1
|
Srivastava P, Shukla A, Singh R, Kant R, Mishra N, Behera SP, Dwivedi GR, Yadav DK. Orientia tsutsugamushi: An Unusual Intracellular Bacteria-Adaptation Strategies, Available Antibiotics, and Alternatives for Treatment. Curr Microbiol 2024; 81:236. [PMID: 38907107 DOI: 10.1007/s00284-024-03754-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 05/28/2024] [Indexed: 06/23/2024]
Abstract
During evolution Orientia tsutsugamushi became a smarter obligate bacterium to establish as intracellular pathogens. O. tsutsugamushi is a human pathogenic bacterium responsible for 1 billion infections of scrub typhus. Several novel mechanisms make this bacterium unique (cell wall, genetic constitutions, secretion system, etc.). In 2007, O. tsutsugamushi Boryong was pioneer strain for whole-genome sequencing. But the fundamental biology of this bacterial cell is a mystery till date. The unusual biology makes this organism as model for host cell interaction. Only a few antibiotics are effective against this intracellular pathogen but emergence of less susceptibility toward antibiotics make the situation alarming. The review was captivated to highlight the unusual aspects of adaptation, antibiotics, and drugs beyond antibiotics.
Collapse
Affiliation(s)
- Prashansha Srivastava
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Aishwarya Shukla
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajeev Singh
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajni Kant
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Nalini Mishra
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Sthita P Behera
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Gaurav R Dwivedi
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India.
| | - Dharmendra K Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro 191, Yeonsu-Gu, Incheon, 21924, Korea
| |
Collapse
|
2
|
Jian H, Yang QX, Duan JX, Lai SY, Che GL, Teng J, Chang L, Liu XJ, Luo LL, Liu F. mNGS helped diagnose scrub typhus-associated HLH in children: a report of two cases. Front Public Health 2024; 12:1321123. [PMID: 38784570 PMCID: PMC11111966 DOI: 10.3389/fpubh.2024.1321123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 04/19/2024] [Indexed: 05/25/2024] Open
Abstract
Background Scrub typhus, caused by the Orientia tsutsugamushi (Ot), is a widespread vector-borne disease transmitted by chigger mites. Hemophagocytic lymphohistiocytosis (HLH) is considered to be one of the potentially severe complications. The diagnosis of scrub typhus-associated HLH may be overlooked due to the non-specific clinical characteristics and the absence of pathognomonic eschar. Case presentation We obtained clinical data from two patients in the South of Sichuan, China. The first case involved a 6-year-old girl who exhibited an unexplained fever and was initially diagnosed with sepsis, HLH, and pulmonary infection. The other patient presented a more severe condition characterized by multiple organ dysfunction and was initially diagnosed with septic shock, sepsis, HLH, acute kidney injury (AKI), and pulmonary infection. At first, a specific examination for scrub typhus was not performed due to the absence of a characteristic eschar. Conventional peripheral blood cultures yielded negative results in both patients, and neither of them responded to routine antibiotics. Fortunately, the causative pathogen Orientia tsutsugamushi (Ot) was detected in the plasma samples of both patients using metagenomics next-generation sequencing (mNGS) and further confirmed by polymerase chain reaction. Subsequently, they both were treated with doxycycline and recovered quickly. Conclusion The unbiased mNGS provided a clinically actionable diagnosis for an uncommon pathogen-associated infectious disease that had previously evaded conventional diagnostic approaches.
Collapse
Affiliation(s)
- Hui Jian
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Qiu-xia Yang
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Jia-xin Duan
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Shu-yu Lai
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Guang-lu Che
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Jie Teng
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Li Chang
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Xiao-juan Liu
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| | - Li-li Luo
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
- Department of Pediatric Critical Care Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Fang Liu
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, China
| |
Collapse
|
3
|
Han S, Yang S, Wang Y, Xu Y. Case Report: Encephalitis with Initial Manifestation of Orientia Tsutsugamushi Infection Detected by Metagenomic Next-Generation Sequencing. Infect Drug Resist 2024; 17:749-760. [PMID: 38433784 PMCID: PMC10906725 DOI: 10.2147/idr.s450693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/07/2024] [Indexed: 03/05/2024] Open
Abstract
Purpose Scrub typhus, caused by Orientia tsutsugamushi, is characterized by fever, eschars, lymphadenopathy, and rash. The absence of eschars in some cases makes it difficult to distinguish it from other diseases, complicating the diagnosis process. Atypical Scrub typhus is difficult to diagnose and often leads to delayed treatment. Therefore, early diagnosis and treatment through effective detection methods have high clinical value. Here, a case of scrub typhus with encephalitis symptoms is reported. Patients and Methods A 64-year-old man and mNGS testing. Results A 64-year-old man developed cough, headache, and fever, dismissing it as a respiratory tract infection. Initial treatment with cephalosporin antibiotics had minimal effect. Admission to the respiratory department showed inflammation in blood tests. Subsequent CT and further treatment provided no improvement. Multidisciplinary discussions and neurology department guidance were conducted to consider the suspected diagnosis of encephalitis in the patient. After improving the mNGS detection, the patient was diagnosed with "Orientia tsutsugamushi encephalitis". After treatment with doxycycline, the patient's symptoms were alleviated. He remained afebrile in follow-up and adhered well to medical advice. Conclusion Our case demonstrates that it is difficult to distinguish Orientia tsutsugamushi encephalitis from central nervous system infectious diseases such as meningitis and encephalitis using conventional diagnostic methods, which may affect the treatment plan for the disease. mNGS is a useful and valuable method for early diagnosis of scrub typhus.
Collapse
Affiliation(s)
- Song Han
- The Second Hospital of Shandong University, Cheeloo College of Medicine of Shandong University, Shandong University, Jinan, 250033, People’s Republic of China
| | - Suge Yang
- The Second Hospital of Shandong University, Cheeloo College of Medicine of Shandong University, Shandong University, Jinan, 250033, People’s Republic of China
| | - Yun Wang
- Department of Neurology Medicine, The Second Hospital of Shandong University, Cheeloo College of Medicine of Shandong University, Shandong University, Jinan, 250033, People’s Republic of China
| | - Yingying Xu
- Department of Neurology Medicine, The Second Hospital of Shandong University, Cheeloo College of Medicine of Shandong University, Shandong University, Jinan, 250033, People’s Republic of China
| |
Collapse
|
4
|
Yang X, Zhang L, Chen S, Chen W, Zhang Y, Zhang Y, Liang J, Lv Y, Wang W, Zhou Y, Huang R, Pan D, Li X, Li Q. A case of neonatal tsutsugamushi disease diagnosed with the aid of rickettsial macrogenomic detection. BMC Pediatr 2024; 24:90. [PMID: 38302958 PMCID: PMC10835854 DOI: 10.1186/s12887-024-04561-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/12/2024] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND Tsutsugamushi, also known as bush typhus, is a naturally occurring disease caused by Orientia tsutsugamushi. We reported a case of vertical mother-to-newborn transmission of Orientia tsutsugamushi infection in a newborn from Yunnan (China). CASE PRESENTATION Decreased fetal movements were observed at 39 weeks of gestation. After birth, the newborn (female) had recurrent fever, shortness of breath, and bruising around the mouth and extremities. At 5 h 58 min of age, the newborn was admitted for fever, shortness of breath and generalized rash. The liver was palpable 3 cm below the costal margin, and the limbs showed pitting edema. There was subcutaneous bleeding. Investigations suggested heavy infection, myocardial damage, decreased platelets. Treatment with cefotaxime and ampicillin failed. The mother was hospitalized at 29 weeks of gestation with a fever for 4 consecutive days, and an ulcerated crust was found in the popliteal fossa. Due to this pregnancy history, A diagnosis of Orientia tsutsugamushi infection was suspected in our index case and confirmed by macrogenomic testing and she was treated with vancomycin and meropenem, and later azithromycin for 1 week. The newborn was discharged in good general condition, gradually normalizing body temperature, and decreasing rash and jaundice. There were no abnormalities on subsequent blood macrogenomic tests for the baby. And one month later she showed good mental health, sleep, and food intake and no fever, rash, or jaundice. CONCLUSION Determining the cause of symptoms is the key to treating diseases, especially the rare diseases that can be misdiagnosed. SUITABLE FOR PEOPLE WITH Infectious Diseases; Neonatology; Obstetrics.
