Blood-sucking insects, such as lice, act as potential vectors of vector-borne pathogens. The proposed study aimed to diagnose molecularly Bartonella sp., an arthropod-borne bacterium in Microthoracius lice collected from alpacas in Peru. Ninety-six lice of the Microthoracius genus were collected from alpaca crias from the Quenamari and Chillihua communities from Cuzco, Peru. All lice were molecularly analyzed by PCR protocols for Bartonella sp. Bartonella genus detection was performed by amplifying the 16S-23S internal transcribed spacer (ITS) region. Bartonella species were identified amplifying the citrate synthase gene (gltA), the RNA polymerase beta-subunit gene (rpoB), and the cell division protein gene (ftsZ). Bartonella DNA was detected in 33.3% (32/96) lice. M. mazzai had the highest Bartonella prevalence (50%; 10/20), followed by M. praelongiceps (28.9%; 22/76). Sequencing of PCR products of fragments of the gltA, rpoB, and ftsZ genes showed homology of 100%, 99.8-100%, and 99.4-99.9%, respectively, with Bartonella dromedarii. No statistical association was observed between B. dromedarii-like detection and louse species and communities. This study records for the first time the occurrence of Bartonella in alpaca lice and suggests that these insects may act as potential vectors for these pathogens, but further, more detailed studies are required. As Microthoracius lice are common camelid ectoparasites, future studies will be necessary to understand the situation of bartonellosis by B. dromedarii-like in domestic and wild South American camelids in various regions of the Peruvian Andes.

Bartonella infective endocarditis (IE) is a rare cause of initially blood culture-negative IE, classically associated with cat flea exposure in Bartonella henselae infection or body lice infestation among individuals experiencing homelessness or alcoholism in Bartonella quintana infection. We report the case of an 84-year-old man with severe calcific aortic stenosis who was undergoing evaluation for pre-transcatheter aortic valve implantation (TAVI). Cardiac computed tomography (CT) unexpectedly revealed a peri-annular cavity consistent with a drained or healed peri-annular abscess, despite the absence of fever or other clinical features of IE. Initial blood cultures were negative, and TAVI was planned following multidisciplinary discussion, pending serological results. However, a subsequently reported high-titer Bartonella serology prompted readmission, and TAVI was ultimately deferred after the diagnosis was confirmed. Prolonged incubation of blood cultures subsequently identified B. quintana, while brain magnetic resonance imaging (MRI) revealed a lesion suspicious for an intracranial infectious aneurysm. Definite IE was established according to the 2023 Duke-International Society for Cardiovascular Infectious Diseases (Duke-ISCVID) criteria based on two major criteria: high-titer Bartonella serology and imaging evidence of a peri-annular abscess. No classical epidemiological risk factors for Bartonella infection were identified. Despite targeted antimicrobial therapy, the patient experienced progressive clinical deterioration, and multiple comorbidities precluded surgical intervention. He ultimately died of multiorgan failure. This case highlights the diagnostic challenge of occult B. quintana IE incidentally identified during pre-TAVI evaluation, including in patients without classical epidemiological risk factors or overt manifestations of infection. It also emphasizes that unexpected peri-annular abnormalities detected during pre-TAVI evaluation should prompt a thorough investigation for IE, even in clinically unsuspected cases, with direct implications for procedural planning.

Human head lice (Pediculus humanus capitis De Geer, 1767) remain a public health concern, largely due to their widespread resistance to commonly used pediculicides. This study assessed genetic diversity and permethrin resistance in head lice collected from individuals in Seville, Spain. A total of 402 lice were sampled, of which 27 specimens were selected for detailed morphological, molecular, and phylogenetic analyses. Molecular characterization based on mitochondrial markers (cox1, cob and 12S) revealed a specific pattern of genetic diversity, identifying two distinct clades (A and B), with low sequence similarity between them, and clade B predominating in the sampled population. Geometric morphometric analyses revealed significant global size differences between clades A and B, with clade B lice being the largest specimens. All analyzed lice carried three mutations (M815I, T917I and L920F) in the voltage-sensitive sodium channel (VSSC) gene, indicating fixation of alleles associated with permethrin resistance. These findings provide preliminary evidence of permethrin resistance-associated mutations in head lice from Seville and underscore the need for larger studies to determine their frequency and epidemiological significance. Moreover, this study represents the first molecular characterization of head lice in this region and supports the combined use of morphometric and molecular approaches to better understand lice diversity and resistance patterns.

