A preadolescent HIV-positive girl from Southern Africa presented to a public healthcare facility with fever and unilateral facial and neck swelling. Clinical examination revealed generalised lymphadenopathy, hepatosplenomegaly, hypertension and haematuria. A provisional diagnosis of poststreptococcal glomerulonephritis was made; however, when the patient displayed no clinical improvement on supportive treatment, she was referred to a tertiary hospital for further evaluation. The peripheral blood smear showed marked agglutination, which improved on warming. Serum protein electrophoresis demonstrated a monoclonal protein, yet the bone marrow plasmacytosis of 30% was polyclonal and human herpesvirus 8 negative. Subsequently, a lymph node biopsy confirmed a diagnosis of plasmacytic idiopathic multicentric Castleman disease. The atypical presentation contributed to delayed diagnosis and prompted unnecessary invasive investigations in a paediatric patient.

Brucellosis is a multisystem zoonosis that can mimic complicated bacterial infection in children. A 10-year-old girl presented with prolonged high-grade fever, jaundice, abdominal pain, anorexia and weight loss. The initial syndrome was managed empirically as an undifferentiated complicated bacterial illness because enteric fever and a hepatobiliary or intra-abdominal source were considered. CRP was 333.2 mg/L and total/direct bilirubin 7.24/5.21 mg/dL despite only mild aminotransferase elevation; ultrasonography showed hepatomegaly and nonspecific gallbladder-wall edema without biliary dilatation or focal lesions. CRP peaked at 407.1 mg/L and began falling during meropenem-linezolid therapy before Brucella-directed treatment, so biomarker response was not used diagnostically. Re-taking the history revealed daily consumption of unboiled dairy milk for several months. On hospital day 6, doxycycline, rifampicin and gentamicin were started simultaneously, with discontinuation of meropenem and linezolid. Brucella serology was concordant: a laboratory-reported agglutination result labelled B. melitensis was reactive at 1:80 and later EIA showed strongly positive IgM and IgG, but neither test established species identity and culture/PCR confirmation was not obtained. Fever resolved by hospital day 14. At immediate post-treatment follow-up on 8 September 2026, she remained clinically well; weight had increased from 19 to 20 kg, CRP was 1.2 mg/L, total/direct bilirubin 0.8/0.2 mg/dL, AST/ALT 34/43 IU/L and alkaline phosphatase 417 U/L (within a published pediatric reference interval), with renal function within the laboratory reference range. Hemoglobin had improved to 7.8 g/dL with persistent microcytosis, before oral iron supplementation was initiated. The diagnosis is therefore best regarded as serologically supported pediatric brucellosis rather than microbiologically confirmed disease.

Morphological development is a crucial component of early language acquisition. This study examined developmental changes in types and tokens of inflectional morphemes produced among 214 typically developing Kannada-speaking preschool children and their parents. Inflectional use was elicited through a story retelling task and analyzed in child's and parental speech. Results showed developmental increase in both types and tokens of inflectional morphology production in children, indicating that preschool years constitute an important phase of inflectional systems in Kannada, an agglutinative language. Parental inflectional production remained relatively stable across age groups, while only the variety of parental inflections significantly predicted children's output, emphasizing the role of input richness over frequency. Children produced high functional load markers (namely dative case, tense, and person-number-gender agreement), more frequently than optional or irregular forms. Overall, findings support usage-based theories with educational and clinical relevance. These findings, however, warrant future validation across other naturalistic tasks.

In this study, we describe the first documented cases of equine cutaneous leishmaniasis caused by Leishmania (Mundinia) martiniquensis in France and provide clinical and parasitological data relevant for the recognition of this emerging infection in horses. Three horses presenting localized cutaneous lesions were diagnosed with L. martiniquensis infection in different regions of France without spatial or temporal clustering. Lesions were clinically nonspecific and initially compatible with common equine dermatological conditions, including sarcoid-like tumors. Histopathological examination revealed granulomatous dermatitis with intrahistiocytic organisms morphologically consistent with Leishmania amastigotes in all cases. Molecular analysis of formalin-fixed paraffin-embedded tissue confirmed the presence of Leishmania DNA, and sequencing of the ITS1 locus identified L. martiniquensis. Direct agglutination test serology was negative in two horses and strongly positive in one. In one case, parasite isolation was achieved in culture. The disease remained localized in all animals, with spontaneous regression in one case, resolution following surgical excision in another, and complete healing after intralesional treatment with meglumine antimoniate in the third.

