae (11%), and Escherichia (E.) coli (11%). The distribution of NAS and Sc. uberis increased throughout the study period, while that of S. aureus decreased. From June to October, QMSs from subclinically affected quarters increased and environmental pathogens, such as Sc. uberis, were detected more frequently. In conclusion, this study highlights the dynamic nature of the distribution of mastitis pathogens, influenced by mastitis status and seasonal factors. Environmental pathogens still play an important role, especially in clinical mastitis and seasonal dependency, with the number of positive samples continuing to increase. It is therefore essential to continue mastitis control measures and to regularly monitor the spread of mastitis pathogens in order to track trends and adapt targeted prevention measures.

Early Growth and Physiological Acclimation to Shade and Water Restriction of Seven Sclerophyllous Species of the Mediterranean Forests of Central Chile.

The success of using active restoration in Mediterranean-type climate zones mostly depends on an appropriate matching of plant species and specific management prescriptions upon establishment. In this study, we assessed the early growth and short-term physiological acclimation of seven common species found in the sclerophyllous forests in central Chile to water restriction and shading. We established a nursery experiment that included three treatments (T0: sun-exposed and water-restricted, T1: sun-exposed and fully irrigated, and T2: shaded and fully irrigated) and seven tree species differing in their shade and drought tolerance (Quillaja saponaria Molina, Aristotelia chilensis (Mol.) Stuntz, Peumus boldus Molina, Lithraea caustica (Mol.) Hook. and Arn, Luma apiculata (DC.) Burret, Colliguaja odorifera Molina, and Escallonia pulverulenta (Ruiz and Prav.) Pers). We measured the increment in seedling height and different leaf morpho-physiological traits during two months in the dry season. Based on the measured traits, none of the species took advantage of the higher water availability in T1 relative to T0, but most of the species responded to the shade in T2, regardless of their shade or drought tolerance. Height increments due to shade varied from 0% in P. boldus to 203% in L. apiculata. Overall, all the species responded similarly to the treatments in specific leaf area, chlorophyll content index, photosynthetic rate, stomatal conductance, and intrinsic water use efficiency. This suggests that the species exhibited similar acclimation patterns of these parameters to shade and drought, even regarding the variation in midday xylem water potential found in the water-restricted treatment T0 (from -1.5 MPa in P. boldus to -3.1 MPa in E. pulverulenta). In this study, shading had a higher positive effect on the seedling performance of sclerophyllous species than watering, which at operational level highlights the need for investing in tree shelters when using these species in restoration programs.

Nitrogen deposition enhances the competitive advantage of invasive plant species over common native species through improved resource acquisition and absorption

BackgroundPrevious studies into the interactions between native and invasive species under nitrogen (N) deposition have often overlooked the presence of co-occurring native species, a factor that could influence the outcomes of interspecific competition. Furthermore, publication bias may lead researchers to focus on rare native species with limited adaptability. In this study, we examined how two levels of N deposition affected the physiological and ecological traits and the interspecies interactions between three invasive and three common native species.ResultsN deposition promoted the growth of both invasive and native species. The relative dominance index (RDI) of invasive species was consistently higher than that of native species. Invasive species had an advantage over common native species in using the increased N effectively. The biomass distribution of invasive species was biased toward the aboveground parts, indicating competition for light resources.ConclusionsN deposition conferred a stronger competitive advantage to invasive species than to native species, suggesting that the distribution range of invasive species may expand further under increased N deposition.

Dry inside: progressive unsaturation within leaves with increasing vapour pressure deficit affects estimation of key leaf gas exchange parameters.

Climate change not only leads to higher air temperatures but also increases the vapour pressure deficit (VPD) of the air. Understanding the direct effect of VPD on leaf gas exchange is crucial for precise modelling of stomatal functioning. We conducted combined leaf gas exchange and online isotope discrimination measurements on four common European tree species across a VPD range of 0.8-3.6 kPa, while maintaining constant temperatures without soil water limitation. In addition to applying the standard assumption of saturated vapour pressure inside leaves (ei), we inferred ei from oxygen isotope discrimination of CO2 and water vapour. ei desaturated progressively with increasing VPD, consistently across species, resulting in an intercellular relative humidity as low as 0.73 ± 0.11 at the highest tested VPD. Assuming saturation of ei overestimated the extent of reductions in stomatal conductance and CO2 mole fraction inside leaves in response to increasing VPD compared with calculations that accounted for unsaturation. In addition, a significant decrease in mesophyll conductance with increasing VPD only occurred when the unsaturation of ei was considered. We suggest that the possibility of unsaturated ei should not be overlooked in measurements related to leaf gas exchange and in stomatal models, especially at high VPD.

