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1.
Drug Resist Updat ; 76: 101121, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39018660

RESUMO

In a clinical isolate of Burkholderia pseudomallei from Hainan, the association between the emergence of ceftazidime resistance and a novel PenA P174L allele was identified for the first time, providing an understanding of one mechanism by which ceftazidime resistance arises in B. pseudomallei.


Assuntos
Antibacterianos , Burkholderia pseudomallei , Ceftazidima , Farmacorresistência Bacteriana , Melioidose , Testes de Sensibilidade Microbiana , Mutação Puntual , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/efeitos dos fármacos , Ceftazidima/farmacologia , Humanos , China , Antibacterianos/farmacologia , Melioidose/microbiologia , Melioidose/tratamento farmacológico , Farmacorresistência Bacteriana/genética , Proteínas de Bactérias/genética , Alelos
2.
PLoS Negl Trop Dis ; 18(7): e0012317, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39018296

RESUMO

BACKGROUND: Melioidosis, a life-threatening infection caused by the gram negative bacterium Burkholderia pseudomallei, can involve almost any organ. Bone and joint infections (BJI) are a recognised, but incompletely defined, manifestation of melioidosis that are associated with significant morbidity and mortality in resource-limited settings. METHODOLOGY/PRINCIPAL FINDINGS: We identified all individuals with BJI due to B. pseudomallei managed at Cairns Hospital in tropical Australia between January 1998 and June 2023. The patients' demographics, their clinical findings and their treatment were correlated with their subsequent course. Of 477 culture-confirmed cases of melioidosis managed at the hospital during the study period, 39 (8%) had confirmed BJI; predisposing risk factors for melioidosis were present in 37/39 (95%). However, in multivariable analysis only diabetes mellitus was independently associated with the presence of BJI (odds ratio (95% confidence interval): 4.04 (1.81-9.00), p = 0.001). BJI was frequently only one component of multi-organ involvement: 29/39 (74%) had infection involving other organs and bacteraemia was present in 31/39 (79%). Of the 39 individuals with BJI, 14 (36%) had osteomyelitis, 8 (20%) had septic arthritis and 17 (44%) had both osteomyelitis and septic arthritis; in 32/39 (83%) the lower limb was involved. Surgery was performed in 30/39 (77%). Readmission after the initial hospitalisation was necessary in 11/39 (28%), 5/39 (13%) had disease recrudescence and 3/39 (8%) had relapse; 4/39 (10%) developed pathological fractures. ICU admission was necessary in 11/39 (28%) but all 11 of these patients survived. Only 1/39 (3%) died, 138 days after admission, due to his significant underlying comorbidity. CONCLUSIONS: The case-fatality rate from melioidosis BJI in Australia's well-resourced health system is very low. However, recrudescence, relapse and orthopaedic complications are relatively common and emphasise the importance of collaborative multidisciplinary care that includes early surgical review, aggressive source control, prolonged antibiotic therapy, and thorough, extended follow-up.


Assuntos
Burkholderia pseudomallei , Melioidose , Humanos , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Masculino , Feminino , Pessoa de Meia-Idade , Burkholderia pseudomallei/isolamento & purificação , Adulto , Idoso , Antibacterianos/uso terapêutico , Fatores de Risco , Osteomielite/microbiologia , Osteomielite/diagnóstico , Osteomielite/terapia , Adulto Jovem , Austrália/epidemiologia , Artrite Infecciosa/microbiologia , Artrite Infecciosa/terapia , Artrite Infecciosa/diagnóstico , Artrite Infecciosa/mortalidade , Estudos Retrospectivos , Adolescente , Resultado do Tratamento
3.
Acta Trop ; 254: 107209, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38599443