Collapse
Affiliation(s)
- Xu Yang
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China.
| | - Ling Zhang
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Shanping Chen
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Wei Chen
- Department of Infectious Diseases, Pu'er People's Hospital, Pu'er, 665000, China
| | - Yushan Zhang
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Yi Zhang
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Jialong Liang
- General Practice, Pu'er People's Hospital, Pu'er, 665000, China
| | - Ying Lv
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Weiyan Wang
- Department of Anesthesiology, Pu'er People's Hospital, Pu'er, 665000, China
| | - Yini Zhou
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Rui Huang
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Dongju Pan
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Xueyu Li
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| | - Qiurong Li
- Department of Paediatrics, Pu'er People's Hospital, Pu'er, 665000, China
| |
Collapse
|
5
|
Wang J, Luo M, Li T, Liu Y, Jiang G, Wu Y, Liu Q, Gong Z, Sun J. The ecological and etiological investigation of ticks and rodents in China: results from an ongoing surveillance study in Zhejiang Province. Front Vet Sci 2023; 10:1268440. [PMID: 38089699 PMCID: PMC10715276 DOI: 10.3389/fvets.2023.1268440] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/13/2023] [Indexed: 05/07/2024] Open
Abstract
OBJECTIVES This study aimed to analyze the population density of vector ticks and reservoir hosts rodents, and to investigate the relevant pathogen infection in Zhejiang Province, China. METHODS In this surveillance study, the data of ticks density were collected with the tick picking method on animal body surface and the drag-flag method, while the rodent density with the night trapping method. The samples of ticks were examined for the severe fever with thrombocytopenia syndrome virus (SFTSV), and blood serum and organs from rodents were subjected for SFTSV, hantavirus, Leptospira, Orientia tsutsugamushi (O. tsutsugamushi) and Yersinia pestis (Y. pestis) screening in the laboratory. RESULTS From 2017 to 2022 in Zhejiang Province, 16,230 parasitic ticks were found in 1848 positive animals, with the density of parasitic ticks of 1.29 ticks per host animal, and a total of 5,201 questing ticks were captured from 1,140,910 meters of vegetation distance with the questing tick density of 0.46 ticks/flag·100 m. Haemaphysalis longicornis (H. longicornis) was the major species. A total of 2,187,739 mousetraps were distributed and 12,705 rodents were trapped, with the density of 0.58 per 100 trap-nights. Rattus norvegicus was the major species. For SFTSV screening, two groups nymphal ticks of H. longicornis were tested to be positive. For the rodents samples, the Leptospira had a positive rate of 12.28% (197/1604), the hantavirus was 1.00% (16/1604), and the O. tsutsugamushi was 0.15% (2/1332). No positive results were found with SFTSV and Y. pestis in the rodents samples. CONCLUSION Findings from this study indicated that the ticks and rodents were widely distributed in Zhejiang Province. Particularly, the positive detection of SFTSV, Leptospira, hantavirus and O. tsutsugamushi in ticks or rodents from this area suggested that more attention should be paid to the possibilities of relevant vector-borne diseases occurrence.
Collapse
Affiliation(s)
- Jinna Wang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Mingyu Luo
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Tianqi Li
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Ying Liu
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Guoqin Jiang
- Shaoxing Center for Disease Control and Prevention, Shaoxing, China
| | - Yuyan Wu
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Qinmei Liu
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Zhenyu Gong
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Jimin Sun
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| |
Collapse
|
6
|
Panda S, Swain SK, Sahu BP, Sarangi R. Insights into genome plasticity and gene regulation in Orientia tsutsugamushi through genome-wide mining of microsatellite markers. 3 Biotech 2023; 13:366. [PMID: 37840877 PMCID: PMC10575825 DOI: 10.1007/s13205-023-03795-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 09/25/2023] [Indexed: 10/17/2023] Open
Abstract
Microsatellite markers are being used for molecular identification and characterization as well as estimation of evolution patterns due to their highly polymorphic nature. The repeats hold 40% of the entire genome of Orientia tsutsugamushi (OT), but not yet been characterized. Thus, we investigated the genome-wide presence of microsatellites within nine complete genomes of OT and analyzed their distribution pattern, composition, and complexity. The in-silico study revealed that the genome of OT enriched with microsatellites having a total of 126,187 SSRs and 10,374 cSSRs throughout the genome, of which 70% and 30% are represented within the coding and non-coding regions, respectively. The relative density (RD) and relative abundance (RA) of SSRs were 42-44.43/kb and 6.25-6.59/kb, while for cSSRs this value ranged from 7.06 to 8.1/kb and 0.50 to 0.55/kb, respectively. However, RA and RD were weakly correlated with genome size and incidence of microsatellites. The mononucleotide repeats (54.55%) were prevalent over di- (33.22%), tri- (11.88%), tetra- (0.27%), penta- (0.02%), hexanucleotide (0.04%) repeats, with poly (A/T) richness over poly (G/C). The motif composition of cSSRs revealed that maximum cSSRs were made up of two microsatellites having unique duplication patterns such as AT-x-AT and CG-x-CG. To our knowledge, this is the first study of microsatellites in the OT genome, where characterization of such variations in repeat sequences would be important in deciphering the origin, rate of mutation, and role of repeat sequences in the genome. More numbers of microsatellites represented within the coding region provide an insight into the genome plasticity that may interfere with gene regulation to mitigate host-pathogen interaction and evolution of the species.
Collapse
Affiliation(s)
- Subhasmita Panda
- Department of Pediatrics, IMS and SUM Hospital, Siksha ‘O’ Anusandhan (Deemed to be University), K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Subrat Kumar Swain
- Medical Research Laboratory, IMS and SUM Hospital, Siksha ‘O’ Anusandhan (Deemed to be University), K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Basanta Pravas Sahu
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Rachita Sarangi
- Department of Pediatrics, IMS and SUM Hospital, Siksha “O” Anusandhan (Deemed to be University), K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| |
Collapse
|
7
|
Harpring M, Cox JV. Plasticity in the cell division processes of obligate intracellular bacteria. Front Cell Infect Microbiol 2023; 13:1205488. [PMID: 37876871 PMCID: PMC10591338 DOI: 10.3389/fcimb.2023.1205488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 09/07/2023] [Indexed: 10/26/2023] Open
Abstract
Most bacteria divide through a highly conserved process called binary fission, in which there is symmetric growth of daughter cells and the synthesis of peptidoglycan at the mid-cell to enable cytokinesis. During this process, the parental cell replicates its chromosomal DNA and segregates replicated chromosomes into the daughter cells. The mechanisms that regulate binary fission have been extensively studied in several model organisms, including Eschericia coli, Bacillus subtilis, and Caulobacter crescentus. These analyses have revealed that a multi-protein complex called the divisome forms at the mid-cell to enable peptidoglycan synthesis and septation during division. In addition, rod-shaped bacteria form a multi-protein complex called the elongasome that drives sidewall peptidoglycan synthesis necessary for the maintenance of rod shape and the lengthening of the cell prior to division. In adapting to their intracellular niche, the obligate intracellular bacteria discussed here have eliminated one to several of the divisome gene products essential for binary fission in E. coli. In addition, genes that encode components of the elongasome, which were mostly lost as rod-shaped bacteria evolved into coccoid organisms, have been retained during the reductive evolutionary process that some coccoid obligate intracellular bacteria have undergone. Although the precise molecular mechanisms that regulate the division of obligate intracellular bacteria remain undefined, the studies summarized here indicate that obligate intracellular bacteria exhibit remarkable plasticity in their cell division processes.
Collapse
Affiliation(s)
| | - John V. Cox
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| |
Collapse
|
8
|
Fromm L, Mehl J, Keller C. Orientia tsutsugamushi: A life between escapes. Microbiologyopen 2023; 12:e1380. [PMID: 37877457 PMCID: PMC10493369 DOI: 10.1002/mbo3.1380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 08/31/2023] [Indexed: 10/26/2023] Open
Abstract
The life cycle of the mite-borne, obligate intracellular pathogen Orientia tsutsugamushi (Ot), the causative agent of human scrub typhus, differs in many aspects from that of other members of the Rickettsiales order. Particularly, the nonlytic cellular exit of individual Ot bacteria at the plasma membrane closely resembles the budding of enveloped viruses but has only been rudimentarily studied at the molecular level. This brief article is focused on the current state of knowledge of escape events in the life cycle of Ot and highlights differences in strategies of other rickettsiae.