Shiga toxin (Stx) is the main virulence factor of enterohemorrhagic Escherichia coli. Between its two types-Stx1 and Stx2-E. coli O157:H7 produces Stx2, which causes more severe infections compared with Stx1 or both Stx1 and Stx2. In this study, we isolated and identified E. coli O157:H7 from frozen raw beef samples and both Stx1 and Stx2 from frozen raw beef liver samples collected from the Al-Riyadh market in Saudi Arabia. Phenotypic detection was conducted using suitable and specific media-sorbitol MacConkey agar and Salmonella chromogenic agar-with E. coli O157:H7 appearing as colorless and blue-colored colonies, respectively. Furthermore, serological testing using DrySpot E. coli O157 latex agglutination tests was conducted to verify the identification and detection results. A conventional polymerase chain reaction was conducted using specific primers of the genes encoding Stx1 and Stx2 for further verification. The results showed that among the 50 frozen raw beef meat samples, 11 colonies harbored the stx2 gene with an amplicon of 420 bp (22%). Meanwhile, among the 50 frozen raw beef liver samples, 5 samples harbored either both the stx1 and stx2 genes or the stx2 gene alone, with amplicons of 310 and 420 bp, respectively (10%), while 6 samples harbored only the stx2 gene (12%). Overall, E. coli O157:H7 containing Stx2 was prevalent in beef meat, while Stx1 and/or Stx2 were identified in beef liver. Furthermore, E. coli O157:H7 harboring stx2 genes were found to be more resistant to different antibiotic classes (50%) than strains containing stx1 and/or stx2 genes (42.28%). Moreover, doubling time in tryptic soy medium extended to 60 min for strains harboring stx2 alone and 55 min for strains harboring stx1 and/or stx2. In conclusion, E. coli O157:H7 was found to be considerably more multidrug resistant than Stx1 and/or Stx2 with respect to several conditions and circumstances.

Mycoplasma synoviae (M. synoviae) is an avian pathogen responsible for respiratory disease and synovitis. The VlhA (variable lipoprotein hemagglutinin) family of surface adhesins plays a critical role in host cell attachment, yet the specific residues and structural determinants governing this interaction remain incompletely understood. In this study, we selected the C-terminal lipid-associated membrane hemagglutinin (LAM HA) domain within the VlhA family as the bait protein, based on its conserved C-terminal region. Yeast two-hybrid screening identified 18 LAM HA-interacting host proteins, and molecular docking pinpointed five residues (S83, R85, Y88, N124, K192) as the most frequent interaction hotspots. To assess their collective functional relevance, we constructed a combined deletion mutant lacking these five candidate residues. At the optimal pH of 6.0-6.5, wild-type LAM HA showed the highest titer (1:2), significantly exceeding that at pH 7.0-7.5 (no activity) and pH 5.0-5.5 (1:1) (p < 0.05), whereas the deletion mutant displayed a reduced titer (from 2 to 1; p = 0.05). Secondary structure analysis at the same pH revealed decreased α-helix content (from 7.90% to 7.57%), along with increased β-sheet (from 38.92% to 38.83%) and random coil (from 10.83% to 10.44%). Molecular dynamics simulations revealed that the deletion mutant exhibited elevated RMSF (from 2.83 ± 1.88 Å to 4.18 ± 2.65 Å) and Rg (from 40.48 ± 1.31 Å to 54.16 ± 4.47 Å) at pH 6.0-6.5, while RMSD showed a slight decrease (11.17 ± 1.33 Å vs. 12.14 ± 0.21 Å), collectively indicating compromised structural stability of the mutant. Collectively, these findings suggest that the LAM HA domain contributes to hemagglutination activity through pH-sensitive conformational stability and specific residue clusters-a property that may be relevant to M. synoviae colonization in the acidic microenvironments of the respiratory tract and synovial fluid during infection.