A case of disseminated infection caused by Streptococcus equi subspecies zooepidemicus

A Rare Case of Streptococcus equi Subspecies Zooepidemicus Bacteremia

Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen that primarily infects horses, pigs, and dogs. Although rare, it has also been shown to infect humans who consume unpasteurized dairy food or have direct contact with horses. Here, we present a case of S. zooepidemicus bacteremia in a patient without a clear mode of transmission. An 86-year-old male with a past medical history of coronary artery disease, heart failure with reduced ejection fraction, complete heart block status post pacemaker, hypertension, hyperlipidemia, and type 2 diabetes mellitus presented to the Emergency Department with fever and chills. He had fevers and rigors for three days but denied weight loss, cough, sore throat, or rashes. In the Emergency Department, vital signs revealed a fever of 101.2 degrees Fahrenheit and a heart rate of 110 with other stable vital signs. The physical exam was unremarkable except for tachycardia, and laboratory work revealed no leukocytosis but elevated inflammatory markers and elevated lactate. Computed tomography of the chest, abdomen, and pelvis did not reveal any source of infection. Blood cultures grew S. zooepidemicus and the Infectious Diseases team was consulted, who started the patient on Penicillin G. Due to concern for pacer-lead infective endocarditis, transthoracic and transesophageal echocardiograms were performed, which did not show valvular vegetations. Repeat blood cultures showed clearance of the infection, and the patient was ultimately discharged on amoxicillin. While our patient denied consuming unpasteurized dairy products or having direct contact with horses, upon further questioning, he did endorse family members who occasionally interacted with horses. This case is valuable as it adds to the sparse literature on S. zooepidemicus infections specifically in humans. Extensive history taking is of utmost importance when a clear source of infection is not easily identifiable. Further research is also needed to better understand the various modes of transmission of this bacterium to better target and caution those at an increased risk of infection.

Horse to human: Streptococcus equi septicemia presenting as endogenous endophthalmitis

Purpose

To present a rarely reported systemic infection with streptococcus equi subspecies zooepidemicus (streptococcus equi), transmitted from a horse, and to describe successful treatment when complicated by endogenous endophthalmitis.

Observations

We diagnosed suspected streptococcus equi septicemia presenting as loss of vision in the right eye of an otherwise healthy polo player/horse trainer. He received immediate intravenous antibiotics and three vitrectomies with two intravitreal antibiotic injections during the first week, to cure infection and subsequent retinal detachment. Blood and initial vitreous cultures rapidly grew streptococcus equi. The septicemia was quickly controlled by systemic antibiotics without developing commonly seen and often fatal meningitis. The right eye recovered 20/30 visual acuity three months post infection.

Conclusions

Presentation of this rare septicemia as endogenous endophthalmitis illustrates the potentially lifesaving role of early diagnosis by the ophthalmologist. Immediate and recurrent vitrectomy in conjunction with intravitreal and systemic antibiotic therapy resulted in recovery of near normal vision, whereas less timely and interventional treatments have failed heretofore.

Streptococcus zooepidemicus Meningitis in an HIV-Positive Horse Breeder Patient: A Case Study and Literature Review

Streptococcus equi subsp. zooepidemicus is a rare etiologic agent of bacterial meningitis in humans. The disease is a zoonotic infection and is transmitted through close contact with domestic animals, mainly horses. Only 37 cases of Streptococcus zooepidemicus meningitis have been reported in the literature until July 2023. The aim of this study is to present a rare clinical case of S. zooepidemicus-related meningitis in a human immunodeficiency virus (HIV)-positive patient and analyze the literature. We present a 23-year-old horse breeder patient with advanced immunosuppression due to acquired immunodeficiency syndrome (AIDS) and S. zooepidemicus meningitis, admitted at the Clinic of Infectious Diseases, St. George University Hospital, Plovdiv. The course of meningitis was severe since the beginning, with significant cerebral edema, disturbances in consciousness, persistent fever, and the development of complications against the background of AIDS-related conditions. S. zooepidemicus was microbiologically detected from cerebrospinal fluid culture. After prolonged treatment and a long hospital stay, the patient's condition improved, and eventually he was discharged and recovered from the acute neuroinfection. Although extremely rare, S. zooepidemicus should be considered in patients with clinical and laboratory evidence of bacterial meningitis who have contact with animals, especially horses, other domestic animals, and their dairy products, as well as in immunocompromised patients. To the best of our knowledge, the current clinical case is the first report of S. zooepidemicus-related meningitis in a patient with HIV/AIDS.