Collapse
Affiliation(s)
- Lea Fromm
- Institute of VirologyPhilipps University MarburgMarburgGermany
| | - Jonas Mehl
- Institute of VirologyPhilipps University MarburgMarburgGermany
| | | |
Collapse
|
9
|
Song X, Xie S, Huang X, Chen Z. The diagnosis and treatment of scrub typhus should be emphasized in non-endemic areas: A retrospective case series study. Medicine (Baltimore) 2023; 102:e32988. [PMID: 36827009 PMCID: PMC11309664 DOI: 10.1097/md.0000000000032988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/15/2023] [Accepted: 01/26/2023] [Indexed: 02/25/2023] Open
Abstract
The morbidity of tsutsugamushi is increasing and is no longer limited to endemic areas. Delayed diagnosis and inappropriate treatment can cause severe complications and increase mortality rates. We conducted a retrospective case series of patients with scrub typhus at our institution to report our experience and discuss the diagnostic modalities. We encountered 21 cases of scrub typhus at our institution between 2014 and 2022. The average age of the patients was 52 years (range: 22-63 years), 11 (52%) were farmers, and 11 (52%) had clear outdoor activities. Twenty (95%) patients had an ineffective history of general antibiotic treatment. The classic presentation was repeated fever in 95% of patients. Seventeen patients (81%) had eschar mainly on the groin (35%) and armpit (35%). Common laboratory findings included eosinophilia (95%), elevated alanine aminotransferase (95%), elevated aspartate aminotransferase (86%), thrombocytopenia (76%), lower hemoglobin (71%), and neutrophilia (38%). Six (29%) patients received the treatment of tigecycline, 4 (19%) patients received the treatment of doxycycline, and 11 (52%) patients received the treatment of minocycline. After 3 days of specific treatment, the eosinophilic levels showed a recovery trend. Twenty (95%) patients fully recovered, and 1 (5%) died. Careful physical examination and medical history are important for the early diagnosis of scrub typhus; clinicians in non-endemic areas need to strengthen their understanding of scrub typhus.
Collapse
Affiliation(s)
- Xin Song
- Medical Department of Nanchang University, Nanchang, Jiangxi, China
- Department of Emergency, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, China
| | - Shu Xie
- Department of Emergency, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, China
- The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, China
| | - Xinhui Huang
- Medical Department of Nanchang University, Nanchang, Jiangxi, China
- Department of Emergency, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, China
| | - Zhi Chen
- Department of Emergency, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, China
- The First Affiliated Hospital of Nanchang Medical College, Nanchang, Jiangxi, China
| |
Collapse
|
10
|
Wolbachia Promotes Its Own Uptake by Host Cells. Infect Immun 2023; 91:e0055722. [PMID: 36648231 PMCID: PMC9933726 DOI: 10.1128/iai.00557-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Wolbachia pipientis is an incredibly widespread bacterial symbiont of insects, present in an estimated 25 to 52% of species worldwide. Wolbachia is faithfully maternally transmitted both in a laboratory setting and in the wild. In an established infection, Wolbachia is primarily intracellular, residing within host-derived vacuoles that are associated with the endoplasmic reticulum. However, Wolbachia also frequently transfers between host species, requiring an extracellular stage to its life cycle. Indeed, Wolbachia has been moved between insect species for the precise goal of controlling populations. The use of Wolbachia in this application requires that we better understand how it initiates and establishes new infections. Here, we designed a novel method for live tracking Wolbachia cells during infection using a combination of stains and microscopy. We show that live Wolbachia cells are taken up by host cells at a much faster rate than dead Wolbachia cells, indicating that Wolbachia bacteria play a role in their own uptake and that Wolbachia colonization is not just a passive process. We also show that the host actin cytoskeleton must be intact for this to occur and that drugs that disrupt the actin cytoskeleton effectively abrogate Wolbachia uptake. The development of this live infection assay will assist in future efforts to characterize Wolbachia factors used during host infection.
Collapse
|
11
|
Dey RK, Imad HA, Aung PL, Faisham M, Moosa M, Hasna M, Afaa A, Ngamprasertchai T, Matsee W, Nguitragool W, Nakayama EE, Shioda T. Concurrent Infection with SARS-CoV-2 and Orientia tsutsugamushi during the COVID-19 Pandemic in the Maldives. Trop Med Infect Dis 2023; 8:tropicalmed8020082. [PMID: 36828498 PMCID: PMC9959419 DOI: 10.3390/tropicalmed8020082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 01/27/2023] Open
Abstract
The COVID-19 pandemic was the worst public-health crisis in recent history. The impact of the pandemic in tropical regions was further complicated by other endemic tropical diseases, which can cause concurrent infections along with COVID-19. Here, we describe the clinical course of a patient with concurrent COVID-19 and scrub typhus infection. The patient's de-identified clinical data were retrieved retrospectively. The patient had progressive breathlessness at the time of presentation and was hospitalized for COVID-19. Respiratory examination revealed dyspnea, tachypnea, and coarse crepitations bilaterally over the entire lung field. Oxygenation was impaired, and a PaO2/FiO2 ratio of 229 suggested acute respiratory distress syndrome. Laboratory tests indicated leukocytosis, thrombocytopenia, ferritinemia, hypoalbuminemia, and transaminitis. Upon revaluation for persistent fever, physical examination revealed an eschar in the right antecubital fossa. Serology further confirmed scrub typhus, with IgM and IgG antibody positivity. A remarkable clinical recovery was achieved with doxycycline. The COVID-19 pandemic might have masked endemic tropical diseases. Clinicians working in endemic regions must always consider common tropical diseases that may present as a co-infection, as in our case. Travel and exposure history are critical guides for narrowing down a differential diagnosis. Early diagnosis and treatment can prevent complications.
Collapse
Affiliation(s)
- Rajib Kumar Dey
- Department of Medicine, Indira Gandhi Memorial Hospital, Malé 20002, Maldives
| | - Hisham Ahmed Imad
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Thai Travel Clinic, Hospital for Tropical Diseases, Bangkok 10400, Thailand
- Center for Infectious Disease Education and Research, Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
- Correspondence: or
| | - Pyae Linn Aung
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Mohamed Faisham
- Department of Medicine, Indira Gandhi Memorial Hospital, Malé 20002, Maldives
| | - Muaz Moosa
- Department of Medicine, Indira Gandhi Memorial Hospital, Malé 20002, Maldives
| | - Mariyam Hasna
- Department of Medicine, Indira Gandhi Memorial Hospital, Malé 20002, Maldives
| | - Aminath Afaa
- Department of Medicine, Indira Gandhi Memorial Hospital, Malé 20002, Maldives
| | - Thundon Ngamprasertchai
- Thai Travel Clinic, Hospital for Tropical Diseases, Bangkok 10400, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Wasin Matsee
- Thai Travel Clinic, Hospital for Tropical Diseases, Bangkok 10400, Thailand
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Wang Nguitragool
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Emi E. Nakayama
- Center for Infectious Disease Education and Research, Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Tatsuo Shioda
- Center for Infectious Disease Education and Research, Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| |
Collapse
|
12
|
Fisher J, Gonzales C, Chroust Z, Liang Y, Soong L. Orientia tsutsugamushi Infection Stimulates Syk-Dependent Responses and Innate Cytosolic Defenses in Macrophages. Pathogens 2022; 12:pathogens12010053. [PMID: 36678402 PMCID: PMC9861896 DOI: 10.3390/pathogens12010053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/12/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
Orientia tsutsugamushi is an obligately intracellular bacterium and an etiological agent of scrub typhus. Human studies and animal models of scrub typhus have shown robust type 1-skewed proinflammatory responses during severe infection. Macrophages (MΦ) play a critical role in initiating such responses, yet mechanisms of innate recognition for O. tsutsugamushi remain unclear. In this study, we investigated whether Syk-dependent C-type lectin receptors (CLRs) contribute to innate immune recognition and the generation of proinflammatory responses. To validate the role of CLRs in scrub typhus, we infected murine bone marrow-derived MΦ with O. tsutsugamushi in the presence of selective Syk inhibitors and analyzed a panel of CLRs and proinflammatory markers via qRT-PCR. We found that Mincle/Clec4a and Clec5a transcription was significantly abrogated upon Syk inhibition at 6 h of infection. The effect of Syk inhibition on Mincle protein expression was validated via Western blot. Syk-inhibited MΦ had diminished expression of type 1 cytokines/chemokines (Il12p40, Tnf, Il27p28, Cxcl1) during infection. Additionally, expression of innate immune cytosolic sensors (Mx1 and Oas1-3) was highly induced in the brain of lethally infected mice. We established that Mx1 and Oas1 expression was reduced in Syk-inhibited MΦ, while Oas2, Oas3, and MerTK were not sensitive to Syk inhibition. This study reveals that Syk-dependent CLRs contribute to inflammatory responses against O. tsutsugamushi. It also provides the first evidence for Syk-dependent activation of intracellular defenses during infection, suggesting a role of pattern recognition receptor crosstalk in orchestrating macrophage-mediated responses to this poorly studied bacterium.