RESUMO

Melioidosis is a life-threatening, emerging infectious disease caused by the environmental bacterium Burkholderia pseudomallei. Melioidosis is hyperendemic in tropical Australia and southeast Asia, however the disease is increasingly encountered beyond these regions. Early diagnosis is essential as the infection has a case-fatality rate of up to 50 %. Melioidosis most commonly involves the lungs, although almost any organ can be affected. Most patients present acutely but an insidious presentation over weeks to months is also well described. We present a case series of 7 patients from tropical Australia whom local clinicians initially believed to have cancer ‒ most commonly lung cancer ‒ only for further investigation to establish a diagnosis of melioidosis. All 7 patients had comorbidities that predisposed them to developing melioidosis and all survived, but their delayed diagnosis resulted in 3 receiving anti-cancer therapies that resulted in significant morbidity. The study emphasises the importance of thorough diagnostic evaluation and repeated collection of microbiological samples. It is hoped that our experience will encourage other clinicians ‒ in the appropriate clinical context ‒ to consider melioidosis as a potential explanation for a patient's presentation, expediting its diagnosis and the initiation of potentially life-saving therapy.


Assuntos
Burkholderia pseudomallei , Melioidose , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Melioidose/microbiologia , Humanos , Masculino , Austrália , Pessoa de Meia-Idade , Burkholderia pseudomallei/isolamento & purificação , Feminino , Idoso , Adulto , Diagnóstico Diferencial , Neoplasias/diagnóstico
4.
Am J Trop Med Hyg ; 109(6): 1233-1237, 2023 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-37955316

RESUMO

Prostatic abscess is a common manifestation of melioidosis in men, but the characteristics of female genitourinary melioidosis are incompletely defined. There were 453 cases of melioidosis in Far North Queensland, tropical Australia, between January 1998 and April 2023; genitourinary involvement was less common in women than in men (13/140 [9%] versus 76/313 [24%], odds ratio [95% confidence interval]: 0.32 [0.17-0.60], P = 0.0004). In 11 of these 13 (85%) women, other organs were also affected. The two women with disease involving only the genitourinary tract had underlying anatomical abnormalities: one had an ovarian malignancy, the only case to involve the female reproductive system in the cohort, while the other had a urethral diverticulum. In 3 of 13 (23%) women, genitourinary involvement was identified only with computed tomography, emphasizing the importance of early imaging of patients with melioidosis to identify unexpected foci of disease and to inform the optimal duration of antibiotic therapy.


Assuntos
Burkholderia pseudomallei , Melioidose , Doenças Prostáticas , Masculino , Humanos , Feminino , Melioidose/diagnóstico por imagem , Melioidose/tratamento farmacológico , Austrália/epidemiologia , Queensland , Tomografia Computadorizada por Raios X
5.
J Infect Dev Ctries ; 17(6): 886-890, 2023 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-37406064

RESUMO

A 12-year-old boy was admitted after 11 days of fever and 2 days of nasal obstruction as well as swelling of a right cervical lymph node. Nasal endoscopy and computed tomography of the neck showed a nasopharyngeal mass occupying the entire nasopharynx, extending into the nasal cavity, and obliterating the fossa of Rosenmuller. Abdominal ultrasonography revealed a small solitary splenic abscess. Although a nasopharyngeal tumor or malignancy was initially considered, biopsy of the mass showed only suppurative granulomatous inflammation, and bacterial culture from the enlarged cervical lymph node yielded Burkholderia pseudomallei. The symptoms, nasopharyngeal mass, and cervical lymph node enlargement resolved with melioidosis-directed antibiotic therapy. Although rarely reported, the nasopharynx may be an important primary site of infection in melioidosis patients, especially in pediatric patients.


Assuntos
Burkholderia pseudomallei , Linfadenopatia , Melioidose , Neoplasias Nasofaríngeas , Esplenopatias , Masculino , Humanos , Criança , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico , Antibacterianos/uso terapêutico , Nasofaringe
6.
J Travel Med ; 30(3)2023 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-36971472