Nicotinic acetylcholine receptors (nAChRs) are key mediators of synaptic transmission in invertebrates and major targets of pesticide action. In early life stages of marine Copepoda, such as the parasitic salmon louse (Lepeophtheirus salmonis), the expression dynamics and tissue localization of nAChRs remain poorly characterized. Here, we investigate the expression of nAChR-related transcripts across the life cycle of L. salmonis, and spatial distribution of expression in the early copepodid life stage. Using RNA sequencing of pooled specimens from eleven groups (nauplius I to adults), we identify statistically significant differences in expression patterns. Early sampled developmental groups (nauplius I, nauplius II, copepodids) appear to have higher expression levels of all nAChR subunits compared to older developmental groups (chalimus, pre-adult I, pre-adult II, adult). Comparison with synapsin indicates that these patterns largely correlate with neural tissue abundance. However, specific subunits exhibit distinct stage- and sex-specific expression profiles, suggesting temporal specialization of nicotinic cholinergic signalling. RNA-FISH localization further reveals receptor-specific spatial patterns in the central ganglia, antennae, and near ocular structures in copepodids. Together, these results demonstrate that nAChR expression in L. salmonis is governed by a combination of neural tissue abundance and subunit-specific regulatory dynamics, providing a foundation for understanding nAChR function across salmon lice life stages.

Head lice infestation (pediculosis capitis) remains a prevalent issue among school-aged children globally, with social and economic consequences that extend beyond the medical domain. This study investigates the prevalence of head lice infestation among Greek children before and during the COVID-19 pandemic, examines associated sociodemographic and behavioural factors and explores parental beliefs and treatment practices. A structured online questionnaire capturing self-reported infestation frequency, treatment practices and parental beliefs was completed by 227 parents/guardians of children attending Greek kindergartens and primary schools. Statistical analyses included Wilcoxon signed-rank tests, chi-square tests and Spearman correlations. Self-reported infestation frequency decreased significantly during the pandemic, consistent with reduced interpersonal contact. Manual removal of lice and children's higher social extroversion showed weak associations with more frequent infestation. Parental adherence to recommended treatment use was generally high, although misconceptions-particularly regarding pet transmission and hygiene-persisted. Although self-reported infestation frequency was not high in most households, parental misconceptions may hinder effective prevention and management. Educational interventions targeting these misconceptions could support more evidence-based responses and reduce the social stigma associated with lice infestation in school communities.

Migratory birds host diverse ectoparasites, but molecular information on avian chewing lice from Central Asia remains limited. We characterized ectoparasites recovered from wild birds during spring and autumn migration at the Shakpak Ornithological Station, Kazakhstan, and molecularly characterized selected chewing lice. Field records from 20 April-10 May and 25 September-13 October 2025 were consolidated. Representative lice from four host species were photographically examined, and five selected isolates from a black kite (Milvus migrans), two barn swallows (Hirundo rustica), a European roller (Coracias garrulus), and a European bee-eater (Merops apiaster) underwent PCR amplification, bidirectional Sanger sequencing of a partial mitochondrial cox1 fragment, and phylogenetic analysis. Among 1882 examined birds, 99 ectoparasites were recovered, comprising 88 chewing lice and 11 blood-feeding flies. Because ectoparasite counts were available only as aggregate host-taxon records and were not linked to individual birds, the field data describe specimen recovery only and cannot be used to estimate infestation prevalence, mean abundance, or mean intensity. The five sequenced isolates were tentatively assigned at genus level to Craspedorrhynchus sp. (BL1), Brueelia sp. (BL2-BL3), Capraiella sp. (BL4), and Meropoecus sp. (BL5), with GenBank accessions PZ756682-PZ756686. Photographic morphology was broadly concordant with these genus-level placements, although bootstrap support was modest (54-58%). These findings provide baseline molecular data on migratory-bird chewing lice in Kazakhstan and support expanded individual-host, slide-mounted voucher, and multilocus surveillance.

Human lice can be classified into several mitochondrial clades with distinct geographic distributions, reflecting long-term coevolution with ancient hominids and possibly with human populations. Analysis of ancient lice DNA from archaeological human remains can provide insights into the geographic origins of these clades and the timing of their dispersal. This study analyzes the COI barcode region of lice recovered from the ~1500-year-old salt-preserved mummy (Salt Man 2) at the Chehrabad salt mine in Zanjan Province, Iran. The sequences were compared with those of recent lice from Iran and other regions, available in the GenBank database, to determine clade affiliation and possible historical relationships. Our phylogenetic analysis recovered the five recognized mitochondrial clades (A-E). Ancient lice clustered within clade A but displayed novel haplotypes. Recent nits from Gilan and Kurdistan provinces were grouped within clades A and B, the only clades reported in Iran. The most complete ancient sequence (MLICE005-18) showed close similarity to sequences from Iraq, Pakistan, Egypt, and Iran. These findings, along with future research, could help determine when ancient lice lineages were established or introduced into specific regions. They could also clarify whether they represent haplotypes that have since disappeared or a lineage that still exists in understudied human populations.