Collapse
Affiliation(s)
- James Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- School of Medicine, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Casey Gonzales
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Zachary Chroust
- School of Medicine, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | - Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- Correspondence: (Y.L.); (L.S.)
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
- Correspondence: (Y.L.); (L.S.)
| |
Collapse
|
13
|
Liang Y, Wang H, Gonzales C, Thiriot J, Sunyakumthorn P, Melby PC, Sun J, Soong L. CCR7/dendritic cell axis mediates early bacterial dissemination in Orientia tsutsugamushi-infected mice. Front Immunol 2022; 13:1061031. [PMID: 36618364 PMCID: PMC9813216 DOI: 10.3389/fimmu.2022.1061031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022] Open
Abstract
Scrub typhus is a life-threatening zoonosis caused by the obligate intracellular bacterium Orientia tsutsugamushi (Ot) that is transmitted by the infected larvae of trombiculid mites. However, the mechanism by which Ot disseminates from the bite site to visceral organs remains unclear; host innate immunity against bacterial dissemination and replication during early infection is poorly understood. In this study, by using an intradermal infection mouse model and fluorescent probe-labeled Ot, we assessed the dynamic pattern of innate immune cell responses at the inoculation site. We found that neutrophils were the first responders to Ot infection and migrated into the skin for bacterial uptake. Ot infection greatly induced neutrophil activation, and Ot-neutrophil interaction remarkably promoted cell death both in vitro and in vivo. Depletion of neutrophils did not alter bacterial dissemination in mice, as evidenced by similar bacterial burdens in the skin and draining lymph nodes (dLN) at day 3, as well as in the lungs and brains at day 14, as compared to the control mice. Instead, dendritic cells (DCs) and macrophages played a role as a Trojan horse and transmitted Ot from the skin into dLN. Importantly, the absence of homing receptor CCR7 or neutralization of its ligand, CCL21, significantly impaired DC migration, resulting in reduced bacterial burdens in dLN. Taken together, our study sheds light on a CCR7/dendritic cell-mediated mechanism of early Ot dissemination and provides new insights into therapeutic and vaccine development strategies for scrub typhus.
Collapse
Affiliation(s)
- Yuejin Liang
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
| | - Hui Wang
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Casey Gonzales
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Joseph Thiriot
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Piyanate Sunyakumthorn
- Department of Veterinary Medicine, United States Army Medical Directorate, Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok, Thailand
| | - Peter C. Melby
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, United States
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| |
Collapse
|
14
|
Sharma S, Adhikari A, Ghimire N, Mainali G, Yadav SK, Pudasaini P, Neupane S. Hemophagocytic
Lymphohistiocytosis
secondary to Rickettsial infection: A case report. Clin Case Rep 2022; 10:e6730. [PMCID: PMC9744712 DOI: 10.1002/ccr3.6730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 11/11/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022] Open
Affiliation(s)
- Shriya Sharma
- Nepalese Army Institute of Health Sciences Kathmandu Nepal
| | | | - Nirmal Ghimire
- Department of Internal Medicine Nepal Police Hospital Kathmandu Nepal
| | - Gaurab Mainali
- Nepalese Army Institute of Health Sciences Kathmandu Nepal
| | - Sumit Kumar Yadav
- Department of Internal Medicine Shree Birendra Hospital Kathmandu Nepal
| | | | | |
Collapse
|
15
|
Bhandari M, Singh RK, Laishevtcev A, Mohapatra TM, Nigam M, Mori E, Vasconcelos de Lacerda BCG, Coutinho HDM, Mishra AP. Revisiting scrub typhus: A neglected tropical disease. Comp Immunol Microbiol Infect Dis 2022; 90-91:101888. [PMID: 36252451 DOI: 10.1016/j.cimid.2022.101888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/18/2022] [Accepted: 09/29/2022] [Indexed: 02/08/2023]
Abstract
Scrub typhus is an under diagnosed re-emerging vector borne disease caused by an intracellular gram negative bacteria, Orientia. The disease is commonly prevalent in rural and hilly areas of Tsutsugumashi triangle. The diagnosis of the disease is very challenging due to similarity of its early symptoms with other febrile illnesses, like dengue and COVID 19, as well as non-availability of rapid, reliable and cost-effective methods. Moreover, the diverse clinical presentation in severe cases make it significant health problem. The occupational and behavioral risks responsible for the transmission lead to urgent need of vaccine development against the disease. The complete knowledge about its pathogenesis and the interaction with host's immune cells may help the scientists in developing the appropriate diagnostic methods as well as the vaccines.
Collapse
Affiliation(s)
- Munni Bhandari
- Department of Microbiology, School of Life Sciences, Hemvati Nandan Bahuguna Garhwal University, Srinagar (Garhwal) 246174, India.
| | - Rahul Kunwar Singh
- Department of Microbiology, School of Life Sciences, Hemvati Nandan Bahuguna Garhwal University, Srinagar (Garhwal) 246174, India.
| | - Alexey Laishevtcev
- Federal Research Center - All-Russian Scientific Research Institute of Experimental Veterinary Medicine named after K.I. Skryabin and Y.R. Kovalenko of the Russian Academy of Sciences, Moscow, Russia; Laboratory of Biocontrol and Antimicrobial Resistance, Orel State, University Named After I.S. Turgenev, Orel, Russia.
| | - Tribhuvan Mohan Mohapatra
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
| | - Manisha Nigam
- Department of Biochemistry, Hemvati Nandan Bahuguna Garhwal University, Srinagar Garhwal-246174, Uttarakhand, India.
| | - Edna Mori
- CECAPE - College of Dentistry, Av. Padre Cícero, 3917, Juazeiro do Norte, São José CE 63024-015, Brazil.
| | | | | | - Abhay Prakash Mishra
- Department of Pharmacology, Faculty of Health Science, University of Free State, Bloemfontein 9300, South Africa.
| |
Collapse
|
16
|
Panda S, Swain SK, Sahu BP, Sarangi R. Gene expression and involvement of signaling pathways during host-pathogen interplay in Orientia tsutsugamushi infection. 3 Biotech 2022; 12:180. [PMID: 35860421 PMCID: PMC9295102 DOI: 10.1007/s13205-022-03239-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/18/2022] [Indexed: 11/22/2022] Open
Abstract
Scrub typhus is a neglected tropical disease that affects one-third of the world’s population. The disease is caused by Orientia tsutsugamushi (OT), an obligate intracellular Gram-negative bacterium. OT efficiently escapes from the endosomal pathway after entering the host cell and replicates inside cytosol. OT infection promotes cellular autophagy, the autonomous defense mechanism unlike other bacteria. This study has discussed the bacterial invasion process through the extracellular matrix and the immune response activated by the bacterium within the hosts. Furthermore, we have emphasized the importance of extracellular matrix and their cross-talk with the immune cells, such as, macrophages, neutrophils, and dendritic cells followed by their inflammatory response. We have also put an insight into the host factors associated with signaling pathways during scrub typhus disease with a special focus on the OT-induced stress response, autophagy, apoptosis, and innate immunity. Multiple cytokines and chemokines play a significant role in activating different immune-related signaling pathways. Due to the presence of high antigenic diversity among strains, the signaling pathways during the host–pathogen interplay of OT with its host is very complicated. Thus, it hinders to mitigate the severity of the pandemic occurred by the respective pathogen. Our investigation will provide a useful guide to better understand the virulence and physiology of this intracellular pathogen which will lead towards a better therapeutic diagnosis and vaccine development.
