Occurrence and Habitat Characteristics of Aurelia sp. Polyps in a High-Latitude Fjord

Causes and consequences of jellyfish bloom formation are subject to controversial discussions worldwide. While medusae have been studied to a broader extent, the knowledge on polyp stages of scyphozoans is limited thus hampering reliable prediction of jellyfish bloom formation. This study describes the occurrence, abundance, habitat characteristics and interactions of scyphozoan Aurelia sp. polyp colonies with other fouling organisms in intertidal and subtidal sectors of Trondheimsfjorden (Norway). In total, 982 polyps were found on 70 substrata of varying material types during a field survey in spring-summer 2018 along a longitudinal gradient within and outside Trondheimsfjorden. The polyps were identified as Aurelia sp. based on molecular species identification. Most polyps were found in bays with macroalgae canopy on the down facing side of artificial and natural substrata (rocks, concrete, iron) and inside rock cracks. Polyp microhabitats included the surface of Ascidia mentula (solitary ascidian), increments of Pomatoceros triqueter (polychete) tubes and dead Balanus balanoides (barnacle) shells. Based on the deployment of settling plates, abundance of Aurelia sp. polyps ranged from 1.2 (± 0.7) to 0.12 (± 0.07) polyps cm–2. Settlement occurred either directly on the PVC settling plates or as epibionts on the ascidian Ascidia mentula and on barnacle shells of Balanus balanoides. This study provides insights into the potential of local Aurelia sp. polyps contributing to the seasonal occurrence and abundance of Aurelia sp. in fjord systems, where intensive blooms occur annually.

Antimicrobial susceptibility and molecular species identification of clinical carbapenem-resistant bacteria

Inggraini M, Nurfajriah S, Priyanto JA, Ilsan NA. 2021. Antimicrobial susceptibility and molecular species identification of clinical carbapenem-resistant bacteria. Biodiversitas 22: 555-562. Antibiotic is the first option treatment for infectious diseases both in human and animal. However, the excessive usage and misuse of antibiotics have driven antibacterial resistances worldwide and the increasing case of antibiotic resistance leads to limited options for treatment. This study aimed to observe antimicrobial susceptibility and molecular identification of carbapenem-resistant human clinical bacteria. A total of nine isolates in this study were collected in 2020 from a teaching hospital in Indonesia. All isolates were originated from various human clinical specimens, including urine, blood, pus, and sputum. Identification using 16s rRNA-based showed that these isolates were closely related to Klebsiella pneumoniae (1/9), A. baumannii (5/9), Escherichia coli (2/9), and Lysinibacillus fusiformis (1/9). According to minimum inhibitory concentration using Vitek Automated Machine, four isolates of multi-drug resistant (MDR) bacteria were found. In contrast, five of them were categorized as extensively-drug resistant (XDR). Interestingly, all of the XDR isolates belonged to A. baumannii. These isolates were resistant to at least seven different antimicrobial classes. A comparison of partial 16s rRNA showed two E. coli had similar variance. While in A. baumannii isolates, we found one of five isolates had a different variance sequence, which suggests different clonality among this species. This study gives an insight into the prevalence of carbapenem-resistant bacteria with XDR criteria in Indonesia.

Sampling and processing of freshwater nematodes with emphasis on molecular methods.

This chapter provides an introduction to current methods of nematode sampling and processing, with the latter including molecular methods as well. It highlights that nematode sampling and processing for different habitats will require different sampling methods; nematode identification can be achieved with morphological or molecular approaches; the analysis of specific gene fragments can be used to delimitate nematode species; and molecular species identification can give further information about phylogenetic background and cryptic species.

Low rate of azole resistance in cases of avian aspergillosis in Germany

Aspergillosis is the most common fungal disease of the avian respiratory tract. Due to delayed diagnosis and treatment failure, the outcome of these infections is often poor. We investigate 159 cases of avian aspergillosis among captive birds in Germany to define clinical features as well as the frequency of in vitro triazole resistance. Adult birds were more likely to present with clinical signs compared to juvenile birds, and dyspnoea was the most common clinical sign, present in 53% of birds. Molecular species identification indicated that all infections were caused by Aspergillus fumigatus. Only one of 159 independent isolates was azole resistant.

