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 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.

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.

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 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.

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.

Streptobacillus felis, a member of the oropharynx microbiota of the Felidae, isolated from a tropical rusty-spotted cat.

Streptobacillus felis is a fastidious microorganism and a novel member of the potentially zoonotic bacteria causing rat bite fever. Since its description, this is the second isolation of S. felis in a diseased member of the Felidae. Interestingly, the strain from this study was isolated from a zoo held, rusty-spotted cat (Prionailurus rubiginosus), with pneumonia, thereby indicating a possible broader host range in feline species. A recent preliminary sampling of domestic cats (Felis silvestris forma catus) revealed that this microorganism is common in the oropharynx, suggesting that S. felis is a member of their normal microbiota. Due to unawareness, fastidiousness, antibiotic sensitivity and lack of diagnostics the role of S. felis as a cat and human pathogen might be under-reported as with other Streptobacillus infections. More studies are necessary to elucidate the role of S. felis in domestic cats and other Felidae in order to better estimate its zoonotic potential.

Rat bite fever caused by Streptobacillus moniliformis infection in a Chinese patient.

BACKGROUND: Rat bite fever (RBF), a severe infectious disease, can result from transmission of the pathogen Streptobacillus moniliformis (S. moniliformis) by rat bite. RBF diagnosis can be overlooked. CASE PRESENTATION: We present a case of RBF in a Chinese patient who was infected with S. moniliformis in mainland China. Meta-next generation sequencing (mNGS) was used to identify potential pathogens and detected S. moniliformis genome sequences in the pustular sample in less than 72 h. Then the diagnosis was validated by polymerase chain reaction analysis. Despite having severe RBF with complications, this 54-year-old male patient was successfully cured with penicillin as a result of timely pathogen-based diagnosis. CONCLUSIONS: Physicians should inquire about recent rat exposure and consider the possibility of RBF when a patient develops unexplained fever and rashes. mNGS is a new diagnostic technology and may identify RBF pathogens even when blood culture results are negative.

Rat-Bite Fever in Human with Streptobacillus notomytis Infection, Japan.

We report a case of rat-bite fever in a 94-year-old woman with Streptobacillus notomytis infection. We established an epidemiologic link between exposure to rats and human infection by performing nested PCRs that detected S. notomytis in the intraoral swab specimens obtained from rats captured in the patient's house.

Clinical infection in house rats (Rattus rattus) caused by Streptobacillus notomytis.

Rat bite fever is an under-reported, under-diagnosed emerging zoonosis with worldwide distribution. Besides Spirillum minus, Streptobacillus moniliformis is the major causative microorganism although it usually colonises rats without any clinical signs. A group of house rats (Rattus rattus) kept in a zoo exhibition for educational purposes suffered from neurological signs including disorientation, torticollis, stall walking, ataxia and death. Gross pathological and histo-pathological examinations of the investigated rats revealed high-grade otitis interna et media, from which Streptobacillus notomytis was isolated in pure culture or as the predominant microorganism. This case series underlines a previously expressed hypothesis that R. rattus might be naturally colonised with S. notomytis, whereas the traditional rat bite fever organism, S. moniliformis, might be restricted to the Norway rat (Rattus norvegicus). However, the general paucity of Streptobacillus isolates, especially from their respective animal hosts, precludes definitive proof of these host tropisms. This is the first report of S. notomytis detection outside Asia and Australia and the first evidence for its role as a facultative pathogen in house rats.

Rat-bite fever due to Streptobacillus notomytis isolated from a human specimen.

Rat-bite fever (RBF) is a disease that usually presents with fever, arthralgia and skin rash. Streptobacillus moniliformis was considered the main cause of RBF among the genus Streptobacillus. Although with similar clinical presentation, RBF due to Streptobacillus notomytis is unusual in humans. To the best of our knowledge, we present a case involving the first isolate of S. notomytis in humans. A 63-year-old woman was admitted to our hospital with fever, rash and polyarthritis. She recalled being bitten by a rat on her finger 5 days before presentation. Clinical manifestations were compatible with rat-bite fever (RBF) and the diagnosis was confirmed by the detection of Streptobacillus species from both blood and pustule samples. Initial polymerase chain reaction tests revealed that the organism was S. moniliformis. However, thorough genetic analysis revealed the organism to be S. notomytis. The condition was successfully treated with ampicillin.

[Infections after bite wounds : For example rat bite fever due to Streptobacillus moniliformis]. / Infektionen nach Bissverletzungen : Zum Beispiel Rattenbissfieber durch Streptobacillus moniliformis.

Rat bite fever due to Streptobacillus moniliformis induces typical but not pathognomonic clinical signs, such as local purulent wound infection followed by maculopapular exanthema, myalgia as well as purulent joint infections. Severe complications, such as osteomyelitis and endocarditis are possible. it seems that this infection is rarely diagnosed but this infection could be much more common because the final diagnostic proof is difficult to achieve. Firstly, the culture of these bacteria is critical because the bacteria are fastidious and secondly the exact differentiation of the isolates is hardly possible by standard laboratory methods. Modern techniques such as mass spectroscopy (MALDI-TOF) and molecular biology allow a precise clarification. Surgical cleansing of infection sites in combination with a rational antibiotic therapy, for example with beta-lactam antibiotics, are generally able to cure the infection if treatment is started early enough. In addition, vaccinations, for example against tetanus and rabies have to be considered in this situation as for all other bite wound infections.