Collapse
Affiliation(s)
- Subhasmita Panda
- Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Subrat Kumar Swain
- Centre for Genomics and Biomedical Informatics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| | - Basanta Pravas Sahu
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore 453552 India
| | - Rachita Sarangi
- Department of Pediatrics, IMS and SUM Hospital, Siksha 'O' Anusandhan Deemed to be University, K8, Kalinga Nagar, Bhubaneswar, Odisha 751003 India
| |
Collapse
|
17
|
Clinical Outcomes of Doxycycline, Azithromycin, and Chloramphenicol for the Treatment of Severe Patients with Scrub Typhus. Int J Antimicrob Agents 2022; 60:106647. [DOI: 10.1016/j.ijantimicag.2022.106647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 07/12/2022] [Accepted: 07/27/2022] [Indexed: 11/23/2022]
|
18
|
Bhandari S, Bhandari S, Gautam K, Jha R, Devkota S. Meningeal Signs and Cerebellar Involvement in Scrub Typhus: A Case Report. Cureus 2022; 14:e25708. [PMID: 35812590 PMCID: PMC9270076 DOI: 10.7759/cureus.25708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2022] [Indexed: 11/05/2022] Open
|
19
|
Functional Characterization of Non-Ankyrin Repeat Domains of Orientia tsutsugamushi Ank Effectors Reveals Their Importance for Molecular Pathogenesis. Infect Immun 2022; 90:e0062821. [PMID: 35435726 DOI: 10.1128/iai.00628-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Orientia tsutsugamushi is a genetically intractable obligate intracellular bacterium, causes scrub typhus, and has one of the largest known armamentariums of ankyrin repeat-containing effectors (Anks). Most have a C-terminal F-box presumed to interact with the SCF ubiquitin ligase complex primarily based on their ability to bind overexpressed Skp1. Whether all F-box-containing Anks bind endogenous SCF components and the F-box residues essential for such interactions has gone unexplored. Many O. tsutsugamushi Ank F-boxes occur as part of a PRANC (pox protein repeats of ankyrin-C-terminal) domain. Roles of the non-F-box portion of the PRANC and intervening sequence region (ISR) that links the ankyrin repeat and F-box/PRANC domains are unknown. The functional relevance of these effectors' non-ankyrin repeat domains was investigated. The F-box was necessary for Flag-tagged versions of most F-box-containing Anks to precipitate endogenous Skp1, Cul1, and/or Rbx1, while the ISR and PRANC were dispensable. Ank toxicity in yeast was predominantly F-box dependent. Interrogations of Ank1, Ank5, and Ank6 established that L1, P2, E4, I9, and D17 of the F-box consensus are key for binding native SCF components and for Ank1 and Ank6 to inhibit NF-κB. The ISR is also essential for Ank1 and Ank6 to impair NF-κB. Ectopically expressed Ank1 and Ank6 lacking the ISR or having a mutagenized F-box incapable of binding SCF components performed as dominant-negative inhibitors to block O. tsutsugamushi NF-κB modulation. This study advances knowledge of O. tsutsugamushi Ank functional domains and offers an approach for validating their roles in infection.
Collapse
|
20
|
Liu X, Zhang Y, Zhang J, Lou Z, Xia H, Lu Z. The Early Diagnosis of Scrub Typhus by Metagenomic Next-Generation Sequencing. Front Public Health 2021; 9:755228. [PMID: 34858931 PMCID: PMC8632043 DOI: 10.3389/fpubh.2021.755228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 10/06/2021] [Indexed: 11/19/2022] Open
Abstract
Introduction: Scrub typhus is a mite-borne infection widespread in Southeast Asia, with clinical symptoms such as fever, chills, skin rash, eschar at the bite site, and other signs of acute febrile illness. The Rickettsia pathogen (Orientia tsutsugamushi) is always difficult to be diagnosed at an early stage by traditional clinical diagnostic methods, especially for patients without typical eschar. This greatly increases the mortality of patients with scrub typhus. A new approach should be introduced to improve its clinical diagnosis. Methods: During May 2018 to March 2021, 13 samples from 10 patients with suspected scrub typhus were collected. Metagenomic next-generation sequencing (mNGS) and other diagnostic methods (including serology using Weil–Felix reaction and indirect immunofluorescence test (IIFT) for scrub typhus and respiratory tract profile IgM as well as culture for routine bacteria) were used to identify the pathogens in this study. Results: The results of mNGS were all positive, with mapped reads of O. tsutsugamushi ranging from 1 to 460. Eight patients (80%) were diagnosed as scrub typhus. The other two were diagnosed as suspected scrub typhus due to the limited number of reads of the pathogen (one and two, respectively). According to clinical evidences, nine of the 10 patients were finally diagnosed as scrub typhus, except for patient 9 (suspected scrub typhus by mNGS with one specific reads of the pathogen) diagnosed as acute exacerbation of chronic obstructive pulmonary disease. For the five scrub typhus patients without typical eschar, mNGS gave all positive results (4–460 specific reads). For other methods, only Weil–Felix reaction of one patient detected the pathogen. In addition, the respiratory tract profile (IgM) detected various pathogens, but all were confirmed to be false positive. Conclusions: mNGS performed better than conventional clinical methods to early diagnose scrub typhus. This approach can be routinely carried out for early and precise diagnosis in clinical infections, especially for those hard to be identified by traditional diagnostic methods.
Collapse
Affiliation(s)
- Xianghong Liu
- Department of Neurology, Ganzhou People's Hospital, Ganzhou, China
| | - Ye Zhang
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Jun Zhang
- Emergency Department, Ganzhou People's Hospital, Ganzhou, China
| | - Zheng Lou
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Han Xia
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Zhijuan Lu
- Department of Neurology, Ganzhou People's Hospital, Ganzhou, China
| |
Collapse
|
21
|
Franchini M, Mazza G, Mori E. First assessment of ectoparasite prevalence in Apennine populations of Eurasian red squirrel: does habitat fragmentation affect parasite presence? ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2021.1967458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Marcello Franchini
- Department of Agri-Food, Environmental and Animal Sciences, University of Udine, Via Sondrio 2/A, Udine 33100, Italy
| | - Giuseppe Mazza
- CREA Research Centre for Plant Protection and Certification (CREA-DC), Via Lanciola 12/a, Firenze 50125, Italy
| | - Emiliano Mori
- National Research Council, Research Institute on Terrestrial Ecosystems, Via Madonna del Piano 10, Sesto Fiorentino (Florence) 50019, Italy
| |
Collapse
|
22
|
Halved Incidence of Scrub Typhus after Travel Restrictions to Confine a Surge of COVID-19 in Taiwan. Pathogens 2021; 10:pathogens10111386. [PMID: 34832542 PMCID: PMC8623167 DOI: 10.3390/pathogens10111386] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/20/2021] [Accepted: 10/26/2021] [Indexed: 12/03/2022] Open
Abstract
Scrub typhus is a rickettsial disease that is usually transmitted by mite exposure. Infected patients may present with a fever, fatigue, headache, and muscle pain. A blackish skin lesion, called eschar, is pathognomic. The mortality rate in untreated cases is high. The first case of scrub typhus in Taiwan was reported in 1908 during the Japanese colonization. In this article, using the National Infectious Disease Statistics System (NIDSS) from the Taiwan CDC, we analyzed the dynamic incidence of scrub typhus from 2016 to 2021, both seasonally and geographically. In addition, we asked whether the recent travel restrictions and social distancing policy in Taiwan (19 May to 27 July 2021), implemented due to the COVID-19 outbreak, would change the incidence of scrub typhus. The results showed that scrub typhus was most common in summer, with an incidence almost twofold greater than that in winter or spring. Most cases were identified in rural regions. Interestingly, there was a significant 52% reduction in the summer incidence in 2021, compared to the average summer incidence of the past 5 years. This reduction coincided with the countrywide lockdown measures and travel restrictions. The restricted measures for outdoor activities may have contributed to the reduced incidence of scrub typhus.