RESUMO

BACKGROUND: Melioidosis, caused by Burkholderia pseudomallei, may be considered a neglected tropical disease that remains underdiagnosed in many geographical areas. Travellers can act as the sentinels of disease activity, and data from imported cases may help complete the global map of melioidosis. METHODS: A literature search for imported melioidosis for the period 2016-22 was performed in PubMed and Google Scholar. RESULTS: In total, 137 reports of melioidosis associated with travel were identified. The majority were males (71%) and associated with exposure in Asia (77%) (mainly Thailand, 41%, and India, 9%). A minority acquired the infection in the Americas-Caribbean area (6%), Africa (5%) and Oceania (2%). The most frequent comorbidity was diabetes mellitus (25%) followed by underlying pulmonary, liver or renal disease (8, 5 and 3%, respectively). Alcohol/tobacco use were noted for seven and six patients, respectively (5%). Five patients (4%) had associated non-human immunodeficiency virus (HIV)-related immunosuppression, and three patients (2%) had HIV infection. One patient (0.8%) had concomitant coronavirus disease 19. A proportion (27%) had no underlying diseases. The most frequent clinical presentations included pneumonia (35%), sepsis (30%) and skin/soft tissue infections (14%). Most developed symptoms <1 week after return (55%), and 29% developed symptoms >12 weeks after. Ceftazidime and meropenem were the main treatments used during the intensive intravenous phase (52 and 41% of patients, respectively) and the majority (82%) received co-trimoxazole alone/combination, for the eradication phase. Most patients had a favourable outcome/survived (87%). The search also retrieved cases in imported animals or cases secondary to imported commercial products. CONCLUSIONS: As post-pandemic travel soars, health professionals should be aware of the possibility of imported melioidosis with its diverse presentations. Currently, no licensed vaccine is available, so prevention in travellers should focus on protective measures (avoiding contact with soil/stagnant water in endemic areas). Biological samples from suspected cases require processing in biosafety level 3 facilities.


Assuntos
Burkholderia pseudomallei , COVID-19 , Infecções por HIV , Melioidose , Masculino , Animais , Humanos , Feminino , Melioidose/diagnóstico , Melioidose/epidemiologia , Melioidose/tratamento farmacológico , Viagem , Infecções por HIV/complicações , Fatores de Risco , COVID-19/epidemiologia , COVID-19/complicações , Tailândia , Antibacterianos/uso terapêutico
7.
PLoS One ; 18(2): e0280944, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36758060

RESUMO

Melioidosis is an infectious disease with high mortality rates in human, caused by the bacterium Burkholderia pseudomallei. As an intracellular pathogen, B. pseudomallei can escape from the phagosome and induce multinucleated giant cells (MNGCs) formation resulting in antibiotic resistance and immune evasion. A novel strategy to modulate host response against B. pseudomallei pathogenesis is required. In this study, an active metabolite of vitamin D3 (1α,25-dihydroxyvitamin D3 or 1α,25(OH)2D3) was selected to interrupt pathogenesis of B. pseudomallei in a human lung epithelium cell line, A549. The results demonstrated that pretreatment with 10-6 M 1α,25(OH)2D3 could reduce B. pseudomallei internalization to A549 cells at 4 h post infection (P < 0.05). Interestingly, the presence of 1α,25(OH)2D3 gradually reduced MNGC formation at 8, 10 and 12 h compared to that of the untreated cells (P < 0.05). Furthermore, pretreatment with 10-6 M 1α,25(OH)2D3 considerably increased hCAP-18/LL-37 mRNA expression (P < 0.001). Additionally, pro-inflammatory cytokines, including MIF, PAI-1, IL-18, CXCL1, CXCL12 and IL-8, were statistically decreased (P < 0.05) in 10-6 M 1α,25(OH)2D3-pretreated A549 cells by 12 h post-infection. Taken together, this study indicates that pretreatment with 10-6 M 1α,25(OH)2D3 has the potential to reduce the internalization of B. pseudomallei into host cells, decrease MNGC formation and modulate host response during B. pseudomallei infection by minimizing the excessive inflammatory response. Therefore, 1α,25(OH)2D3 supplement may provide an effective supportive treatment for melioidosis patients to combat B. pseudomallei infection and reduce inflammation in these patients.