Upsurge of malaria transmission after indoor residual spraying withdrawal in Atacora region in Benin, West Africa

Background In Benin, malaria vector control mostly relies on long-lasting, insecticidal-treated bed nets (LLINs) and indoor residual spraying (IRS) operations. From 2011 to 2016, an IRS programme has been implemented in Atacora region. However, in 2017 the programme was withdrawn from two other regions in the northern part of the country, with hopes that gains would be relatively sustained because of the seasonality of malaria transmission. What would be the vulnerability of populations to malaria after the withdrawal of IRS? Methods Monthly mosquito collections were performed through human landing captures (HLCs) for 24 months (from January to December 2016 during the last IRS campaign, and from January to December 2018, 2 years after the withdrawal of IRS). Vector mosquitoes biting density was sampled by HLC and was tested for presence of Plasmodium falciparum sporozoites. The carcass of these mosquitoes (abdomens, wing, legs) were subjected to molecular species identification using polymerase chain reaction (PCR) assays. Results It is noticed a drastic increase (~ 3 times higher) of vector abundance after the withdrawal of IRS. Mosquito biting rates in the 3 survey districts increased significantly after IRS was withdrawn. In 2018, after IRS cessation a significant increase of entomological inoculation rate was recorded, where each inhabitant received an average of 94.9 infected bites/year to 129.21 infected bites/year against an average of 17.15 infected bites/year to 24.82 infected bites/year in 2016. Conclusion It is obvious that the withdrawal of IRS confers a vulnerability of the population with regard to the malaria transmission. Robust monitoring is needed to better understand when and where IRS should be most adequate, or can be safely withdrawn. In case of withdrawal, adapted accompanying measures should be proposed according to the context not only to maintain the gains capitalized with IRS, but also to avoid any rebound of transmission.

Hidden biodiversity revealed by integrated morphology and genetic species delimitation of spring dwelling water mite species (Acari, Parasitengona: Hydrachnidia)

Background Water mites are among the most diverse organisms inhabiting freshwater habitats and are considered as substantial part of the species communities in springs. As parasites, Hydrachnidia influence other invertebrates and play an important role in aquatic ecosystems. In Europe, 137 species are known to appear solely in or near springheads. New species are described frequently, especially with the help of molecular species identification and delimitation methods. The aim of this study was to verify the mainly morphology-based taxonomic knowledge of spring-inhabiting water mites of central Europe and to build a genetic species identification library. Methods We sampled 65 crenobiontic species across the central Alps and tested the suitability of mitochondrial (cox1) and nuclear (28S) markers for species delimitation and identification purposes. To investigate both markers, distance- and phylogeny-based approaches were applied. The presence of a barcoding gap was tested by using the automated barcoding gap discovery tool and intra- and interspecific genetic distances were investigated. Furthermore, we analyzed phylogenetic relationships between different taxonomic levels. Results A high degree of hidden diversity was observed. Seven taxa, morphologically identified as Bandakia concreta Thor, 1913, Hygrobates norvegicus (Thor, 1897), Ljania bipapillata Thor, 1898, Partnunia steinmanni Walter, 1906, Wandesia racovitzai Gledhill, 1970, Wandesia thori Schechtel, 1912 and Zschokkea oblonga Koenike, 1892, showed high intraspecific cox1 distances and each consisted of more than one phylogenetic clade. A clear intraspecific threshold between 5.6–6.0% K2P distance is suitable for species identification purposes. The monophyly of Hydrachnidia and the main superfamilies is evident with different species clearly separated into distinct clades. cox1 separates water mite species but is unsuitable for resolving higher taxonomic levels. Conclusions Water mite species richness in springs is higher than has been suggested based on morphological species identification alone and further research is needed to evaluate the true diversity. The standard molecular species identification marker cox1 can be used to identify species but should be complemented by a nuclear marker, e.g. 28S, to resolve taxonomic relationships. Our results contribute to the taxonomical knowledge on spring inhabiting Hydrachnida, which is indispensable for the development and implementation of modern environment assessment methods, e.g. metabarcoding, in spring ecology.

Morphological and Molecular Species Identification of Termites Attacking Ironwood Trees, Casuarina equisetifolia (Fagales: Casuarinaceae), in Guam

Ironwood trees (Casuarina equisetifolia subsp. equisetifolia L.) are ecologically and economically important trees in tropical and subtropical regions of the Indo-Pacific. Ironwood is one of the dominant tree species in Guam, but since 2002, this tree has been declining dramatically. A previous study showed that numerous sick or dead trees were under termite attack. However, the species of termites were not identified. As a first step to investigate causal relationships between termites and ironwood tree death, we assigned termites collected from ironwood trees to species using a combination of morphological characters and DNA barcoding of the 12S, 16S, COI, COII, and ITS2 regions. Based on morphology and comparisons to reference sequences in NCBI GenBank, the most likely species assignments were Nasutitermes takasagoensis (Nawa) (Blattodea: Termitidae) found to infest 45 trees, followed by Coptotermes gestroi (Wasmann) (Blattodea: Rhinotermitidae) (2 trees), Microcerotermes crassus Snyder (Blattodea: Termitidae) (2 trees), and an additional unidentified Microcerotermes species (1 tree) with no close sequence match to identified species in NCBI GenBank. However, taxonomic revisions and broader representation of DNA markers of well-curated specimen in public databases are clearly needed, especially for the N. takasagoensis species complex.