Collapse
|
23
|
Orientia tsutsugamushi selectively stimulates the C-type lectin receptor Mincle and type 1-skewed proinflammatory immune responses. PLoS Pathog 2021; 17:e1009782. [PMID: 34320039 PMCID: PMC8351992 DOI: 10.1371/journal.ppat.1009782] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 08/09/2021] [Accepted: 07/03/2021] [Indexed: 12/20/2022] Open
Abstract
Orientia tsutsugamushi is an obligately intracellular bacterium and the etiological agent of scrub typhus. The lung is a major target organ of infection, displaying type 1-skewed proinflammatory responses. Lung injury and acute respiratory distress syndrome are common complications of severe scrub typhus; yet, their underlying mechanisms remain unclear. In this study, we investigated whether the C-type lectin receptor (CLR) Mincle contributes to immune recognition and dysregulation. Following lethal infection in mice, we performed pulmonary differential expression analysis with NanoString. Of 671 genes examined, we found 312 significantly expressed genes at the terminal phase of disease. Mincle (Clec4e) was among the top 5 greatest up-regulated genes, accompanied with its signaling partners, type 1-skewing chemokines (Cxcr3, Ccr5, and their ligands), as well as Il27. To validate the role of Mincle in scrub typhus, we exposed murine bone marrow-derived macrophages (MΦ) to live or inactivated O. tsutsugamushi and analyzed a panel of CLRs and proinflammatory markers via qRT-PCR. We found that while heat-killed bacteria stimulated transitory Mincle expression, live bacteria generated a robust response in MΦ, which was validated by indirect immunofluorescence and western blot. Notably, infection had limited impact on other tested CLRs or TLRs. Sustained proinflammatory gene expression in MΦ (Cxcl9, Ccl2, Ccl5, Nos2, Il27) was induced by live, but not inactivated, bacteria; infected Mincle-/- MΦ significantly reduced proinflammatory responses compared with WT cells. Together, this study provides the first evidence for a selective expression of Mincle in sensing O. tsutsugamushi and suggests a potential role of Mincle- and IL-27-related pathways in host responses to severe infection. Additionally, it provides novel insight into innate immune recognition of this poorly studied bacterium.
Collapse
|
24
|
Musa TH, Ahmad T, Wana MN, Li W, Musa HH, Sharun K, Tiwari R, Dhama K, Chaicumpa W, Campbell MC, Wei P. The epidemiology, diagnosis and management of scrub typhus disease in China. Hum Vaccin Immunother 2021; 17:3795-3805. [PMID: 34124995 DOI: 10.1080/21645515.2021.1934355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Thirty-nine years ago, scrub typhus (ST), a disease, was not among the China's notifiable diseases. However, ST has reemerged to become a growing public health issue in the southwest part of China. The major factors contributing to an increased incidence and prevalence of this disease include rapid globalization, urbanization, expansion of humans into previously uninhabited areas, and climate change. The clinical manifestation of ST also consists of high fever, headache, weakness, myalgia, rash, and an eschar. In severe cases, complications (e.g. multi-organ failure, jaundice, acute renal failure, pneumonitis, myocarditis, and even death) can occur. The diagnosis of ST is mainly based on serological identification by indirect immunofluorescence assay and other molecular methods. Furthermore, several groups of antibiotics (e.g. tetracycline, chloramphenicol, macrolides, and rifampicin) are currently effective in treating this disease. This fact suggests the need for robust early diagnostic techniques, increased surveillance, and prompt treatment, and develop future vaccine.
Collapse
Affiliation(s)
- Taha Hussein Musa
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China.,Biomedical Research Institute (BRI), Darfur College, Nyala, Sudan
| | - Tauseef Ahmad
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
| | - Mohammed Nasiru Wana
- Department of Biological Sciences, Faculty of Science, Abubakar Tafawa Balewa University, Bauchi, Nigeria
| | - Wei Li
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
| | - Hassan Hussein Musa
- Faculty of Medical Laboratory Sciences, University of Khartoum, Khartoum, Sudan
| | - Khan Sharun
- Division of Surgery, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Ruchi Tiwari
- Department of Veterinary Microbiology and Immunology, College of Veterinary Sciences, UP Deen Dayal Upadhayaya Pashu Chikitsa Vigyan Vishwavidyalay Evum Go-Anusandhan Sansthan (DUVASU), Mathura, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Bareilly, India
| | - Wanpen Chaicumpa
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Pingmin Wei
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
| |
Collapse
|
25
|
Fisher JR, Chroust ZD, Onyoni F, Soong L. Pattern Recognition Receptors in Innate Immunity to Obligate Intracellular Bacteria. ZOONOSES (BURLINGTON, MASS.) 2021; 1:10. [PMID: 35282331 PMCID: PMC8909792 DOI: 10.15212/zoonoses-2021-0011] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Host pattern recognition receptors (PRRs) are crucial for sensing pathogenic microorganisms, launching innate responses, and shaping pathogen-specific adaptive immunity during infection. Rickettsia spp., Orientia tsutsugamushi, Anaplasma spp., Ehrlichia spp., and Coxiella burnetii are obligate intracellular bacteria, which can only replicate within host cells and must evade immune detection to successfully propagate. These five bacterial species are zoonotic pathogens of clinical or agricultural importance, yet, uncovering how immune recognition occurs has remained challenging. Recent evidence from in-vitro studies and animal models has offered new insights into the types and kinetics of PRR activation during infection with Rickettsia spp., A. phagocytophilum, E. chaffeensis, and C. burnetii, respectively. However, much less is known in these regards for O. tsutsugamushi infection, until the recent discovery for the role of the C-type lectin receptor Mincle during lethal infection in mice and in primary macrophage cultures. This review gives a brief summary for clinical and epidemiologic features of these five bacterial infections, focuses on fundamental biologic facets of infection, and recent advances in host recognition. In addition, we discuss knowledge gaps for innate recognition of these bacteria in the context of disease pathogenesis.
Collapse
Affiliation(s)
- James R. Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- School of Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Zachary D. Chroust
- School of Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Florence Onyoni
- Graduate School of Biomedical Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, USA
- Corresponding author: Lynn Soong, Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd. MRB 3.142, Galveston, Texas 77555-1070,
| |
Collapse
|
26
|
Berk JM, Lim C, Ronau JA, Chaudhuri A, Chen H, Beckmann JF, Loria JP, Xiong Y, Hochstrasser M. A deubiquitylase with an unusually high-affinity ubiquitin-binding domain from the scrub typhus pathogen Orientia tsutsugamushi. Nat Commun 2020; 11:2343. [PMID: 32393759 PMCID: PMC7214410 DOI: 10.1038/s41467-020-15985-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/02/2020] [Indexed: 01/07/2023] Open
Abstract
Ubiquitin mediated signaling contributes critically to host cell defenses during pathogen infection. Many pathogens manipulate the ubiquitin system to evade these defenses. Here we characterize a likely effector protein bearing a deubiquitylase (DUB) domain from the obligate intracellular bacterium Orientia tsutsugamushi, the causative agent of scrub typhus. The Ulp1-like DUB prefers ubiquitin substrates over ubiquitin-like proteins and efficiently cleaves polyubiquitin chains of three or more ubiquitins. The co-crystal structure of the DUB (OtDUB) domain with ubiquitin revealed three bound ubiquitins: one engages the S1 site, the second binds an S2 site contributing to chain specificity and the third binds a unique ubiquitin-binding domain (UBD). The UBD modulates OtDUB activity, undergoes a pronounced structural transition upon binding ubiquitin, and binds monoubiquitin with an unprecedented ~5 nM dissociation constant. The characterization and high-resolution structure determination of this enzyme should aid in its development as a drug target to counter Orientia infections.
