Streptobacillus moniliformis and IgM and IgG Immune Response in Patient with Endocarditis1.

We describe a case of endocarditis caused by Streptobacillus moniliformis bacteria, a known cause of rat-bite fever, in a 32-year-old woman with pet rats in Germany. The patient had a strong serologic response, with high IgM and IgG titers. Serologic analysis is a promising tool to identify S. moniliformis bacterial infection.

Rat bite fever caused by Streptobacillus notomytis mimicking pyogenic polyarthritis: A case report.

We report the world's sixth case of rat bite fever caused by Streptobacillus notomytis that mimicked pyogenic polyarthritis and required surgical debridement in combination with prolonged antibiotic therapy. This case report highlights the higher severity of rat bite fever caused by S. notomytis compared to S. moniliformis.

Rat-Bite Fever in a 34-Year-Old Female.

Rat-bite fever (RBF) is a rare systemic infectious disease caused by Streptobacillus moniliformis, Spirillum minus, or Streptobacillus notomytis. As the name implies, the disease is typically transmitted by a rat bite. RBF usually presents as a combination of fever, arthritis, and rash. Definitive diagnosis of RBF may prove difficult, as the responsible bacteria are not easily identified with standard testing. We describe a case of RBF in a 34-year-old female who presented with fever, chills, polyarthralgia, and skin rash following a rat bite. Initial vital signs were remarkable for fever and tachycardia. Physical examination revealed an erythematous vesicular and papular rash involving her extremities, buttocks, and oral mucosa. Blood cultures were negative. A skin biopsy revealed leukocytoclastic vasculitis and was negative for Gram stain. Further analysis using specialized immunohistochemistry and polymerase chain reaction (PCR) identified S. moniliformis. A diagnosis of RBF was made, and the patient was successfully treated with a two-week course of doxycycline.

Rat bite fever mimicking ANCA-associated vasculitis.

Rat bite fever (RBF) is a rare infectious zoonotic disease caused by two bacterial species: the Gram-negative rod Streptobacillus moniliformis and the Gram-negative coiled rod Spirillum minus. The association between RBF and skin vasculitis and arthritis has been observed. The aim of this paper was to present a case of rat-bite fever with symptoms of skin vasculitis and arthritis, associated with high titers of ANCA antibodies and anti-endothelial cell antibodies suggestive of primary vasculitis. The patient was successfully treated with antibiotics and non-steroidal anti-inflammatory drugs, leading to significant improvement. Based on the presented case, we discuss the differential diagnosis of the signs and the role of infection in the induction of ANCA antibodies. We reviewed the English language literature for cases of RBF presenting with symptoms of vasculitis and/or antibody presence. A literature review was performed in PubMed and Google using the keywords "rat bite fever" AND "vasculitis", "systemic vasculitis", "ANCA", "antiendothelial antibodies". No cases of rat-bite fever with the presence of ANCA antibodies or AECA antibodies in its course have been described thus far. Rat bite fever is a rare disease with nonspecific symptoms. In its course, general weakness, intermittent fever, leukocytoclastic vasculitis, and arthritis are reported. To our knowledge, this is the first reported case of ANCA positivity associated with RBF.

A Rodential Reckoning: A Case Report and Systematic Review of Streptobacillary Endocarditis.

Introduction: Endocarditis is a rare, often fatal complication of rat bite fever caused by Streptobacillus moniliformis. Only 39 cases have been reported (including this case) as of 2022. We describe a case and aim to perform this entit's first systematic literature review. Methods: We performed a systematic review in CENTRAL, EMBASE, MEDLINE, SciELO, and LILACS. The terms used were terms used were (but not limited to) rat bite fever, Streptobacillus moniliformis, Spirillum minus, and endocarditis. We included all abstracts and articles with patients with echocardiographic or histologic-proven endocarditis. In case of discordance, a third reviewer was involved. Our protocol was submitted to PROSPERO (CRD42022334092). We also performed searches for studies on the reference list of included articles. Results: We retrieved 108 and included 36 abstracts and articles. A total of 39 patients (including our report) were identified. The mean age was 41.27, and 61.5% were males. The most common findings were fever, murmur, arthralgias, fatigue, splenomegaly, and rash. Underlying heart disease was present in 33%. Exposure to rats was noted in 71.8% of patients, with 56.4% recalling a rat bite. Anemia was seen in 57%, leukocytosis in 52%, and elevated inflammatory markers in 58% that had lab work performed. The mitral valve was most affected, followed by the aortic, tricuspid, and pulmonary valves. Surgical intervention was required in 14 (36%) cases. Of those, 10 required valve replacement. Death was reported in 36% of cases. Unfortunately, the literature available is limited to case series and reports. Conclusion: Our review allows clinicians to suspect better, diagnose, and manage Streptobacillary endocarditis.

