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Изоляция Остерии цуцугамуши от человеческой крови и факторов, оказывающих воздействие на изолацию в Южной Корее.

ВВЕДЕНИЕ: < < Ориентия цуцугамуши > > , побудительный агент скруба тифа, эндемична для Южной Кореи. Хотя широко используются такие методы диагностики, как ПЦР и иммунохроматографические тесты (ИКТ), патогенная изоляция по-прежнему имеет важнейшее значение для антимикробной резистентности и генетических исследований. В ходе этого исследования было собрано 444 пробы крови у пациентов, страдающих фебриллями, в 13 больницах. Из 263 образцов, отнесенных к категории скруба тифа, по крайней мере с помощью одного диагностического метода, 99 изолированных образцов были успешно обработаны. Т

Совпадение в аннотации оригинала
INTRODUCTION: Orientia tsutsugamushi, the causative agent of scrub typhus, is endemic to South Korea. While diagnostics such as PCR and immunochromatographic tests (ICT) are widely used, pathogen isolation remains essential for antimicrobial resistance and genetic studies. METHODS: In this study, 444 blood samples were collected from febrile patients across…

The epidemiology and clinical spectrum of infections of the central nervous system in adults in north India.

Infections of the central nervous system (CNS) are a leading cause of mortality in low- and middle-income countries. We studied the spectrum … cephalitis (13.9%), community-acquired bacterial meningitis (9.7%), cryptococcal meningitis (6.2%), scrub typhus meningoencephalitis (1.7%), neurocysticercosis (1.7%) and fungal brain abscess (1.7%). Human immunodeficiency virus (11.0%) and diabetes mellitus (6.2%) remained the usual predisposing conditions. We found a mortality rate of 27.9%, highest in cases …

Comparison of a conventional and nested PCR for diagnostic confirmation and genotyping of Orientia tsutsugamushi.

A nested polymerase chain reaction (PCR) targeting the 56-kDa antigen gene is currently the most commonly used molecular technique for confirmation of scrub typhus and genotyping of Orientia tsutsugamushi. In this study, we have compared the commonly used nested PCR (N-PCR) with a single-step conventional PCR (C-PCR) for amplification and genotyping. Eschar samples collected from 24 patients with scrub typhus confirmed by IgM enzyme-linked immunosorbent assay were used for DNA extraction following which amplifications were carried out using nested and C-PCR methods. The amplicons were sequence…

In vitro Antagonism between Cefotaxime and Anti-Rickettsial Antibiotics against Orientia tsutsugamushi.

We have investigated the in vitro antimicrobial effects of antibiotic combinations against Orientia tsutsugamushi, the causative agent of scrub typhus. ECV304 cells were infected with the Boryong strain of O. tsutsugamushi and incubated in a medium containing doxycycline (4 µg/mL), azithromycin (0.5 µg/mL), rifampin (4 µg/mL), ciprofloxacin (25 µg/mL), gentamicin (5 µg/mL), cefotaxime (2 µg/mL), or combinations of these agents for 7 days, after which immunofluorescent staining for O. tsutsugamushi was performed. The percentages of infective foci in cultures containing antibiotics compared to t…

Detection of Rickettsia tsutsugamushi by gene amplification using polymerase chain reaction techniques.

Scrub typhus is commonly undiagnosed in endemic areas due, in part, to dependence on retrospective serodiagnosis. Since the etiologic agent, R. tsutsugamushi, will not grow in cell-free systems, a rapid direct-agent detection system such as provided by polymerase chain reaction (PCR) methodology is needed. Genes coding for the variable 56-kDa antigen of R. tsutsugamushi were amplified through 35 cycles using 20-mer oligonucleotide primers and Taq polymerase. Amplification of 1-ng samples of DNA extracted from purified prototype R. tsutsugamushi Karp, Gilliam, and Kato strains was detected by d…

Rickettsial infection presenting as culture-negative meningitis.

Meningitis is an unusual presentation of rickettsial infection. We report a patient who was confirmed by serology to have typhus fever (not scrub), but who presented with the typical findings of culture-negative bacterial meningitis. Neurological manifestations of different types of rickettsial infection are discussed.

