Rhodococcus equi is a cosmopolitan bacterium found in the feces of several animals, and it is recognized as a major cause of bronchopneumonia in foals, as well as an opportunistic pathogen causing infections in humans and, rarely, in other species. This report describes a rare and atypical infection by Rhodococcus equi in a mixed-breed dog, associated with a pyogranulomatous pleuropneumonia and mediastinitis with abundant intralesional Gram-positive coccobacilli. The bacterium was isolated and identified as Rhodococcus hoagii (R. equi) using matrix-assisted laser desorption ionization-time of flight (MALDI-ToF), followed by whole-genomic sequencing that detected the vapN virulence-associated gene and identified a new sequence type (ST), designated as ST111.

Thoracic splenosis is a well-documented yet clinically elusive sequela of combined splenic rupture and diaphragmatic trauma, classically presenting years after initial injury as unexplained pleural effusions or dark hypervascular pleural nodules. This case illustrates a critical diagnostic pitfall: small superficial forceps biopsies of suspected ectopic splenomas routinely harvest only the reactive fibrous capsule, yielding non-specific inflammatory histology that can obscure unconfirmed thoracic splenosis while requiring careful differentiation from tuberculous pleuritis and pleural malignancy.

Peste des petits ruminants (PPR), sheep and goat pox (SGP), and contagious caprine pleuropneumonia (CCPP) are diseases of small ruminants and are the major constraints to livestock trading in Africa, the Middle East, and Asia. Vaccination against these diseases individually is challenging to veterinary authorities due to high cost and logistics. In this study, we evaluate the safety and immunogenicity of a multivalent vaccine (JOVAC-Combo[®]) in goats in Somalia that induced seroconversion against all three pathogens, PPR, SGP, and CCPP. A total of 120 apparently healthy, seronegative young goats (4-9 months old) from three different villages in Somalia were enrolled (90 vaccinated with JOVAC-Combo[®] and 30 controls) and monitored for evidence of adverse effects and serological response for 90 days post-vaccination. JOVAC-Combo[®] was found to be safe and immunogenic, with no detectable side effects. JOVAC-Combo[®] induced humoral immunity by 14 days post-vaccination; at 30 days post-vaccination, antibody levels were high for all three pathogens, and they remained high until the end of the study (day 90). Whether immunity persists beyond the study period, and whether it translates into protection against clinical disease, remains to be established. These findings present a positive indication for the use of a cost-effective multivalent vaccine for supporting the national and regional efforts to control and reduce impacts of PPR, SGP, and CCPP infections in endemic areas.

The Beijing genotype is the main component of the M. tuberculosis population in Kazakhstan. In this study, we investigated the association of drug resistance (including MDR) and clinical forms of tuberculosis with the Beijing genotype and its dominant clusters, and compared obtained results among new, recurrent and all TB cases. In total, 759 M. tuberculosis isolates were collected from new (n = 540) and recurrent TB cases (n = 219). Drug susceptibility testing was performed on the BACTEC-MGIT 960 system; 24 MIRU-VNTR analysis was carried out to identify M. tuberculosis genotypes. The Beijing genotype was detected in 65.2% (495/759) of all TB cases and was associated with recurrent TB compared with new cases (78% vs. 60%, p < 0.0001). Among both new and recurrent TB cases, the Beijing genotype was associated with drug resistance (p < 0.0001 and p < 0.0001), including MDR (p < 0.0001 and p = 0.0118). Central Asian/Russian cluster 94-32 was the most widespread Beijing cluster in Kazakhstan (52.5%; 260/495). Association of cluster 94-32 with drug-resistant TB in general was confirmed across all cases (p = 0.010) and recurrent TB cases (p = 0.0191; OR = 4.8958; 95%CI: 1.2965-18.4883), while individuals with new TB cases were more likely to be diagnosed with MDR-TB specifically (p = 0.021). Among clinical forms of TB, a significant association was detected between fibrous-cavernous tuberculosis and drug resistance (p = 0.0019; OR = 3.3801; 95%CI: 1.5692-7.2807), including MDR (p = 0.0054; OR = 3.2453; 95%CI: 1.4167-7.4345), among all TB cases. TB patients with Beijing cluster 94-15 mostly had drug-susceptible TB among all TB cases and recurrent cases (p < 0.05). Drug-susceptible tuberculosis was observed among patients with focal TB among new cases (p = 0.0254; OR = 0.1723; 95%CI: 0.0369-0.8050). Tuberculous pleurisy was more commonly diagnosed in individuals with non-Beijing genotypes among all TB cases (p = 0.0430; OR = 0.3643; 95%CI: 0.1371-0.9686). The M. tuberculosis Beijing genotype, particularly the Central Asian cluster 94-32, plays a significant role in the distribution of drug-resistant TB among all TB cases and recurrent cases, including MDR-TB among new TB cases in Kazakhstan. On the contrary, the Beijing cluster 94-15 may contribute to the spread of drug-susceptible TB among all TB cases and recurrent TB cases.