Streptobacillus moniliformis right hand abscess and monoarthritis following a rat bite.

Streptobacillus moniliformis is a zoonotic agent associated with rat bites. We present a patient with cellulitis, subcutaneous abscess, and septic mono-arthritis after a rat bite of the right hand. The patient had no systemic features of rat bite fever (RBF). S. moniliformis was cultured from purulent drainage of a thumb abscess. This case illustrates an unusual clinical presentation of streptobacillary infection after a rat bite.

A Rodential Reckoning: A Case Report and Systematic Review of Streptobacillary Endocarditis

ABSTRACT Introduction Endocarditis is a rare, often fatal complication of rat bite fever caused by Streptobacillus moniliformis. Only 39 cases have been reported (including this case) as of 2022. We describe a case and aim to perform this entit's first systematic literature review. Methods We performed a systematic review in CENTRAL, EMBASE, MEDLINE, SciELO, and LILACS. The terms used were terms used were (but not limited to) rat bite fever, Streptobacillus moniliformis, Spirillum minus, and endocarditis. We included all abstracts and articles with patients with echocardiographic or histologic-proven endocarditis. In case of discordance, a third reviewer was involved. Our protocol was submitted to PROSPERO (CRD42022334092). We also performed searches for studies on the reference list of included articles. Results We retrieved 108 and included 36 abstracts and articles. A total of 39 patients (including our report) were identified. The mean age was 41.27, and 61.5% were males. The most common findings were fever, murmur, arthralgias, fatigue, splenomegaly, and rash. Underlying heart disease was present in 33%. Exposure to rats was noted in 71.8% of patients, with 56.4% recalling a rat bite. Anemia was seen in 57%, leukocytosis in 52%, and elevated inflammatory markers in 58% that had lab work performed. The mitral valve was most affected, followed by the aortic, tricuspid, and pulmonary valves. Surgical intervention was required in 14 (36%) cases. Of those, 10 required valve replacement. Death was reported in 36% of cases. Unfortunately, the literature available is limited to case series and reports. Conclusion Our review allows clinicians to suspect better, diagnose, and manage Streptobacillary endocarditis.

Rat bite fever in a patient with human immunodeficiency virus.

The authors report the case of a 45-year-old male with history of human immunodeficiency virus who presented unresponsive and with injuries to his hands after spending a night on a lakeside beach. During his hospitalization, he developed a fever with arthralgias and was initially thought to have calcium pyrophosphate dihydrate crystal deposition disease before a diagnosis of Rat Bite Fever was ultimately discovered. He was successfully treated with six-weeks of ceftriaxone. The authors discuss the epidemiology, diagnosis, treatment, and prognosis of Rat Bite Fever.

Development and validation of a triplex real-time qPCR for sensitive detection and quantification of major rat bite fever pathogen Streptobacillus moniliformis.

Streptobacillus (S.) moniliformis is the most important pathogen causing rat bite fever (RBF) worldwide. This zoonotic pathogen is understudied mainly due to difficulties in culturing S. moniliformis as a fastidious microorganism. Therefore, advances in molecular detection techniques are highly needed, especially with regard to the widespread availability of real-time quantitative (q) PCR in laboratories. In this study, we aimed to develop a qPCR for the identification of Streptobacillus species and quantification of S. moniliformis in clinical samples, especially those derived from tissue samples of animal origin. We optimized a previously described PCR protocol in order to develop a qPCR, which can detect different Streptobacillus species with high specificity and is simultaneously able to quantitate S. moniliformis in different clinical matrices. The qPCR exhibited a limit of detection (LOD) of 21 copies/reaction representing ~4-5 streptobacilli, while the limit of quantification (LOQ) was 2.1 × 103 copies/reaction. It was also more sensitive than conventional PCR by two orders of magnitude and proved to have a substantial agreement (Kappa 0.74) compared to it with a superior detection rate in 374 samples from wild rats, laboratory rats and animals from holdings of wild-trapped rats. To conclude, the qPCR described in this study is an important molecular tool that is able to quantify S. moniliformis in tissue samples of animal origin. It represents a suitable tool for future establishment and evaluation of other molecular assays that are highly needed for a better understanding of epidemiology and pathophysiology of RBF. In experimental studies, it will also be useful for titration purposes since the quantification of the organism using classical plate counting technique is problematic and inaccurate.