Tropical infections in the ICU.

Certain arthropod-borne infections are common in tropical regions because of favorable climatic conditions. Water-borne infections like lept … spirosis and viral hepatitis. Hepatorenal syndrome is seen in leptospirosis, falciparum malaria and scrub typhus. The pulmonary renal syndrome is caused by falciparium malaria, leptospirosis, Hantavirus infection and scrub typhus. Fever with altered mental status is produced by bacterial meningitis, Japanese B encephalitis, cerebral malarial, typhoid encephalo …

Spotted fever group and typhus group rickettsioses in humans, South Korea.

The presence of the nucleic acid of the spotted fever group (SPG) and typhus group (TG) rickettsiae was investigated in 200 serum specimens … uding boutonneuse fever, rickettsialpox, R. felis infection, and Japanese spotted fever, as well as scrub typhus and murine typhus, are occurring in Korea.

Invasion and intracellular growth of Rickettsia tsutsugamushi.

Intracellular multiplication of Rickettsia tsutsugamushi, a causative agent of scrub typhus, was examined by electron microscopy of specimens prepared at various time intervals after infection of in vitro cultured cells. The sequential morphological growth cycle of the microorganism is presented diagrammatically.

Respiratory manifestations of rickettsial disease in tropical Australia; Clinical course and implications for patient management.

BACKGROUND: Rickettsial infections have a global distribution and can cause life-threatening disease. Respiratory symptoms can be a harbinger of a more complicated disease course. However, the clinical associations - and the clinical course - of patients with rickettsial disease and respiratory involvement are incompletely defined. METHODS: This was a retrospective study of all patients with a diagnosis of scrub typhus or Queensland tick typhus (QTT) managed at Cairns Hospital in tropical Australia, between 1st January 1997 and 31st October 2023. We determined the demographic, clinical, radio…

Phylogenetic analysis of 56-kDa type-specific antigen gene of Orientia tsutsugamushi isolates in Taiwan.

Scrub typhus is a rickettsial disease transmitted to humans through the bite of chigger mites infected with Orientia tsutsugamushi, and is an endemic disease in Taiwan. To elucidate the molecular epidemiology of O. tsutsugamushi, the complete open reading frame of the 56-kDa type-specific antigen gene sequence of strains isolated from scrub typhus patients were determined and analyzed. A total of 116 isolates of O. tsutsugamushi were successfully isolated from patients infected in diverse geographic origins including Taiwan and three offshore islets, Kinmen, Matsu, and Penghu between May 2006 …

Orientia tsutsugamushi suppresses the production of inflammatory cytokines induced by its own heat-stable component in murine macrophages.

Orientia tsutsugamushi is a Gram-negative obligate intracellular bacterium, which causes scrub typhus. To understand the pathogenesis of scrub typhus, we have investigated the induction of tumor necrosis alpha (TNF-alpha) and interleukin-6 (IL-6) by O. tsutsugamushi in two murine macrophage cell lines. Both live and heat-killed orientia stimulated the production of cytokines in J774A.1 cells. Polymyxin B does not affect the secretion of cytokines. These together with the fact that the immature macrophage cell line, P388D1, did not produce TNF-alpha when induced by either live or heat-killed O.…

Induction of homologous immune response to Rickettsia tsutsugamushi Boryong with a partial 56-kilodalton recombinant antigen fused with the maltose-binding protein MBP-Bor56.

Although the 56-kDa protein of Rickettsia tsutsugamushi has been presumed to play important roles in generating protective immunity against scrub typhus, studies of this protein have been impeded. We used the recombinant 56-kDa protein of R. tsutsugamushi Boryong fused with the maltose-binding protein of Escherichia coli (MBP-Bor56) to analyze its ability to induce protective immunity in a C3H/HeDub murine model. Intraperitoneal immunization of mice with MBP-Bor56 resulted in an increase in the 50% minimal lethal dose of more than 160 times compared with that for the control mice. Splenic mono…

Molecular epidemiology of Orientia tsutsugamushi from outbreak regions, Madhya Pradesh, central India.