A case of bacteremia and pneumonia caused by Streptococcus equi subspecies equi infection in a 70-year-old female following horse exposure in rural Wyoming

BACKGROUND

The occurrence of zoonotic infections following an animal exposure continues to be an important consideration for all patients, especially those within agricultural communities. Streptococcus equi subspecies equi (S. equi subsp. equi) is a bacteria known to cause a common infection called 'Strangles' in horses. This article highlights a new case of pneumonia and bacteremia in a patient caused by S. equi subsp. equi following strangles exposure in a horse. Rarely has there been reported horse to human transmission of subsp. equi.

CASE PRESENTATION

A 70-year-old woman attended a rural emergency department with complaints of dry heaving, fever, chills, shakes, and nausea and presented with a cough. She had undergone a screening colonoscopy two days prior with no other significant medical history. The patient had computed tomography (CT) evidence of a pneumonia and positive blood cultures growing S. equi subsp. equi consistent with bacteremia. The patient later disclosed the recent passing of her horse following its sudden illness six days prior to her emergency department presentation. She had cuddled and kissed the horse prior to its death. The patient was treated with IV lactated ringers during the initial evaluation and admission and also received IV piperacillin-tazobactam 4.5 g every eight hours intravenously during her hospital stay. She was transitioned to an oral antibiotic on discharge. Subsequent blood cultures drawn the day after discharge were negative for S. equi subsp. equi, indicating successful treatment of her bacteremia.

CONCLUSIONS

This report discusses an atypical presentation of S. equi subsp. equi infection in an otherwise healthy individual, manifesting as early sepsis, pneumonia, and bacteremia. The patient likely developed this infection following direct contact exposure to her horse who had died from presumed strangles a few days prior to her symptom onset. This case highlights the importance of investigating potential exposures to S. equi subsp. equi in rural areas, areas where farming and ranching are prevalent, particularly among individuals working with horses. It is especially important to acknowledge high risk populations such as immunocompromised individuals with signs and symptoms of meningitis or bacteremia.

Human zoonotic infectious disease caused by Streptococcus equi subsp. zooepidemicus

Streptococcus equi subsp. zooepidemicus (SEZ) is a highly contagious infectious organism that causes disease in horses. SEZ is seldom isolated from humans; however, zoonotic infections are occasionally reported in individuals exposed to horses and other livestock. Herein, we report three human cases of SEZ in individuals, one with direct horse contact and two among individuals who had eaten raw horse meat. The phylogenetic tree showed that the genotypes of SEZ isolates from two of the cases on Jeju Island, South Korea, were similar to those of isolates from the United Kingdom and the United States of America.

Streptococcus equi subspecies zooepidemicus Meningitis, Septicemia, and Brain Infarcts in a Costa Rican Infant

Streptococcus equi, an equine commensal bacterium, is a rare etiology of septicemia and meningoencephalitis in humans and is extremely infrequent in children. Scarce literature has been published about its clinical presentation, treatment and outcomes in infants. Here, we describe a case of S. equi subsp. zooepidemicus septicemia and meningoencephalitis in a five-month-old Costa Rican infant that was confirmed by peripheral blood and cerebrospinal fluid (CSF) cultures in a regional hospital of the Pacific coast of Costa Rica who developed multiple ischemic cerebral infarcts secondary to infectious vasculitis, a subdural empyema and serious neurological sequelae. We also reviewed the literature on S. equi meningitis in infants under one year of age. This is the first reported case in our country, the fourth reported in infants under one year of age and the second describing multiple cerebral infarcts and subdural empyema in an infant.

Infected Aortic Aneurysm Caused by Streptococcus zooepidemicus: A Case Report and Literature Review

A 66-year-old Japanese male working at a stable developed abdominal pain and fever and was brought to the emergency department. The computed tomography scan revealed an aneurysm of approximately 70 mm in diameter, with an irregular border, at the infrarenal abdominal aorta. Emergency surgery was performed with a bifurcated Dacron graft. Streptococcus zooepidemicus was observed on the aneurysm wall. He was discharged in good condition and was prescribed oral amoxicillin/clavulanic acid for 4 months. He has remained well and did not develop inflammation. Evaluation of patient history and data, including the consumption of unpasteurized dairy food, occupation, and direct contact with animals, is important for an early diagnosis, a prompt surgery, and an appropriate antibiotic therapy.