Assuntos
Melioidose , Humanos , Melioidose/tratamento farmacológico , Vitamina D , Vitaminas , Células Epiteliais/metabolismo , Pulmão/metabolismo , Células Gigantes/metabolismo , Suplementos Nutricionais
8.
Am J Trop Med Hyg ; 108(2): 293-295, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36535255

RESUMO

This report is on a 45-year-old male patient without underlying disease who presented with a Burkholderia pseudomallei-caused keratoscleritis in his right eye. Slit-lamp examination revealed multiple, indistinct corneal infiltrations with subconjunctival/scleral abscesses. Corneal tissue culture was positive for B. pseudomallei and confirmed by mass spectrometry. The patient was treated with fortified ceftazidime, fortified gentamicin eyedrops, and intravenous ceftazidime injection. Penetrating keratoplasty, including intracameral ceftazidime injections, was undertaken due to corneal lesion worsening. Scleral debridement with subconjunctival ceftazidime injections were undertaken due to the progression of the scleral abscess. After 2 months, the corneal and scleral lesions were inactive, and the systemic and topical antibiotics were tapered. This is the first case report of B. pseudomallei-caused keratoscleritis with photography. The patient was seen in an endemic geographical area with multiple corneal infiltrations and subconjunctival/scleral abscess. Systemic and topical antibiotics accompanied with surgery should be considered.


Assuntos
Burkholderia pseudomallei , Ceratite , Melioidose , Masculino , Humanos , Pessoa de Meia-Idade , Ceftazidima/uso terapêutico , Abscesso/tratamento farmacológico , Antibacterianos/uso terapêutico , Ceratite/complicações , Melioidose/complicações , Melioidose/diagnóstico , Melioidose/tratamento farmacológico
9.
BMC Infect Dis ; 22(1): 549, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35705895

RESUMO

BACKGROUND: Melioidosis caused by Burkholderia pseudomallei is an emerging infection in Sri Lanka with a high case fatality rate. The disease usually manifests as pneumonia, however multisystem involvement is common. Myositis is an extremely rare occurrence and this is the only documented case where the initial presentation of melioidosis has been myositis and later complicated to myonecrosis. CASE PRESENTATION: A 45-year-old gentleman with pre-existing diabetes presented with a tender, right thigh lump for 1 week duration without any history of trauma or infection. Investigations revealed neutrophil leukocytosis, high erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels whilst ultrasonography showed focal myositis of right quadriceps. The patient went into sepsis amidst antibacterial treatment which warranted urgent surgery. At surgery, a large intramuscular abscess with myonecrosis was observed within vastus medialis which was completely drained and pus was taken for culture which eventually isolated Burkholderia pseudomallei. Melioidosis was diagnosed and intravenous meropenem was prescribed for 3 weeks. Following complete recovery, the patient was discharged on doxycycline and trimethoprim sulfamethoxazole for 3 months. CONCLUSIONS: Melioidosis, an endemic disease in south east Asia and northern Australia, is an emerging infection in Sri Lanka. Myositis is a rare presentation of the disease that can lead to myonecrosis and abscess formation which can cause rapid disease escalation and sepsis. Early surgical intervention may be life-saving in such cases where antibiotic therapy alone may not suffice.


Assuntos
Burkholderia pseudomallei , Melioidose , Miosite , Sepse , Abscesso/microbiologia , Antibacterianos/uso terapêutico , Humanos , Masculino , Melioidose/complicações , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Pessoa de Meia-Idade , Miosite/complicações , Miosite/diagnóstico , Sepse/complicações , Sepse/etiologia , Sri Lanka
10.
Neurol India ; 70(2): 778-780, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35532659

RESUMO

Melioidosis is an emerging tropical disease. Central nervous system (CNS) melioidosis may present as a brain abscess or encephalomyelitis mimics tuberculosis. Early diagnosis and management decreases mortality as well as morbidity. This case of brain abscess and encephalomyelitis in a young man with no known comorbidities was a diagnostic challenge. The surgery helped in debulking as well as isolating the causative organism. Appropriate antibiotic therapy for melioidosis was lifesaving and prevented further complications.


Assuntos
Abscesso Encefálico , Burkholderia pseudomallei , Encefalomielite , Melioidose , Antibacterianos/uso terapêutico , Abscesso Encefálico/diagnóstico , Sistema Nervoso Central , Encefalomielite/tratamento farmacológico , Humanos , Masculino , Melioidose/complicações , Melioidose/diagnóstico , Melioidose/tratamento farmacológico
11.
Rev. chil. infectol ; 38(6): 816-819, dic. 2021. ilus
Artigo em Espanhol | LILACS | ID: biblio-1388311