Collapse
Affiliation(s)
- Jason M Berk
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Christopher Lim
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Judith A Ronau
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Discovery, Research and Development, AbbVie, Inc., North Chicago, IL, 60064, USA
| | - Apala Chaudhuri
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Hongli Chen
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - John F Beckmann
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36830, USA
| | - J Patrick Loria
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA
| | - Yong Xiong
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
| | - Mark Hochstrasser
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
| |
Collapse
|
27
|
Wangrangsimakul T, Greer RC, Chanta C, Nedsuwan S, Blacksell SD, Day NPJ, Paris DH. Clinical Characteristics and Outcome of Children Hospitalized With Scrub Typhus in an Area of Endemicity. J Pediatric Infect Dis Soc 2020; 9:202-209. [PMID: 30864670 PMCID: PMC7192406 DOI: 10.1093/jpids/piz014] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/31/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Scrub typhus, caused by Orientia tsutsugamushi, is a major cause of acute febrile illness in children in the rural tropics. METHODS We recruited 60 febrile pediatric patients with a positive scrub typhus rapid diagnostic test result and 40 healthy controls from Chiang Rai Province in northern Thailand. Diagnosis was confirmed by the detection of (1) O. tsutsugamushi-specific DNA in blood or eschar samples with a polymerase chain reaction assay, (2) a fourfold rise in immunoglobulin M (IgM) titer to ≥1:3200 in paired plasma samples with an indirect immunofluorescence assay (IFA), or (3) a single IgM titer of ≥1:3200 in an acute plasma sample with an IFA. Demographic, clinical, and laboratory data were collected, and patients were followed up for 1 year. RESULTS Diagnosis was confirmed in 35 (58%) of 60 patients, and all controls tested negative for scrub typhus. Patients with confirmed scrub typhus had clinical symptoms, including fever (35 of 35 [100%]), eschar (21 of 35 [60%]), cough (21 of 35 [60%]), tachypnea (16 of 35 [46%]), lymphadenopathy (15 of 35 [43%]), and headache (14 of 35 [40%]). Only 4 (11%) of 35 patients received appropriate antibiotic treatment for scrub typhus before admission. The median fever-clearance time was 36 hours (interquartile range, 24-53 hours). Complications observed include hepatitis (9 of 35 [26%]), severe thrombocytopenia (7 of 35 [20%]), pneumonitis (5 of 35 [14%]), circulatory shock (4 of 35 [11%]), and acute respiratory distress syndrome (3 of 35 [9%]). Treatment failure, defined by failure to defervesce within 72 hours of antibiotic treatment initiation, was noted in 8 (23%) of 35 patients, and 1 (3%) of the 35 patients died. No evidence of relapse or reinfection was found. CONCLUSION Pediatric scrub typhus in northern Thailand is often severe and potentially fatal with delays in treatment a likely contributing factor. Additional studies to investigate the bacterial, pharmacologic, and immunologic factors related to treatment outcome along with measures to improve public awareness should be prioritized.
Collapse
Affiliation(s)
- Tri Wangrangsimakul
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Rachel C Greer
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Chulapong Chanta
- Department of Pediatrics, Chiang Rai Prachanukroh Hospital, Thailand
| | - Supalert Nedsuwan
- Department of Family Medicine, Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand
| | - Stuart D Blacksell
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, United Kingdom
| | - Daniel H Paris
- Department of Medicine, Swiss Tropical and Public Health Institute and Faculty of Medicine, University of Basel, Switzerland
| |
Collapse
|
28
|
Atwal S, Giengkam S, Jaiyen Y, Feaga HA, Dworkin J, Salje J. Clickable methionine as a universal probe for labelling intracellular bacteria. J Microbiol Methods 2019; 169:105812. [PMID: 31862457 PMCID: PMC6996152 DOI: 10.1016/j.mimet.2019.105812] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/12/2019] [Accepted: 12/12/2019] [Indexed: 12/13/2022]
Abstract
Despite their clinical and biological importance, the cell biology of obligate intracellular bacteria is less well understood than that of many free-living model organisms. One reason for this is that they are mostly genetically intractable. As a consequence, it is not possible to engineer strains expressing fluorescent proteins and therefore fluorescence light microscopy - a key tool in host-pathogen cell biology studies - is difficult. Strain diversity also limits the universality of antibody-based immunofluorescence approaches. Here, we have developed a universal labelling protocol for intracellular bacteria based on a clickable methionine analog. Whilst we have applied this to obligate intracellular bacteria, we expect it to be useful for labelling free living bacteria as well as other intracellular pathogens.
Collapse
Affiliation(s)
- Sharanjeet Atwal
- Public Health Research Institute, Rutgers University of New Jersey, USA
| | | | - Yanin Jaiyen
- Mahidol Oxford Tropical Research Unit, Bangkok, Thailand
| | - Heather A Feaga
- Department of Microbiology & Immunology, College of Physicians and Surgeons, Columbia University, USA
| | - Jonathan Dworkin
- Department of Microbiology & Immunology, College of Physicians and Surgeons, Columbia University, USA
| | - Jeanne Salje
- Public Health Research Institute, Rutgers University of New Jersey, USA; Mahidol Oxford Tropical Research Unit, Bangkok, Thailand; University of Oxford, UK.
| |
Collapse
|
29
|
Trent B, Fisher J, Soong L. Scrub Typhus Pathogenesis: Innate Immune Response and Lung Injury During Orientia tsutsugamushi Infection. Front Microbiol 2019; 10:2065. [PMID: 31555249 PMCID: PMC6742975 DOI: 10.3389/fmicb.2019.02065] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/22/2019] [Indexed: 01/28/2023] Open
Abstract
Scrub typhus is an understudied, potentially lethal disease caused by infection with Orientia tsutsugamushi. Despite causing an estimated 1 million cases per year and an increasing global presence, mechanisms of scrub typhus pathogenesis remain unclear. One of the most life-threatening conditions that can arise in scrub typhus patients is acute respiratory distress syndrome (ARDS). The development of ARDS is a complex process; some of its pathological hallmarks, including prolonged recruitment of inflammatory immune cells to the lung and vasculature damage, have been observed in humans and/or animal models of O. tsutsugamushi infection. Although different cell types and mechanisms may contribute to ARDS development during O. tsutsugamushi infection, this review highlights our current evidence of pulmonary endothelial activation and damage, the potential roles of neutrophils and macrophages in the lung, and the knowledge gaps in this field. Continued investigation of the lung microenvironment and cellular interactions will help elucidate disease pathogenesis and possible treatment during scrub typhus.
Collapse
Affiliation(s)
- Brandon Trent
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - James Fisher
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Lynn Soong
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States.,Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| |
Collapse
|
30
|
Tantibhedhyangkul W, Wongsawat E, Matamnan S, Inthasin N, Sueasuay J, Suputtamongkol Y. Anti-Mycoplasma Activity of Daptomycin and Its Use for Mycoplasma Elimination in Cell Cultures of Rickettsiae. Antibiotics (Basel) 2019; 8:E123. [PMID: 31438510 PMCID: PMC6784056 DOI: 10.3390/antibiotics8030123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/15/2019] [Accepted: 08/17/2019] [Indexed: 12/24/2022] Open
Abstract
Mycoplasma contamination detrimentally affects cellular functions and the growth of intracellular pathogens in cell cultures. Although several mycoplasmacidal agents are commercially available for sterile cell cultures, they are not applicable to rickettsia-infected cells. In our attempt to find an anti-mycoplasma drug for contaminated rickettsial cultures, we determined the susceptibilities of three common Mycoplasma species to daptomycin. Mycoplasma orale and M. arginini showed low-level resistance to daptomycin (minimum inhibitory concentration, MIC = 2 mg/L), whereas M. hyorhinis was high-level resistant (MIC = 32 mg/L). However, some Mycoplasma isolates developed higher resistance to daptomycin after failed treatments with inadequate doses or durations. An aminoglycoside (gentamicin) was still active against M. hyorhinis and could be used in Orientia cultures. For complete eradication of mycoplasmas in Rickettsia cultures, we recommend a 3-week treatment with daptomycin at 256 mg/L. In contaminated Orientia cultures, daptomycin at 32 mg/L was effective in eradicating M. orale, whereas either gentamicin or amikacin (100 mg/L) was effective in eradicating M. hyorhinis. Unlike each drug alone, the combinations of daptomycin plus clindamycin and/or quinupristin/dalfopristin proved effective in eradicating M. hyorhinis. In summary, our study demonstrated the in vitro anti-mycoplasma activity of daptomycin and its application as a new mycoplasma decontamination method for Rickettsia and Orientia cultures.