Possible canine source of Streptococcus equi subspecies zooepidemicus causing meningitis in an infant

Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a pathogen that colonizes and causes disease in horses, and less commonly, in other mammals. This zoonotic disease in humans is rare. In the reported human cases, it has caused bacteremia, endocarditis, arthritis and meningitis, and it has been linked to contact with horses or ingestion of unpasteurized dairy products.

We report a case of a six-month-old female patient who presented with a one-day history of fevers and neurological symptoms. Blood and cerebrospinal fluid cultures revealed S. zooepidemicus, and brain imaging showed a subdural fluid collection and diffuse brain infarcts. Exposure history suggested a canine source as patient had close contact with two dogs that had respiratory infections but no contact with other pets including horses. She had clinical and radiographic improvement after a four-week course of penicillin G and drainage of a subdural fluid collection but she had residual severe to profound hearing loss and mild neurocognitive deficits. This case report provides the third reported case of possible S. zooepidemicus transmission from dogs to humans, and the second such case that has led to meningitis. Clinicians and public health practitioners should recognize that S. zooepidemicus may be transmitted from dogs and can lead to severe disease in humans.

Streptococcus equi subsp. zooepidemicus and 'Neighbourhood syndrome' -extra-orbitocranial rhinosinusitis with reversible sudden loss of vision- a case report

Background

Rhinosinusitis is a common condition which may present with complications commonly involving the orbit and the intracranial space. Loss of vision in the absence of clinical or radiological signs of involvement of the orbit and intracranium is rare and carries a high morbidity rate. Streptococcus equi subspecies zooepidemicus is not a well-documented cause of paranasal sinus infection.

Case presentation

We present a case of a 16 year old female patient who had unilateral loss of vision with signs of retrobulbar optic neuritis and no other neurological signs. We isolated an unusual organism- Streptococcus equi subspecies zooepidemicus from the maxillary sinus. Emergency endoscopic sinus surgery and antibiotic treatment resulted in complete reversal of the loss of vision.

Conclusion

The presence of paranasal sinus disease in association with loss of vision even in the absence of a clear link between the two should be treated as an emergency with surgical drainage and or appropriate antibiotic therapy. In patients presenting with suspected inflammatory orbital involvement, imaging of the orbit and paranasal sinuses should be considered early.

Denaturing Gradient Gel Electrophoresis Analysis of Bacteria in Italian Ticks and First Detection of Streptococcus equi in Rhipicephalus bursa from the Lazio Region

Tick-borne diseases are an increasing problem for the community. Ticks harbor a complex microbial population acquired while feeding on a variety of animals. Profiling the bacterial population by 16S rDNA amplification and denaturing gradient gel electrophoresis enables detection of the broad spectrum of bacteria that settles in the ticks. This study identified known and unknown tick-infecting bacteria in samples from Italy. Seven adult ticks from different hosts and origins were analyzed: two Rhipicephalus sanguineus ticks from dogs (Lombardia), two Rhipicephalus bursa ticks from bovines (Lazio), and three Ixodes ricinus ticks from humans (Marche). The major result was the first report of the zoonotic agent Streptococcus equi in ticks. S. equi is a species complex of highly contagious pathogens. Subsequent to S. equi detection in a R. bursa tick removed from a bovine of Lazio in 2012, we studied 95 R. bursa samples collected from 3 bovines, 3 ponies, and 1 sheep grazing in the same area in 2012 and from 6 ponies grazing there in 2017. The results of a specific PCR assay indicated a not sporadic occurrence of S. equi in ticks. This finding provides a basis for assessing the potential of ticks to harbor and disperse S. equi.