Reassessment of French breeding bird population sizes using citizen science and accounting for species detectability.

Higher efficiency in large-scale and long-term biodiversity monitoring can be obtained through the use of Essential Biodiversity Variables, among which species population sizes provide key data for conservation programs. Relevant estimations and assessment of actual population sizes are critical for species conservation, especially in the current context of global biodiversity erosion. However, knowledge on population size varies greatly, depending on species conservation status and ranges. While the most threatened or restricted-range species generally benefit from exhaustive counts and surveys, monitoring common and widespread species population size tends to be neglected or is simply more challenging to achieve. In such a context, citizen science (CS) is a powerful tool for the long-term monitoring of common species through the engagement of various volunteers, permitting data acquisition on the long term and over large spatial scales. Despite this substantially increased sampling effort, detectability issues imply that even common species may remain unnoticed at suitable sites. The use of structured CS schemes, including repeated visits, enables to model the detection process, permitting reliable inferences of population size estimates. Here, we relied on a large French structured CS scheme (EPOC-ODF) comprising 27,156 complete checklists over 3,873 sites collected during the 2021-2023 breeding seasons to estimate the population size of 63 common bird species using hierarchical distance sampling (HDS). These population size estimates were compared to the previous expert-based French breeding bird atlas estimations, which did not account for detectability issues. We found that population size estimates from the former French breeding bird atlas were lower than those estimated using HDS for 65% of species. Such a prevalence of lower estimations is likely due to more conservative estimates inferred from semi-quantitative expert-based assessments used for the previous atlas. We also found that species with long-range songs such as the Common Cuckoo (Cuculus canorus), Eurasian Hoopoe (Upupa epops) or the Eurasian Blackbird (Turdus merula) had, in contrast, higher estimated population sizes in the previous atlas than in our HDS models. Our study highlights the need to rely on sound statistical methodology to ensure reliable ecological inferences with adequate uncertainty estimation and advocates for a higher reliance on structured CS in support of long-term biodiversity monitoring.

Assessment of Suitable Growth Condition of Salvinia spp. for Sustainability of Floating Agriculture to Mitigate Climate Change Challenges on Crop Cultivation

Floating agriculture is an indigenous cultivation practice in the southern waterlogged areas of Bangladesh. Water hyacinth and other macrophytes were utilized in this agricultural method to prepare the floating bed. Among the numerous macrophytes used as mulch in floating beds, Salvinia spp. is a common species. To meet the local farmer's demand, it is necessary to improve the growth rates of these macrophytes so that they can be available year-round for preparing floating beds. For this purpose, an experiment was conducted to assess the growth conditions of Salvinia spp. under various nutritional media. Salvinia molesta and Salvinia cucullata were cultivated in four healthy media to carry out the experiment. The experimental design used in the present investigation was a split-plot arrangement in a Randomized Block Design (RBD), where four nutrients (NO3-; PO43-; NH4+ and Urea) were assigned to the main plots, while five different concentrations of nutrient (0, 1, 5, 10 and 15 mM) were given to the sub-plots. Salvinia spp. growth was examined in terms of morphological and physiological responses and the distribution of nutrients. The highest relative growth rate (RGR) and biomass production (g DW) were found in the medium with one mM and five mM PO43- in the case of S. molesta and one mM NH4+ in the case of S. cucullata. It was also observed that the plant growth rate became suppressed when this macrophyte grew above the 5mM of nutrient concentration, and this suppressed condition turned into a toxic state when the organic nutrient concentration reached a concentration of 15 mM or above. In the case of Urea, this harmful condition starts with a concentration of 5 mM or more for S. molesta and any concentration for S. cucullata.Nonetheless, very few variations were found in how various plant tissues and species absorbed mineral concentrations. The overall findings from this experiment indicate that both PO43- and NH4+ concentrations of 1 mM and 5 mM are comparatively more suitable than NO3- and Urea for the growth and multiplication of Salvinia spp. However, more research is required in addition to varying the quantities of phosphate and ammonium to make a definitive choice. J. of Sci. and Tech. Res. 5(1): 53-62, 2023