RESUMO

Resumen La melioidosis es endémica en varias regiones, con predominio en el Sudeste Asiático, norte de Australia, sur de Asia, China y Taiwán. En Sudamérica, Colombia ocupa el segundo lugar de casos de melioidosis, después de Brasil. Su manifestación clínica es variable, desde una infección asintomática hasta un compromiso multiorgánico con formación de abscesos múltiples y choque séptico. El compromiso cardiaco es inusual, con una incidencia menor del 1%. Se presenta el caso de un varón de 51 años, colombiano, con antecedente de una valvula aórtica mecánica, quien presentó un absceso en la pierna derecha y en la válvula cardiaca protésica, aislándose Burkholderia pseudomallei en hemocultivos y en el cultivo de secreción de la pierna. Fue tratado con meropenem y cotrimoxazol, con una adecuada respuesta clínica, requiriendo un reemplazo valvular aórtico.


Abstract Melioidosis is an endemic disease to several regions and occurs predominantly in Southern Asia, Northern Australia, China and Taiwan. In South America, Colombia is second after Brazil in number of melioidosis cases reported. Clinical manifestation varies from asymptomatic infection to multiorgan compromise involving multiple abscesses and septic shock. Cardiac compromise is infrequent, with an incidence of <1%. We report the case of a 51-year-old patient from Colombia with a mechanical aortic valve who had an abscess in right leg and in the prosthetic valve. Burkholderia pseudomallei was isolated in blood cultures and drained pus from the leg cultures. Patient was treated with meropenem and cotrimoxazole and required aortic valve replacement, resulting in adequate improvement in clinical symptoms.


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Próteses Valvulares Cardíacas/efeitos adversos , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/tratamento farmacológico , Melioidose/complicações , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Abscesso/tratamento farmacológico , Endocardite , Antibacterianos/uso terapêutico
12.
BMJ Case Rep ; 14(6)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127500

RESUMO

A 26-year-old man, returned to the UK having travelled extensively in Asia. He was referred with a 3-month history of distal leg ulceration following an insect bite while in Thailand. Despite multiple courses of oral antibiotics, he developed two adjacent ulcers. A wound swab isolated an organism identified as Burkholderia thailandensis The histology of the skin biopsy was non-specific. A diagnosis of cutaneous melioidosis was made, based on clinical and microbiological grounds. The ulcers re-epithelialised on completion of intravenous ceftazidime followed by 3 months of high dose co-trimoxazole and wound care. Many clinical microbiology laboratories have limited diagnostics for security-related organisms, with the result that B. pseudomallei, the causative bacterium of melioidosis, may be misidentified. This case highlights the importance of maintaining high levels of clinical suspicion and close microbiological liaison in individuals returning from South-East Asia and northern Australia with such symptoms.


Assuntos
Burkholderia pseudomallei , Melioidose , Adulto , Sudeste Asiático , Austrália , Burkholderia , Humanos , Perna (Membro) , Masculino , Melioidose/complicações , Melioidose/diagnóstico , Melioidose/tratamento farmacológico , Tailândia , Úlcera
14.
Am J Trop Med Hyg ; 104(4): 1260-1264, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432905

RESUMO

Organisms penetrate the central nervous system (CNS) via three routes. The commonest is the hematogenous route, and other routes include contiguous or penetrating injury or rarely via retrograde axoplasmic route. Although the axoplasmic highway is often used by viruses, only a few bacteria are known to penetrate the CNS via this route. We present a 57-year-old man who developed a penetrating injury while working in a field. Over the next 4 months, he developed pain at the site of the poorly healing wound, which ascended up the right leg and presented as a conus-cauda syndrome. Magnetic resonance imaging (MRI) showed an enhancing intradural intramedullary enhancing lesion in the conus on the right side with cord edema from D11 to L1 level. Extensive evaluation was negative, and he continued to progress to holocord myelitis and developed bilateral corticospinal tract lesions ("tractopathy") in the brain stem and internal capsule. He died after developing a right-sided cerebritis with mass effect. Tissue biopsy from the brain at the time of decompressive craniectomy grew Burkholderia pseudomallei and confirmed a diagnosis of neuromelioidosis (NM). We reviewed the literature for NM, its variable presentations, and the concept of an "infectious tractopathy" and imaging findings which could generate suspicion of this entity.