Infective endocarditis due to Streptococcus dysgalactiae: clinical presentation and microbiological features

Knowledge of infective endocarditis (IE) caused by Streptococcus dysgalactiae (SD) is limited. This study aimed to identify the clinical and microbiological features of SD-caused IE and to investigate any possible synergy between penicillin and gentamicin on SD isolates. Cases of IE 2008-2016 due to SD reported to the Swedish Registry of Infective Endocarditis (SRIE) were identified. Isolates were emm typed and synergy between antibiotics was determined in time-kill experiments. Medical records were reviewed and SD-cases were compared to cases of IE due to other pathogens reported to the SRIE. Fifty cases of SD-caused IE were confirmed. emm types stC74a, stG62647, and stG643 were most commonly encountered. The patients had a median age of 74 years (range 38-93) and were significantly older compared to patients with Staphylococcus aureus-caused IE, (65 years (p = 0.003)). The median time to diagnosis from symptom onset was 1 day for patients with SD-caused IE which was less compared to patients with IE due to the other pathogens (2-15 days). Embolization was seen in 46% and the in-hospital mortality was 8%. Etest-based methods did not indicate any synergy between penicillin and gentamicin whereas synergy was noted for four out of nine isolates applying time-kill assays. This is the largest study of SD-caused IE, a condition with an acute onset predominantly affecting elderly people. Synergy between penicillin and gentamicin against some SD isolates was distinguished but the potential benefit of this must be weighed against the risk of aminoglycoside side effects.

Sepsis, Endocarditis, and Purulent Arthritis due to a Rare Zoonotic Infection with Streptococcus equi Subspecies zooepidemicus

Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is mostly known as an opportunistic pathogen found in horses and as a rare human zoonosis. An 82-year-old male, who had daily contact with horses, was admitted in a septic condition. The patient presented with dyspnea, hemoptysis, impaired general condition, and severe pain in a swollen left shoulder. Synovial fluid from the affected joint and blood cultures showed growth of S. equi subsp. zooepidemicus. Transesophageal echocardiography showed a vegetation on the aortic valve consistent with endocarditis. Arthroscopic revision revealed synovitis and erosion of the rotator cuff. Technetium-99m scintigraphy showed intense increased activity in the left shoulder, suspicious of osteitis. The infection was treated with intravenous antibiotics over a period of five weeks, followed by oral antibiotics for another two months. The patient recovered without permanent sequelae.

Polyarthritis in Goat-Kids Caused by Streptococcus Equi Subspecies Zooepidemicus

Infectious arthritides in goats is mainly caused by mycoplasmas and Caprine Arthritis- Encephalitis virus (CAEV). Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a member of Lancefield group C beta-hemolytic streptococcus that commonly colonizes the mucous membranes of healthy equids which is also capable to induce different pathological conditions in many animal species. In this paper we described a case of polyarthritis in four Alpine goat-kids caused by S. zooepidemicus. Goat-kids originated from a farm where sheep, llamas, shepherd dogs, cows and horses were kept with goats. During the external examination of carcasses, crusts and discrete hyperemia were seen on the earlobes beneath the ear tag, as well as swollen joints. Necropsy findings included severe fibrinous polyarthritis in all four examined kids. Shoulder, knee and hip joints were affected. From all affected joints S. zooepidemicus was isolated. Neither Mycoplasma spp. nor CAEV genome were detected from the affected joints. Most likely the goatkids were infected with S. zooepidemicus through the lesions on earlobes which were made after the tagging. As a possible source of bacteria, we recognized the horses and dogs. Due to the lack of any signs of illness in other animal species on the farm, as well as negative pathomorphological findings in other organs, we assumed that the isolated strain is highly adapted to goat-kids. Our report is the first described case of polyarthritis in goat-kids caused by S. zooepidemicus.

Endogenous endophthalmitis complicating Streptococcus equi subspecies zooepidemicus meningitis: a case report

Background

Streptococcus equi subspecies zooepidemicus (Streptococcus zooepidemicus) is a rare cause of meningitis in humans. Humans mainly get infected by contact with an animal source or by ingestion of unpasteurized dairy products. In rare cases, bacterial meningitis can be complicated by endogenous endophthalmitis which is frequently associated with a poor visual prognosis.

Case presentation

A 73 year old male Caucasian patient presented with clinical signs indicative of bacterial meningitis. Blood and cerebrospinal fluid cultures yielded beta-hemolytic, catalase-negative cocci. The strain was identified as Streptococcus zooepidemicus. The patient was likely infected by contact with a sick horse. Under antibiotic treatment, his general condition improved rapidly. Early after hospital admission, however, he began seeing a black spot in his left eye’s central visual field. An ophthalmological examination revealed signs of endogenous endophthalmitis and so the patient underwent vitrectomy. Despite treatment, the visual acuity of his left eye remained severely impaired. He showed no further neurological deficits at hospital discharge.