Scrub typhus is a seriously neglected life threatening disease in Asia and the islands of the Pacific and Indian oceans. The causative agent is Orientia tsutsugamushi, an obligate intra-cytosolic bacterium transmitted to vertebrate animals such as human or rodent by larval trombiculid mites (chiggers). Here, we conducted an outbreak investigation in Madhya Pradesh state in central India after sudden upsurge in scrub typhus cases and mortality in humans. Sixty-five live traps were placed for capturing the rodents. The captured rodent species were identified and the samples were subjected to nes…

Neglected rickettsial diseases in Southeast Asia: Twenty-five years of progress in surveillance, diagnostics, and clinical research.

BACKGROUND: Rickettsial diseases, including scrub typhus and murine typhus, are major yet persistently under-recognised causes of acute febrile illness in Southeast Asia. Limited diagnostic capacity, ecological complexity, and non-specific clinical presentation have historically contributed to the underestimation of their burden. METHODS: We synthesised 25 years (2001-2025) of integrated epidemiological, clinical, diagnostic, molecular, ecological, and treatment research conducted across Southeast Asia. Evidence from prospective surveillance, hospital-based cohorts, seroepidemiology, molecula…

Rodent bites in a quadriplegic.

Rodent bites are infrequently reported in the medical literature. A rodent bite usually occurs only to individuals with sensory impairment. Rodent saliva can introduce fatal bacterial infections (rat-bite fever, leptospirosis or scrub typhus). We report a case of rodent bite in a patient suffering from post-traumatic quadriplegia.

Etiology and Diagnostic Predictors of Acute Undifferentiated Febrile Illness in Adult Hospitalized Patients at a Tertiary Care Center.

Background Acute undifferentiated febrile illness (AUFI) presents major diagnostic and therapeutic challenges in tropical regions, particula … ). Targeted diagnostic assays were performed for dengue, malaria, leptospirosis, enteric fever, and scrub typhus. Univariate analyses were used to identify clinical and laboratory predictors of specific etiologies, and effect measures were reported where applicable. Results Of the 262 AUFI cases, an etiologic diagnosis was not established in 112 (42.7%) cases. …

Eco-epidemiology of rodent-associated trombiculid mites and infection with Orientia spp. in Southern Chile.

BACKGROUND: Scrub typhus is a potentially severe infection caused by bacteria of the genus Orientia, endemic in Asia-Pacific and recently discovered in southern Chile. The presented study aimed to determine the prevalence and species richness of rodent-associated trombiculid mites and their infection with Orientia spp. in different areas of two regions in southern Chile. METHODOLOGY/PRINCIPAL FINDINGS: During summer 2020, trombiculid mites were collected from rodents captured in three areas in southern Chile known to be endemic for scrub typhus (Cochamó and Chiloé Island in the Los Lagos Regi…

Changing Spectrum of Acute Encephalitis Syndrome in India and a Syndromic Approach.

Acute encephalitis syndrome (AES) refers to an acute onset of fever and clinical neurological manifestation that includes mental confusion, … lex encephalitis (HSE), Japanese encephalitis (JE), and West Nile encephalitis (WNE)] and systemic (scrub typhus, malaria, dengue, and Chikungunya) helps in rational utilization of diagnostic and management resources. In neurological AES, cranial CT/MRI revealing frontotemporal lesion is consistent with HSE, and thalamic and basal ganglia lesions are consisten …

Diagnostic tools used in the evaluation of acute febrile illness in South India: a scoping review.

BACKGROUND: Acute febrile illness (AFI) is characterized by malaise, myalgia and a raised temperature that is a nonspecific manifestation of … udies evaluating possible causes of AFI, 96% tested for malaria followed by 80% for dengue, 72% for scrub typhus, 68% for typhoid and 60% for leptospirosis identifying these as commonly suspected causes of AFI. 54% studies diagnosed malaria with smear microscopy while others diagnosed dengue, scrub typhus, typhoid and leptospirosis using antibody or antigen de …