Pear psyllids are among the most serious pests of cultivated pear. In the past, repeated misidentifications and the uncritical application of species names led to considerable confusion in biodiversity records and pest monitoring of pear psyllids. Although several revisions clarified many of these issues, misidentifications have persisted, particularly in records attributed to Cacopsylla pyricola (Foerster) in Iran, which may result in serious problems in quarantine and pest management. Currently, 34 species of Cacopsylla are known to be associated with Pyrus spp., five of which are confirmed to occur in Iran, while the occurrence of C. pyricola in the country remains likely but unconfirmed. In this study, we demonstrate that the examined Cacopsylla species differ significantly in their COI barcodes, which can be reliably used for species identification. The COI sequences for C. permixta are published here for the first time. Our results suggest that the GenBank and literature records of C. pyricola from Iran likely represent misidentifications of other species that occur throughout the pear-producing regions of Iran. These misidentifications likely resulted from the application of species names without adequate morphological or molecular confirmation. Our findings highlight the need for careful validation of species records and demonstrate that GenBank sequences should be used cautiously unless they are linked to reliably identified voucher specimens.

The 23 members of the matrix metalloproteinase (MMP) family are involved in a multitude of physiological processes, such as cell migration, invasion, cell signaling, immune response, fibrosis, extracellular matrix remodeling, tissue homeostasis, but also in a broad range of diseases, among which cancer, inflammation (sepsis, arthritis, asthma, chronic obstructive pulmonary disorder), periodontitis, etc. Their biochemical characterization, expression patterns, role as targets, offtargets or antitargets in many physiologic or pathologic conditions made relevant progress over the last decades. MMP inhibitors (MMPIs) belonging to a variety of classes (hydrozamates, carboxylates, thiols, phosphonates, etc.) are well known. The first/second generations such derivatives, all zinc binders, have been investigated in clinical trials as anticancer agents in the late '90s, with poor results, probably due to their metabolic instability, toxicity and lack of selectivity for the target isoform(s). Recent developments in the field saw the design of highly selective inhibitors for several MMPs, belonging to the modified tetracyclines class, as well as mechanism based, suicide inhibitors belonging to the substituted thiiranes class, exosite and allosteric inhibitors which spare the zinc ion from the enzyme active site. Two compounds are in clinical use for the management of periodontitis (doxycycline, at submicrobial dosages) and abametapir for the treatment of lice infestation. Clinical trials in various types of cancer, in different inflammatory conditions, and microbial infections (tuberculosis) with some of the new generation MMPIs are ongoing, and the expected results will demonstrate their efficacy, probably in combination therapy with other drugs. More selective new inhibitors, better planned clinical trials and a better understanding of the biology/pharmacology of these enzymes may lead to other breakthroughs in the field.

Salmon lice (Lepeophtheirus salmonis) cause major welfare issues and economic losses in salmon aquaculture, yet an effective vaccine remains elusive. DNA vaccines are promising but often elicit weak antibody responses in fish. Here, we evaluated different DNA vaccine designs aiming at increasing the immunogenicity of salmon louse immune-modulating labial gland protein 3 (LGP3), including tetrameric tandem repeats to increase the number of epitopes, and fusion or co-delivery with Moritella viscosa flagellin as a molecular adjuvant. Vaccine mRNA expression was detected at the injection site from 3 days until 8 weeks post vaccination (wpv), showing a varied expression among individuals with around 50-80 % of fish expressing antigen transcripts at 8 wpv. Flagellin-encoding constructs induced local inflammation at injection sites and an early upregulation of innate immune genes including tlr5s. Fusion of flagellin to monomeric LGP3 was, however, necessary to induce higher levels of antigen-specific Ig in plasma, whereas co-delivery on separate plasmids did not induce adequate antibody responses. Constructs encoding a tetrameric LGP3 tandem repeat also led to increased antibody levels; co-injection, and especially fusion with the flagellin adjuvant, further amplified this response. Both modifications result in lower but detectable levels of specific antibodies in mucus, showing some correlation to the systemic antibody level in plasma. Increasing the number of epitopes by tetramerization and incorporating flagellin through chimeric constructs, enhanced the immunogenicity of LGP3 in salmon. The results suggest that the applied principles have a broad application for improving DNA vaccine strategies in aquaculture, independent of the specific pathogen targeted.