Arthropod traits as proxies for abundance trends in the Azorean Islands

Human activities drive ecological transformation, impacting island ecosystems from species diversity to ecological traits, mainly through habitat degradation and invasive species. Using two unique long‐term datasets we aim to evaluate whether species traits (body size, trophic level, dispersal capacity and habitat occupancy) can predict temporal variations in the abundance of endemic, indigenous (endemic and native non‐endemic) and exotic arthropods in the Azores Islands. We found that body size is crucial to predict arthropod abundance trends. Small‐bodied herbivorous arthropods showed a decrease in abundance, while large‐bodied indigenous arthropods increased in abundance, mainly in well‐preserved areas. Also, large‐bodied exotic arthropods increased in abundance across the entire archipelago. Moreover, endemic canopy dwellers increased in abundance, while endemic ground‐dwellers decreased in abundance. Simultaneously, exotic arthropods showed the opposite result, increasing in abundance in the ground while decreasing in abundance in the canopy. Finally, habitat influenced both endemic and exotic spider abundance trends. Endemic spiders that occupy solely natural habitats experienced a decline in abundance, while exotic spiders in the same habitats increased in abundance. Our study underscores the significance of arthropod species traits in predicting abundance changes in island ecosystems over time, as well as the importance of monitoring species communities. Conservation efforts must extend beyond endangered species to protect non‐threatened ones, given the increased extinction risk faced by even common species on islands. Monitoring and restoration programs are essential for preserving island ecosystems and safeguarding endemic arthropod populations.

Phenological Analysis of Grasses (Poaceae) in Comparison with Aerobiological Data in Moscow (Russia).

Grasses (Poaceae) produce large amounts of pollen and are among the main causes of pollinosis worldwide. Despite their morphological similarity, pollen grains of different grass species may have different allergenicities. Therefore, quantification of the roles of individual species in airborne pollen is an important task. There are very few studies on this topic, and none of them have been conducted in a temperate continental climate. Our study was carried out for three years (2020-2022) in the urban territory of Moscow (Russia) and aimed to understand what grass species contribute the most to the total pollen load of the atmosphere. The comparison of aerobiological and phenological data was based on calculating the phenological index, which is a combination of phenological parameters, pollen productivity of individual species, and their abundance. Our data showed that the decomposition of pollination curves based on the phenological index was sometimes very efficient but not always possible in temperate continental climates. The main reasons for disagreement between aerobiological and phenological data were weather conditions and lawn mowing. Not all grasses were equally important as sources of allergenic pollen. The greatest contribution to the pollen load at the beginning of the season in Moscow was made by Dactylis glomerata, and to a lesser extent by Phleum pratense and Festuca pratensis. These are the most common species, which are widespread throughout Europe. The contribution of minor components is insignificant.

Metabolic capabilities are highly conserved among human nasal-associated Corynebacterium species in pangenomic analyses.

Corynebacterium species are globally ubiquitous in human nasal microbiota across the lifespan. Moreover, nasal microbiota profiles typified by higher relative abundances of Corynebacterium are often positively associated with health. Among the most common human nasal Corynebacterium species are C. propinquum, C. pseudodiphtheriticum, C. accolens, and C. tuberculostearicum. To gain insight into the functions of these four species, we identified genomic, phylogenomic, and pangenomic properties and estimated the metabolic capabilities of 87 distinct human nasal Corynebacterium strain genomes: 31 from Botswana and 56 from the USA. C. pseudodiphtheriticum had geographically distinct clades consistent with localized strain circulation, whereas some strains from the other species had wide geographic distribution spanning Africa and North America. All species had similar genomic and pangenomic structures. Gene clusters assigned to all COG metabolic categories were overrepresented in the persistent versus accessory genome of each species indicating limited strain-level variability in metabolic capacity. Based on prevalence data, at least two Corynebacterium species likely coexist in the nasal microbiota of 82% of adults. So, it was surprising that core metabolic capabilities were highly conserved among the four species indicating limited species-level metabolic variation. Strikingly, strains in the USA clade of C. pseudodiphtheriticum lacked genes for assimilatory sulfate reduction present in most of the strains in the Botswana clade and in the other studied species, indicating a recent, geographically related loss of assimilatory sulfate reduction. Overall, the minimal species and strain variability in metabolic capacity implies coexisting strains might have limited ability to occupy distinct metabolic niches.