A 90-year-old woman presented with an antibiotic-resistant fever and right-sided pleural effusion. Pleural fluid analysis revealed exudative effusion without identifiable pathogens. Sjögren's disease (SjD) was diagnosed based on anti-SS-A/SS-B antibody positivity and labial salivary gland biopsy findings. Pleural effusion was suspected to be associated with SjD, although a definitive causal relationship could not be established. The timing of SjD onset remained uncertain; however, pleural effusion as the initial manifestation is rare. This represents the oldest reported case in which SjD-associated pleuritis is suspected and is extremely rare in individuals aged ≥90 years.

Rheumatoid arthritis (RA)-related pleural disease is an uncommon but serious extra-articular complication that can closely mimic empyema. Rheumatoid pleural effusions are exudative, with low pH, markedly reduced glucose, and elevated lactate dehydrogenase (LDH), and the fluid may appear green and frankly purulent, a constellation that overlaps substantially with infected parapneumonic effusion, particularly when cultures are negative. We report a 66-year-old woman with a 22-year history of seropositive, erosive, nodular RA who presented with recurrent right-sided pleural effusions and progressive dyspnea over three years. She was initially diagnosed with empyema following a presumed ruptured pleural-based pulmonary abscess. Pleural fluid was an exudate with elevated LDH (1,364 U/L), low glucose (45 mg/dL), and a lipid profile consistent with a chronic pseudochylous effusion, and repeated bacterial, mycobacterial, and fungal cultures were sterile. Video-assisted thoracoscopic surgery (VATS) with pleural and lung biopsies demonstrated findings characteristic of RA-related lung disease, including fibrinous pleuritis, follicular bronchiolitis, and a usual interstitial pneumonia (UIP) pattern. Because the lung remained trapped by a fibrous peel, staged thoracotomy with decortication and parietal pleurectomy was performed, and immunosuppression was escalated from leflunomide to rituximab. Detailed long-term follow-up data were not available for inclusion in this report. This case illustrates that in a patient with established RA, an exudative, culture-negative, purulent-appearing pleural effusion should raise suspicion of rheumatoid pleuritis before empyema. Early recognition, alongside continued exclusion of infection, may reduce diagnostic delay and the need for extensive thoracic surgery.

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease that primarily affects women of reproductive age. The disease may involve extrapulmonary sites, including the lymphatic system, and can present with a lymphocyte-predominant pleural effusion mimicking tuberculosis. We report a 35-year-old woman who presented with a three-year history of progressive dyspnea and recurrent lymphocyte-predominant exudative pleural effusions. She was empirically started on anti-TB therapy at a local hospital but showed no clinical improvement. Upon evaluation at a tertiary center, there was decreased air entry over the posterior third of the chest. Repeat pleural fluid analysis demonstrated a milky appearance with elevated triglyceride levels, consistent with chylous effusion. High-resolution CT showed diffuse, bilateral, thin-walled pulmonary cysts and bilateral pleural effusion with retroperitoneal lymphatic involvement, which confirmed the diagnosis of LAM. Treatment with sirolimus was started and showed significant clinical improvement, but the patient discontinued therapy after two months due to financial constraints. In this patient, LAM presented as tuberculous pleuritis that delayed the definitive diagnosis. This should alert clinicians in high TB burden settings to consider this rare disease in reproductive-aged women who present with progressive dyspnea and a lymphocyte-predominant pleural effusion, particularly when there is no response to anti-TB therapy.

Differentiating tuberculous (TB) pleurisy from malignant pleural mesothelioma is challenging due to similar clinical presentations. We report an 83-year-old man with sarcomatoid mesothelioma initially treated for TB pleurisy. He presented with lymphocyte-predominant exudative pleural effusion and a positive Interferon-Gamma Release Assay. Thoracoscopy revealed purulent effusion, but biopsies were non-diagnostic. Despite empiric anti-tuberculosis therapy, the effusion persisted. A subsequent surgical biopsy showed fibrosis and scattered spindle cells. However, 2 months later, a rapidly growing chest wall mass with bone invasion appeared. A CT-guided percutaneous biopsy showed proliferation of atypical spindle cells and fluorescence in situ hybridization (FISH) analysis allowed for the diagnosis of sarcomatoid mesothelioma. This case highlights the aggressive nature of sarcomatoid mesothelioma and its diagnostic difficulty. For treatment-refractory pleurisy, clinicians must maintain high suspicion, ensuring vigilant follow-up and prompt repeat biopsies despite negative initial results, while consulting pathologists to consider additional FISH testing.