Assuntos
Traumatismos do Pé/complicações , Pé/microbiologia , Encefalite Infecciosa/diagnóstico por imagem , Encefalite Infecciosa/microbiologia , Melioidose/complicações , Mielite/complicações , Antibacterianos/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/microbiologia , Burkholderia pseudomallei/patogenicidade , Evolução Fatal , Pé/patologia , Traumatismos do Pé/microbiologia , Humanos , Encefalite Infecciosa/tratamento farmacológico , Encefalite Infecciosa/etiologia , Imageamento por Ressonância Magnética , Masculino , Melioidose/diagnóstico por imagem , Melioidose/tratamento farmacológico , Pessoa de Meia-Idade , Medula Espinal/patologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-33318017

RESUMO

The Gram-negative bacterial genus Burkholderia includes several hard-to-treat human pathogens: two biothreat species, Burkholderia mallei (causing glanders) and B. pseudomallei (causing melioidosis), and the B. cepacia complex (BCC) and B. gladioli, which cause chronic lung infections in persons with cystic fibrosis. All Burkholderia spp. possess an Ambler class A Pen ß-lactamase, which confers resistance to ß-lactams. The ß-lactam-ß-lactamase inhibitor combination sulbactam-durlobactam (SUL-DUR) is in clinical development for the treatment of Acinetobacter infections. In this study, we evaluated SUL-DUR for in vitro and in vivo activity against Burkholderia clinical isolates. We measured MICs of SUL-DUR against BCC and B. gladioli (n = 150), B. mallei (n = 30), and B. pseudomallei (n = 28), studied the kinetics of inhibition of the PenA1 ß-lactamase from B. multivorans and the PenI ß-lactamase from B. pseudomallei by durlobactam, tested for blaPenA1 induction by SUL-DUR, and evaluated in vivo efficacy in a mouse model of melioidosis. SUL-DUR inhibited growth of 87.3% of the BCC and B. gladioli strains and 100% of the B. mallei and B. pseudomallei strains at 4/4 µg/ml. Durlobactam potently inhibited PenA1 and PenI with second-order rate constant for inactivation (k2/K) values of 3.9 × 106 M-1 s-1 and 2.6 × 103 M-1 s-1 and apparent Ki (Kiapp) of 15 nM and 241 nM, respectively, by forming highly stable covalent complexes. Neither sulbactam, durlobactam, nor SUL-DUR increased production of PenA1. SUL-DUR demonstrated activity in vivo in a murine melioidosis model. Taken together, these data suggest that SUL-DUR may be useful as a treatment for Burkholderia infections.


Assuntos
Burkholderia mallei , Burkholderia pseudomallei , Burkholderia , Mormo , Melioidose , Animais , Antibacterianos/farmacologia , Mormo/tratamento farmacológico , Cavalos , Melioidose/tratamento farmacológico , Camundongos , Sulbactam/farmacologia
16.
Sci Rep ; 10(1): 16923, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33037311

RESUMO

Burkholderia pseudomallei (Bpm) is a bacterial pathogen that causes Melioidosis, a disease with up to 40% mortality and an infection relapse of 15-23% despite antibiotic treatment. Ineffective clearance of Bpm by antibiotics is believed to be due to persistence, a hibernation-like survival mechanism modulated, in part, by toxin-antitoxin systems (TAS). Several organisms possess a repertoire of TASs but defining environmental cues eliciting their activity is hindered by laborious in vitro experiments, especially when there are many toxins with redundant function. Here, we identified which of 103 proteins in Bpm that share features found in toxins of the TAS and repurposed transcriptional data to identify which ones play a role in surviving intracellular host defenses. Putative toxins with the strongest transcriptional response were found to have low conservation between Bpm strains, while toxins that were constitutively expressed were highly conserved. Further examination of highly conserved toxins BPSS0899, BPSS1321, and BPSL1494 showed that they were functional, and their mutation led to reduce survival within macrophages and reduced in vivo persistence-associated pathology (abscesses) during treatment, but did not affect macrophages persistence. These findings highlight the utility of a data-driven approach to select putative toxins and suggests a selective role for some TAS in host survival.