The Sec pathway gene yidC regulates the virulence of mesophilic Aeromonassalmonicida

Aeromonas salmonicida is a common pathogenic bacterial species found in both freshwater and marine fish, leading to significant economic losses in the aquaculture industry. YidC is an accessory to SecYEG and is essential for the SecYEG transporter to insert into the bacterial membrane. However, the roles of the yidC gene on the host immune response remain unclear. Here, we compared the pathogenicity of yidC gene-deleted (ΔyidC) strain and wild-type (SRW-OG1) strain of mesophilic A. salmonicida to Orange-spotted grouper (Epinephelus coioides), and explored the impacts of yidC gene on the immune response of E. coioides to mesophilic A. salmonicida infection by using Red/ET recombineering. In this study, the E. coioides in the Secondary infected group had a 53.9 % higher survival rate than those in the Primary infected group. In addition, the adhesion ability of ΔyidC strain decreased by about 83.36 % compared with that of the wild-type (SRW-OG1) strain. Further comparison of the biological phenotype of SRW-OG1 and ΔyidC revealed that this yidC gene could regulate the expression of genes related to iron metabolism and have no effect on bacterial growth under the limited iron concentration. In the low concentration of Fe3+ and Fe2+ environment, SRW-OG1 can obtain iron ions by regulating yidC. Based on the above results, yidC gene contributed to the pathogenicity of mesophilic A. salmonicida to E. coioides, deletion of yidC gene promoted the inflammation and immune response of E. coioides to mesophilic A. salmonicida infection.

Diversity of Seedlings in the Kerangas Forest Kersik Luway Nature Reserve

The Extreme Kerangas Forest is an edapic type of kerangas forest dominated by a much higher quartz sand content than the soil. However, the vegetation in this area is still abundant and the species have their own criteria that are very distinctive and different from other forest types. This paper describes in detail the investigation of seedling variety in the extreme Kerangas Forest of the Kersik Luway Nature Reserve. The research focuses on sapling vegetation in a 1-hectare area of this unique forest type, which is distinguished by high quartz sand content in the soil. The study methodologies are thoroughly described, including the application of the sensus method. The investigation found 38,225 unique saplings representing 16 species from 13 different groups. The most common species were Tristania obovata, Ilex hypoglauca Laec, Podocarpus neriifolius D.Don, Ficus sp. and Calophyllum glaucum. These species thrive in the Kerangas forest's nutrient-poor, acidic soils. According to the report, conservation efforts should prioritize the preservation of these unique ecosystems as well as the rehabilitation of barren areas containing rare species. The severe Kerangas forest in the Nature Reserve is home to a broad assortment of species that have evolved to thrive in harsh environments.

Evaluation of the long-term effects of formaldehyde on the physiology of the Mediterranean mussel, Mytilusgalloprovincialis

Formalin baths are the most widely used treatment for ectoparasitic fish diseases. Nonetheless, their use in fish cages has been blamed for a number of problems. Although a considerable amount of literature has been produced on the short-term toxic effects of formaldehyde, there is virtually no data on the long-term side effects of the compound on non-target organisms. Therefore, the purpose of this research was to assess the long-term formaldehyde toxicity in Mediterranean mussel, Mytilus galloprovincialis, a common sentinel species that inhabits the area surrounding cage farms. Mussels were kept in a laboratory microenvironment at 20 ± 1 °C for 21 days and exposed to two different formaldehyde concentrations during experimentation: a low dose (L; 40 ppb) based on formaldehyde field measurements in the vicinity of Mediterranean cages, and a high dose (H; 400 ppb) generated by a factor of 10 of the previous dose. A multi-biomarker approach that included antioxidant enzymes such as catalase (CAT) and superoxide dismutase (SOD), lipid peroxidation (MDA), lysosomal stability (NRRT), genotoxicity tests, condition index (CI), and stress on stress (SoS), was used to evaluate the toxicity of formaldehyde on mussels. The results of the selected tests indicate that formaldehyde does not cause chronic toxicity in mussels subjected to commonly measured concentrations in the aquatic environment following formalin bath treatments. Despite being defined as reversible, the stress brought by the high dose used seems to reduce the antioxidant activity of the tested organism. The significance of this research lies in its contribution to understanding the wider ecological effects of formaldehyde exposure. Moreover, the results highlight the need for further research on other non-target marine organisms to fully understand the cumulative effects of formaldehyde on marine ecosystems.