Acute Tetraplegia Caused by Rat Bite Fever in Snake Keeper and Transmission of Streptobacillus moniliformis.

We report acute tetraplegia caused by rat bite fever in a 59-year old man (snake keeper) and transmission of Streptobacillus moniliformis. We found an identical characteristic bacterial pattern in rat and human samples, which validated genotyping-based evidence for infection with the same strain, and identified diagnostic difficulties concerning infection with this microorganism.

Rat-bite fever complicated by vertebral osteomyelitis: A case report.

Rat-bite fever (RBF) is a challenging diagnosis transmitted by the bite of the rats. We present the first reported case of RBF complicated by vertebral osteomyelitis. It is important to consider performing the MRI to differentiate vertebral osteomyelitis from simple back pain to determine the appropriate duration of antibiotic therapy.

A Japanese patient with a rare case of Streptobacillus moniliformis bacteremia.

Streptobacillus moniliformis is the etiological agent of rat-bite fever, a rare disease in Asia that is difficult to diagnose. We describe an elderly patient living in rat-infested conditions who presented with severe sepsis. He was successfully treated with meropenem, and blood culture revealed infection with S. moniliformis.

A rare case of Streptobacillus moniliformis epidural abscess requiring neurosurgical decompression.

Background: Streptobacillus moniliformis is the primary causative agent of rat bite fever, an infectious disease transmitted through contact with rats through bites, scratches, or exposure to excrement. Before this report, only two instances of spinal epidural abscess (SEA) due to S. moniliformis infection have been documented. We present the case of a 76-year-old male who developed a cervical SEA secondary to S. moniliformis infection, requiring neurosurgical decompression of the spinal cord. Case Description: A 76-year-old male presented to the emergency department with bilateral shoulder and back pain, upper extremity weakness, left hip pain, and left thumb pain. He denied any recent exposure to pets or animals, and the initial workup did not yield the source of the infection. Enhanced magnetic resonance imaging of the cervical spine demonstrated C6-7 discitis/osteomyelitis and an associated ventral SEA, as well as discitis/osteomyelitis of the C2 vertebral body and C5-6 endplates. Subsequently, the patient underwent a C3-7 laminectomy and received a 6-week postoperative course of intravenous ceftriaxone, resulting in complete resolution of the abscess. Blood tests revealed the presence of S. moniliformis, which the patient attributed to potential rat exposure at his workplace. Conclusion: Identification and diagnosis of S. moniliformis infection requires a high index of suspicion. Neurosurgeons should consider this rare pathogen in the differential diagnosis of SEA to facilitate early detection, diagnosis, and surgical intervention, ultimately improving patient outcomes.

Septic arthritis complicating Streptobacillus moniliformis rat bite fever: a case report and review of its pathophysiology and diagnosis.

Rat bite fever is characterized by a clinical triad of symptoms, fever, rash and arthritis. It is transmitted by rodents and mainly due to infection by Streptobacillus moniliformis, a fastidious bacterium carried by Rattus norvegicus. This case report presents the case of a patient who developed septic arthritis and fever after a wild rat bite, with subsequent isolation of S. moniliformis from the joint fluid. Upon reviewing 45 other published case reports of S. moniliformis osteoarticular infections following contact with either a rat or its secretions, it was firstly observed that the rat bite fever clinical triad was incomplete in over half of the cases, mainly because rash was infrequently observed among adult patients. Secondly, the clinical presentation of rat bite fever is quite non-specific and rodent exposure is not mentioned by patients in a third of cases upon admission. Altogether, diagnosing rat bite fever is a significant clinical challenge suggesting that it might be significantly underdiagnosed. In addition to these clinical aspects, no evidence was found supporting immunological mechanisms, as suggested in some literature. Instead, when excluding five improperly performed cultures, S. moniliformis was cultured in 25 reported cases and identified twice by direct PCR sequencing amounting to a detection rate of 90% (n = 27/30) on joint fluids. Cultures should be performed in medium containing yeast extract, complete peptic digest of animal tissue and at least 5% blood. Knowing that S. moniliformis is very sensitive to many antibiotics thereby making the culture negative, direct 16S rRNA gene sequencing on joint fluid is an alternative method in the case of clinical and cytological evidence of osteoarticular infections with sterile culture of joint fluid.

Streptobacillus moniliformis endocarditis: case report and review of literature.

Rat bite fever is a rare infection and sometimes results in complications. This case report describes native mitral valve endocarditis in a 44-year-old male patient caused by Streptobacillus moniliformis. The diagnosis was confirmed by transesophageal echocardiography and blood cultures (BACTEC). The patient was treated with IV crystalline penicillin (6 weeks) and gentamicin (2 weeks). The fundamental importance of a high index of suspicion, interpreting investigations and appropriateness of therapy are highlighted.