Assuntos
Burkholderia pseudomallei/metabolismo , Sistemas Toxina-Antitoxina/fisiologia , Toxinas Biológicas/metabolismo , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Burkholderia pseudomallei/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Melioidose/tratamento farmacológico , Melioidose/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Sistemas Toxina-Antitoxina/efeitos dos fármacos , Células U937
17.
PLoS Negl Trop Dis ; 14(9): e0008659, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32986699

RESUMO

BACKGROUND: Melioidosis therapy is divided into an intravenous intensive phase and an oral eradication phase. The Darwin melioidosis treatment guideline has evolved over two decades, with over 1150 consecutive patients with culture-confirmed melioidosis managed under the Darwin Prospective Melioidosis Study. The current guideline, published in 2015, has been associated with low rates of recrudescence, relapse and mortality, and together with the treatment trials in Thailand, forms the basis for consensus global guidelines. We aimed to reassess the Darwin guideline and determine if any adjustments to the recommendations better reflect current practice in melioidosis therapy at Royal Darwin Hospital. METHODOLOGY/PRINCIPAL FINDINGS: This retrospective cohort study reviews the characteristics, admission duration, duration of intravenous antibiotics, recrudescence, recurrence and mortality in all patients presenting with first episode culture-confirmed melioidosis in the tropical north of Australia's Northern Territory from 1st October 2012 until 1st January 2017. 234 patients were available for analysis. 16 (6.8%) died during the intensive phase treatment and 6 (2.6%) did not have complete treatment at Royal Darwin Hospital, leaving 212 patients for analysis. Six (2.8%) patients had recrudescence during therapy and 10 (4.7%) had recurrent melioidosis (relapse or new infection) after completion of therapy. Persisting osteomyelitis requiring surgery was an important reason for recrudescence as was unrecognized osteomyelitis for relapse. For patients presenting with an antibiotic duration determining focus of pneumonia, durations of intravenous antibiotics were often prolonged beyond the current 2-week minimum treatment recommendation. Prolongation of therapy in pneumonia mostly occurred in patients presenting with multi-lobar disease or with concurrent blood culture positivity. CONCLUSIONS/SIGNIFICANCE: The 2015 Darwin melioidosis guideline is working well with low rates of recrudescence, relapse and mortality. Based on the practice of the treating clinicians, the 2020 revision of the guideline has been adjusted to include a duration of a minimum of 3 weeks of intravenous antibiotics for those with concurrent bacteraemia and pneumonia involving only a single lobe and those with bilateral and unilateral multi-lobar pneumonias who do not have bacteraemia. We also extend to a minimum of 4 weeks intravenous therapy for those with concurrent bacteraemia and bilateral or unilateral multi-lobar pneumonia.


Assuntos
Antibacterianos/uso terapêutico , Melioidose/tratamento farmacológico , Melioidose/genética , Seleção Genética , Administração Intravenosa/métodos , Adulto , Bacteriemia/tratamento farmacológico , Burkholderia pseudomallei , Feminino , Guias como Assunto , Humanos , Masculino , Melioidose/mortalidade , Pessoa de Meia-Idade , Northern Territory , Osteomielite/cirurgia , Estudos Prospectivos , Recidiva , Estudos Retrospectivos , Tailândia
18.
PLoS Negl Trop Dis ; 14(8): e0008525, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32785225