Phylogeny of Meloidogyne incognita (Nematoda: Heteroderidae) using mtDNA from Limpopo Province, South Africa

Identification of Meloidogyne species is difficult using classical techniques alone, as some species have similar characteristics. Meloidogyne incognita is a plant-parasitic nematode that is one of the four most common species worldwide and has numerous hosts, including tomato (Solanum lycopersicum L.). This nematode is regarded as the most significant contributing factor to the reduction in tomato yield. Therefore, the present investigation was conducted in 2024 at the University of Limpopo to identify M. incognita. The COI mtDNA was sequenced and amplified from female nematodes, following which the blast result showed that the South African population exhibited a high similarity (100% identity) to those populations studied in China (MH743221 and MH743220). Utilizing the Maximum Likelihood method for phylogenetic analysis, it was demonstrated that our population and the other populations of M. incognita form a robust clade (87% bootstrap values).

Epidemiology and antibiotic resistance of staphylococci on commercial pig farms in Cape Town, South Africa

Staphylococci are responsible for a wide range of infections in animals. The most common species infecting animals include Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus intermedius. Recent increases in antibiotic use and antibiotic resistance in animals highlight the need to understand the potential role of commercial livestock as a reservoir of staphylococci and antibiotic resistance genes. Nasal swabs were collected from 143 apparently healthy pigs and 21 pig farm workers, and 45 environmental swabs of feed and water troughs, from two commercial pig farms in the Western Cape, South Africa. Staphylococci were isolated, identified using mass-spectrometry, and antimicrobial susceptibility testing and Illumina whole genome sequencing were performed. One hundred and eighty-five (185) Staphylococcus spp. isolates were obtained, with Mammalicoccus sciuri (n = 57; 31%) being the most common, followed by S. hyicus (n = 40; 22%) and S. aureus (n = 29; 16%). S. epidermidis was predominantly identified in the farm workers (n = 18; 86%). Tetracycline resistance was observed across all species, with rates ranging from 67 to 100%. Majority of M. sciuri isolates (n = 40; 70%) were methicillin resistant, with 78% (n = 31) harbouring mecA. M. sciuri isolates had genes/elements which were associated with SCCmec_type_III (3A) and SCCmec_type_VIII(4A) and were mostly observed in ST61 strains. ST239 strains were associated with SCCmec_type_III(3A). High rates of tetracycline resistance were identified among staphylococci in the pig farms in Western Cape, South Africa. This highlights the need for policy makers to regulate the use of this antibiotic in pig farming.

Phenotypic limits of crop diversity: a data exploration of functional trait space.

Relationships between crop genetic and functional diversity are key to addressing contemporary agricultural challenges. Yet, there are few approaches for quantifying the relationship between genetic diversity and crop functional trait expression. Here, we introduce 'functional space accumulation curves' to analyze how trait space increases with the number of crop genotypes within a species. We explore the potential for functional space accumulating curves to quantify genotype-trait space relationships in four common annual crop species: barley (Hordeum vulgare), rice (Oryza sativa), soybean (Glycine max), and durum wheat (Triticum durum). We also employ these curves to describe genotype-trait space relationships in the wild annual Arabidopsis thaliana, which has not been subjected to artificial selection. All five species exhibited asymptotic functional space accumulation curves, suggesting a limit to intraspecific functional crop diversity, likely due to: dominant phenotypes represented by several genotypes;or functional redundancy that might exist among genotypes. Our findings indicate that there is a diminishing return of functional diversity with increasing number of genotypes. Our analysis demonstrates the efficacy of functional space accumulation curves in quantifying trait space occupancy of crops, with implications for managing crop diversity in agroecosystems, and genetic diversity in crop breeding programs.