Rat bite fever in a total knee arthroplasty: an unusual case of periprosthetic joint infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a serious complication of orthopedic arthroplasty surgery. Rat bite fever is a rare infection with Streptobacillus moniliformis (S. moniliformis). Rat bite fever can lead to serious complications such as pyogenic infection of joints, bacteremia, endocarditis and even death. We hereby present the first case of a patient with a total knee arthroplasty, infected with S. moniliformis, successfully treated by surgical debridement, antibiotics and implant retention (DAIR). CASE PRESENTATION: The patient was a 64-year-old female. S. moniliformis was isolated from blood cultures and an aspirate of the left knee by 16S rRNA gene polymerase chain reaction technique. It was assumed that the S. moniliformis had a systemic origin and secondarily infected the knee due to fever nine days before the onset of symptoms of the knee. The patient was successfully managed with DAIR and intravenous administration of ceftriaxone for six weeks and oral doxycycline for another six weeks. CONCLUSIONS: S. moniliformis is a rare pathogen and is difficult to culture. The 16S rRNA sequencing is helpful in the determination of a causative microorganism in the case of a culture-negative PJI. A DAIR procedure in combination with 12 weeks of antibiotics could successfully treat S. moniliformis prosthetic joint infection.

Rat bite fever: a case report review.

CONTEXT: Rat bite fever is a rare disease with a challenging differential diagnosis. The zoonosis has a potentially lethal course in a vulnerable population (children and low socioeconomic class) and a commonly available standard therapy (penicillin). This case report review outlines common epidemiological and clinical factors to improve clinical awareness and timely response to therapeutic actions. METHODS: A systematic literature review was conducted in the PubMed database looking for English language European case reports of rat bite fever from 2000 to 2021. RESULTS: In 17 out of 20 selected cases, the condition of the index patient was identified as an infectious syndrome. Thanks to the almost omnisensitive susceptibility pattern of Streptobacillus moniliformis, timely antibiotic administration prevented an unfavorable outcome in all these cases. However, in the three remaining cases, the initial diagnoses were arthritis (on autoimmune basis and gout) and viral syndrome. Due to delayed antibiotic administration, one case suffered persistent harm, while the other two cases encountered prolonged illness. CONCLUSION AND RECOMMENDATIONS: Rat bite fever is a diagnosis that can be easily missed from both a clinical and a microbiological point of view. As such, rat bite fever becomes part of the differential diagnosis whenever a patient presents with a fever syndrome after being in contact with rodents. In the case of persistent fever, blood culture sampling should be performed even in the absence of a systemic inflammatory response. A bacterial 16S ribosomal RNA PCR on blood or joint aspiration (cultures) is an even more sensitive diagnostic test. Since most transmissions occurred in a domestic setting, keeping rats as pets cannot be recommended.

Septic Polyarthritis Caused by Streptobacillus moniliformis.

Streptobacillus moniliformis is a pleomorphic, fastidious gram-negative bacillus that colonizes rodent respiratory tracts and causes rat-bite fever in humans. Rat-bite fever is associated with septic arthritis, usually monoarticular or pauciarticular. We report a rare case of polyarticular septic arthritis caused by S. moniliformis; the disease was initially misdiagnosed as inflammatory arthritis.

Rat bite fever due to Streptobacillus notomytis complicated by meningitis and spondylodiscitis: a case report.

BACKGROUND: Only three other cases of rat bite fever caused by Streptobacillus notomytis in humans have been reported since this species was identified in 2015. Data specific to the differences in clinical features and geographic distribution between S. notomytis infection and S. moniliformis infection are scarce. All previous cases of human S. notomytis infection were reported from Japan. This is the first case of S. notomytis infection reported from outside of Japan. CASE PRESENTATION: A 72-year-old Thai woman was admitted to Siriraj Hospital (Bangkok, Thailand)-Thailand's largest university-based national tertiary referral center-in August 2020 with fever, myalgia, and polyarthralgia for 3 days, and gradually decreased consciousness for the past 1 day. Physical examination and laboratory investigations revealed septic arthritis of both knee joints, meningitis, and hepatitis. She was initially misdiagnosed as rheumatoid arthritis in the elderly since the initial investigations were unable to detect a causative pathogen. However, S. notomytis infection was later confirmed by polymerase chain reaction amplification of a part of the 16S rRNA gene and sequencing from synovial fluid. Her clinical course was also complicated by spondylodiscitis and epidural abscess caused by S. notomytis, which was detected from tissue biopsy. Therefore, rat bite fever in this patient manifested as meningitis, septic polyarthritis, hepatitis, and spondylodiscitis. The patient was treated with intravenous ceftriaxone then switched to oral amoxicillin with complete recovery. CONCLUSIONS: The clinical manifestations of S. notomytis infection are similar to those demonstrated in S. moniliformis infection. This case also showed that arthritis caused by S. notomytis mimics rheumatoid arthritis, and that meningitis and spondylodiscitis are potential coexisting complications that can be found in S. notomytis infection.

Rat-bite fever: Taking the bite out of a textbook case of Streptobacillus moniliformis blood stream infection.