RESUMO

Burkholderia pseudomallei is the causative agent of melioidosis, endemic in Southeast Asia and Northern Australia, and increasingly recognized in southern China, especially in Hainan Province. Mycotic aneurysm caused by B. pseudomallei is a rare but potentially severe illness with a high mortality rate. The clinical features of the mycotic aneurysm secondary to melioidosis have not been illustrated in China. Over a seven-year period (2013 to 2019), 159 patients with bacteremic melioidosis were retrospectively analyzed in Hainan province, China, of whom eight patients were confirmed to have mycotic aneurysm through the combination of imaging examination, pathologic examination and aneurysm tissue culture. We summarized these eight patients' clinical characteristics, demographical features, treatments and outcomes. The susceptibilities to five commonly-used antibiotics for these eight B. pseudomallei isolates were also determined by E-test strips. Furthermore, the mycotic aneurysm cases secondary to melioidosis retrieved from the literature were also reviewed. Of the eight cases, six had abdominal mycotic aneurysms, one had a left iliac aneurysm, and the other one had an infectious mesenteric aneurysm. They were aged from 48 to 69 years old, and had the underlying risk factors of diabetes mellitus (2 patients), long-term smoking (4 patients), hypertension (6 patients), and soil and water contact history (6 patients), respectively. The positive arterial aneurysm imaging was observed in all patients via computed tomography (CT) or angiography. Eight B. pseudomallei isolates collected from both blood and mycotic aneurysm tissues remained 100% susceptible to imipenem and ceftazidime. After surgery combined with antibiotic administration, six patients survived, with a mortality rate of 25%. In melioidosis endemic areas, the mycotic aneurysm secondary to melioidosis might be underdiagnosed, and increased awareness of predisposing risk factors and clinical features of the mycotic aneurysm is required. Following a positive B. pseudomallei blood culture, the diagnosis of mycotic aneurysm should be under consideration in those with abdominal pain and/or hypertension. Imaging by CT or angiography is indispensable for its timely diagnosis and management.


Assuntos
Aneurisma Infectado/complicações , Aneurisma Infectado/diagnóstico por imagem , Burkholderia pseudomallei/isolamento & purificação , Melioidose/complicações , Melioidose/diagnóstico por imagem , Idoso , Aneurisma Infectado/tratamento farmacológico , Aneurisma Infectado/microbiologia , Burkholderia pseudomallei/efeitos dos fármacos , Burkholderia pseudomallei/genética , Ceftazidima , China , Feminino , Humanos , Imipenem , Masculino , Melioidose/tratamento farmacológico , Melioidose/microbiologia , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Solo , Tomografia Computadorizada por Raios X , Sequenciamento Completo do Genoma
20.
Infect Immun ; 87(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31331957

RESUMO

Burkholderia pseudomallei is the causative agent of melioidosis, a disease endemic to Southeast Asia and northern Australia. Mortality rates in these areas are high even with antimicrobial treatment, and there are few options for effective therapy. Therefore, there is a need to identify antibacterial targets for the development of novel treatments. Cyclophilins are a family of highly conserved enzymes important in multiple cellular processes. Cyclophilins catalyze the cis-trans isomerization of xaa-proline bonds, a rate-limiting step in protein folding which has been shown to be important for bacterial virulence. B. pseudomallei carries a putative cyclophilin B gene, ppiB, the role of which was investigated. A B. pseudomalleiΔppiB (BpsΔppiB) mutant strain demonstrates impaired biofilm formation and reduced motility. Macrophage invasion and survival assays showed that although the BpsΔppiB strain retained the ability to infect macrophages, it had reduced survival and lacked the ability to spread cell to cell, indicating ppiB is essential for B. pseudomallei virulence. This is reflected in the BALB/c mouse infection model, demonstrating the requirement of ppiB for in vivo disease dissemination and progression. Proteomic analysis demonstrates that the loss of PpiB leads to pleiotropic effects, supporting the role of PpiB in maintaining proteome homeostasis. The loss of PpiB leads to decreased abundance of multiple virulence determinants, including flagellar machinery and alterations in type VI secretion system proteins. In addition, the loss of ppiB leads to increased sensitivity toward multiple antibiotics, including meropenem and doxycycline, highlighting ppiB inhibition as a promising antivirulence target to both treat B. pseudomallei infections and increase antibiotic efficacy.


Assuntos
Proteínas de Bactérias/genética , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/patogenicidade , Ciclofilinas/genética , Melioidose/microbiologia , Proteoma/genética , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/classificação , Proteínas de Bactérias/metabolismo , Burkholderia pseudomallei/efeitos dos fármacos , Burkholderia pseudomallei/metabolismo , Linhagem Celular , Ciclofilinas/deficiência , Feminino , Deleção de Genes , Expressão Gênica , Homeostase/genética , Macrófagos/microbiologia , Melioidose/tratamento farmacológico , Melioidose/mortalidade , Melioidose/patologia , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana/efeitos dos fármacos , Proteoma/classificação , Proteoma/metabolismo , Análise de Sobrevida , Virulência
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