Collapse
Affiliation(s)
- Wiwit Tantibhedhyangkul
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
| | - Ekkarat Wongsawat
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Sutthicha Matamnan
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Naharuthai Inthasin
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jintapa Sueasuay
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Yupin Suputtamongkol
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| |
Collapse
|
31
|
Lalchhandama K. Orientia tsutsugamushi, the agent of scrub typhus. WIKIJOURNAL OF MEDICINE 2019. [DOI: 10.15347/wjm/2019.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
32
|
Ponnusamy L, Willcox AC, Roe RM, Davidson SA, Linsuwanon P, Schuster AL, Richards AL, Meshnick SR, Apperson CS. Bacterial microbiome of the chigger mite Leptotrombidium imphalum varies by life stage and infection with the scrub typhus pathogen Orientia tsutsugamushi. PLoS One 2018; 13:e0208327. [PMID: 30521561 PMCID: PMC6283546 DOI: 10.1371/journal.pone.0208327] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 11/15/2018] [Indexed: 02/01/2023] Open
Abstract
Scrub typhus is a mites-borne rickettsiosis caused by the obligate intracellular Gram-negative bacterium Orientia tsutsugamushi. The disease is potentially life threatening and is prevalent in tropical Asia, islands of the western Pacific Ocean and northern Australia where an estimated one million cases occur annually. Orientia tsutsugamushi is transmitted by the bite of larval mites in the genus Leptotrombidium. In the present study, the composition of the microbiome in larvae, deutonymphs and adult males and females from laboratory colonies of L. imphalum that were infected as well as uninfected with O. tsutsugamushi were investigated by high-throughput sequencing of the bacterial 16S rRNA gene. Notably, the bacterial microbiomes of infected adult females were dominated by sequences of O. tsutsugamushi and an unidentified species of Amoebophilaceae, which together comprised 98.2% of bacterial sequences. To improve the taxonomic resolution of the Amoebophilaceae OTU a nearly full length sequence of the 16S rRNA gene was amplified, cloned, and Sanger sequenced. Infected female mites had 89 to 92% nucleotide identity with the Amoebophilaceae family, indicating that the bacterium was likely to be a species of a novel genus. The species composition of bacterial communities varied between mite life stages regardless of their infection status. Uninfected adults exhibited greater species diversity than adults infected with O. tsutsugamushi. In the infected colony, the rate of filial infection with Orientia was less than 100%. Larval and male mites that were PCR-negative for Orientia contained low numbers of sequences of Amoebophilaceae (0.01 and 0.06%, respectively) in their taxonomic profiles, suggesting that a mutualistic relationship exists between the novel species of Amoebophilaceae and O. tsutsugamushi. Our study findings provide the basis for further research to determine the influence of the novel Amoebophilaceae species on the bacterial microbiome and on vector susceptibility to and transovarial transmission of O. tsutsugamushi.
Collapse
Affiliation(s)
- Loganathan Ponnusamy
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail: (LP); (CSA)
| | - Alexandra C. Willcox
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - R. Michael Roe
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Silas A. Davidson
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Piyada Linsuwanon
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Anthony L. Schuster
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Allen L. Richards
- Naval Medical Research Center, Viral and Rickettsial Diseases Department, Silver Spring, Maryland, United States of America
| | - Steven R. Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Charles S. Apperson
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail: (LP); (CSA)
| |
Collapse
|
33
|
Chung M, Munro JB, Tettelin H, Dunning Hotopp JC. Using Core Genome Alignments To Assign Bacterial Species. mSystems 2018; 3:e00236-18. [PMID: 30534598 PMCID: PMC6280431 DOI: 10.1128/msystems.00236-18] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 10/11/2018] [Indexed: 12/14/2022] Open
Abstract
With the exponential increase in the number of bacterial taxa with genome sequence data, a new standardized method to assign species designations is needed that is consistent with classically obtained taxonomic analyses. This is particularly acute for unculturable, obligate intracellular bacteria with which classically defined methods, like DNA-DNA hybridization, cannot be used, such as those in the Rickettsiales. In this study, we generated nucleotide-based core genome alignments for a wide range of genera with classically defined species, as well as those within the Rickettsiales. We created a workflow that uses the length, sequence identity, and phylogenetic relationships inferred from core genome alignments to assign genus and species designations that recapitulate classically obtained results. Using this method, most classically defined bacterial genera have a core genome alignment that is ≥10% of the average input genome length. Both Anaplasma and Neorickettsia fail to meet this criterion, indicating that the taxonomy of these genera should be reexamined. Consistently, genomes from organisms with the same species epithet have ≥96.8% identity of their core genome alignments. Additionally, these core genome alignments can be used to generate phylogenomic trees to identify monophyletic clades that define species and neighbor-network trees to assess recombination across different taxa. By these criteria, Wolbachia organisms are delineated into species different from the currently used supergroup designations, while Rickettsia organisms are delineated into 9 distinct species, compared to the current 27 species. By using core genome alignments to assign taxonomic designations, we aim to provide a high-resolution, robust method to guide bacterial nomenclature that is aligned with classically obtained results. IMPORTANCE With the increasing availability of genome sequences, we sought to develop and apply a robust, portable, and high-resolution method for the assignment of genera and species designations that can recapitulate classically defined taxonomic designations. Using cutoffs derived from the lengths and sequence identities of core genome alignments along with phylogenetic analyses, we sought to evaluate or reevaluate genus- and species-level designations for diverse taxa, with an emphasis on the order Rickettsiales, where species designations have been applied inconsistently. Our results indicate that the Rickettsia genus has an overabundance of species designations, that the current Anaplasma and Neorickettsia genus designations are both too broad and need to be divided, and that there are clear demarcations of Wolbachia species that do not align precisely with the existing supergroup designations.
Collapse
Affiliation(s)
- Matthew Chung
- Institute for Genome Sciences, University of Maryland Baltimore, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - James B. Munro
- Institute for Genome Sciences, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - Hervé Tettelin
- Institute for Genome Sciences, University of Maryland Baltimore, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - Julie C. Dunning Hotopp
- Institute for Genome Sciences, University of Maryland Baltimore, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland Baltimore, Baltimore, Maryland, USA
- Greenebaum Comprehensive Cancer Center, University of Maryland Baltimore, Baltimore, Maryland, USA
| |
Collapse
|
34
|
Flieger A, Frischknecht F, Häcker G, Hornef MW, Pradel G. Pathways of host cell exit by intracellular pathogens. MICROBIAL CELL 2018; 5:525-544. [PMID: 30533418 PMCID: PMC6282021 DOI: 10.15698/mic2018.12.659] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Host cell exit is a critical step in the life-cycle of intracellular pathogens, intimately linked to barrier penetration, tissue dissemination, inflammation, and pathogen transmission. Like cell invasion and intracellular survival, host cell exit represents a well-regulated program that has evolved during host-pathogen co-evolution and that relies on the dynamic and intricate interplay between multiple host and microbial factors. Three distinct pathways of host cell exit have been identified that are employed by three different taxa of intracellular pathogens, bacteria, fungi and protozoa, namely (i) the initiation of programmed cell death, (ii) the active breaching of host cellderived membranes, and (iii) the induced membrane-dependent exit without host cell lysis. Strikingly, an increasing number of studies show that the majority of intracellular pathogens utilize more than one of these strategies, dependent on life-cycle stage, environmental factors and/or host cell type. This review summarizes the diverse exit strategies of intracellular-living bacterial, fungal and protozoan pathogens and discusses the convergently evolved commonalities as well as system-specific variations thereof. Key microbial molecules involved in host cell exit are highlighted and discussed as potential targets for future interventional approaches.
Collapse
Affiliation(s)
- Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | | | - Georg Häcker
- Institute of Medical Microbiology and Hygiene, Medical Center - University of Freiburg, Germany
| | - Mathias W Hornef
- Institute of Medical Microbiology, RWTH Aachen University Hospital, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, Institute of Biology II, RWTH Aachen University, Germany
| |
Collapse
|