Increasing popularity of rats as domestic pets and continued use of rodents in scientific laboratories has contributed to a notable increase in reported cases of rat-bite fever caused by Streptobacillus moniliformis in the United States. S. moniliformis is a gram-negative filamentous bacterium that is a commensal bacterium found in the nasopharyngeal tract of rats. This is a case of a young male developing rat-bite fever bacteremia without a known bite from a rat, but with incidental contact with oral secretions. The patient developed significant debilitating symptoms including migratory polymyalgias and demonstrated complete recovery after treatment with ceftriaxone.

Rat bite fever with osteomyelitis and discitis: case report and literature review.

BACKGROUND: Rat bite fever (RBF) is a rare systemic febrile illness transmitted by rats. Streptobacillus moniliformis is a pleomorphic Gram-negative bacillus which is the usual etiologic organism for rat bite fever in the United States. CASE PRESENTATION: Here we present a case of rat bite fever complicated by vertebral osteomyelitis and discitis. The patient revealed an exposure history of being bitten by pet rats. The patient's symptoms dramatically improved with a six-week course of cephalexin therapy. CONCLUSIONS: It is important to obtain a thorough zoonotic exposure history and maintain rat bite fever in the differential when considering potential causes of discitis and osteomyelitis.

Using the BDFX40 Automated Continuous Blood Culture System to Isolate and Recover Streptobacillus moniliformis in the Presence of 0.05% SPS: A 55-Year, 56-Strain Retrospective Study.

Rat bite fever and Haverhill fever are often difficult to diagnose in a clinical setting. This difficulty results in part from clinicians and laboratory professionals not being able to reliably recover the causative agent Streptobacillus moniliformis using culture-based methods. After utilizing an automated continuous-monitoring blood culture bottle system, we showed that the organism can be reliably cultured when a blood volume inoculum of 10 mL is used. Further, we showed that when the above recommendation is followed, sodium polyanethole sulfonate (up to a concentration of 0.05% w/v) in commercially purchased blood culture bottle formulations seems to be inactivated, allowing for the growth and detection of S. moniliformis. Herein, we offer data and methods used to overcome these clinical limitations. This is a comprehensive study of the historical collection of S. moniliformis isolates maintained by our facility and believed to be the largest of its kind to date.

A real-time multiplex PCR assay for detection of the causative agents of rat bite fever, Streptobacillus moniliformis and zoonoticStreptobacillus species.

Rat bite fever (RBF) caused by Streptobacillus moniliformis has been described as a diagnostic challenge. While it has a favorable prognosis with treatment, timely diagnosis is hindered by the lack of culture-free identification methods. Here we present a multiplex real-time PCR assay that detects the zoonotic Streptobacillus spp. as well as differentiate the primary causative agent of RBF, Streptobacillus moniliformis. The performance of this assay was evaluated using mock clinical specimens for blood, serum, and urine. Analytical sensitivity was determined to be 3-4 genome equivalents (GE)/µl for the zoonotic Streptobacillus spp. target, and 1-2 GE/µl for the S. moniliformis specific target. The assay correctly detected only the intended targets with no cross-reactivity identified. The pathogen was detected in all spiked matrices and not detected in the negative non-spiked specimens. This rapid diagnostic assay may permit quicker diagnosis of RBF patients.

Infection in a Young Immunocompetent Male Caused by Streptobacillus felis, a Putative Zoonotic Microorganism Transmitted by Cats.

Rat bite fever (RBF) is predominantly caused by Streptobacillus moniliformis. We report a human infection with Streptobacillus felis. Clinical presentation was consistent with RBF, but serologic testing was negative for S moniliformis. Eventually, S felis-specific sequences were detected in skin lesions of the patient and in the oropharynx of local cats.

Erosive polyarthritis caused by sepsis due to a novel species of Streptobacillus notomytis.

Rat-bite fever (RBF) is characterized by fever, rash and arthritis, mainly caused by Streptobacillus moniliformis. We present a case of inflammatory erosive polyarthritis with sepsis caused by Streptobacillus notomytis, a novel species isolated from S. moniliformis. A 67-year-old man presented with fever, purpura and peripheral arthritis. After blood cultures were performed, loxoprofen administration was initiated. Arthritis partially improved, but left first metatarsophalangeal (MTP) arthritis persisted. A gram-negative rod was detected in the blood culture, and meropenem administration was started that improved arthritis. Ultrasonography and computed tomography revealed bone erosion in the left first MTP joint, leading to the diagnosis of septic arthritis. 16S rRNA gene sequence analysis revealed that this strain was S. notomytis. Further questioning revealed the patient may have had contact with rats. It is essential to consider Streptobacillus infection in the differential diagnosis of erosive polyarthritis.