Conclusion

Meningitis caused by Streptococcus zooepidemicus is rare with only 27 previously published adult cases in the literature. Of note, this report constitutes the third description of endogenous endophthalmitis associated with Streptococcus zooepidemicus meningitis. Thus, endogenous endophthalmitis may represent a comparatively common complication of meningitis caused by this microorganism.

Draft Genome Sequence of Streptococcus equi subsp. zooepidemicus Strain S31A1, Isolated from Equine Infectious Endometritis

We present the draft genome sequence of Streptococcus equi subsp. zooepidemicus S31A1, a strain isolated from equine infectious endometritis in Denmark. Comparative analyses of this genome were done with four published reference genomes: S. zooepidemicus strains MGCS10565, ATCC 35246, and H70 and S. equi subsp. equi strain 4047.

Streptococcus group C meningitis with cavernous sinus thrombosis

Group C Streptococcus (GCS) is a rare cause of bacteremia in humans. It is mostly associated with zoonological infections. Although GCS can be part of the normal oral, skin, and genitourinary fora, an infection with this pathogen can be highly virulent, causing rapid, disseminating disease. With a mortality of about 25%, the poor prognosis is linked to the severity of illness and the high level of virulence of the organism. Only a few cases of GCS meningitis have been reported. We present the first case of GCS meningitis with cavernous sinus thrombosis.

Scientific Opinion on the public health hazards to be covered by inspection of meat from sheep and goats

A risk ranking process identified Toxoplasma gondii and pathogenic verocytotoxin-producing Escherichia coli (VTEC) as the most relevant biological hazards for meat inspection of sheep and goats. As these are not detected by traditional meat inspection, a meat safety assurance system using risk-based interventions was proposed. Further studies are required on T. gondii and pathogenic VTEC. If new information confirms these hazards as a high risk to public health from meat from sheep or goats, setting targets at carcass level should be considered. Other elements of the system are risk-categorisation of flocks/herds based on improved Food Chain Information (FCI), classification of abattoirs according to their capability to reduce faecal contamination, and use of improved process hygiene criteria. It is proposed to omit palpation and incision from post-mortem inspection in animals subjected to routine slaughter. For chemical hazards, dioxins and dioxin-like polychlorinated biphenyls were ranked as being of high potential concern. Monitoring programmes for chemical hazards should be more flexible and based on the risk of occurrence, taking into account FCI, which should be expanded to reflect the extensive production systems used, and the ranking of chemical substances, which should be regularly updated and include new hazards. Control programmes across the food chain, national residue control plans, feed control and monitoring of environmental contaminants should be better integrated. Meat inspection is a valuable tool for surveillance and monitoring of animal health and welfare conditions. Omission of palpation and incision would reduce detection effectiveness for tuberculosis and fasciolosis at animal level. Surveillance of tuberculosis at the slaughterhouse in small ruminants should be improved and encouraged, as this is in practice the only surveillance system available. Extended use of FCI could compensate for some, but not all, the information on animal health and welfare lost if only visual post-mortem inspection is applied.

Co-infection of Ornithobacterium rhinotracheale with Streptococcus zooepidemicus in chickens

An outbreak of bronchial embolization with 50%-70% morbidity and 30% mortality occurred in broilers in northeast China. This highly contagious disease is characterized by the sudden onset of clinical symptoms, including dyspnea, hemorrhagic tracheal discharge, and bronchial obstruction. Subsequently, six strains of Ornithobacterium rhinotracheale (ORT) and three strains of Streptococcus zooepidemicus were isolated from the various organs and identified using biochemical tests and PCR methods. The pathogenesis of embolization in chickens is poorly understood. The current experimental study confirmed that ORT infection alone could induce a significantly fatal hemorrhagic pneumonia and high mortality in comparison with S. zooepidemicus infection. Moreover, co-infection of ORT with S. zooepidemicus could induce even higher mortality, with severe bronchial obstruction, than that observed in chickens infected with S. zooepidemicus or ORT alone. Therefore, the combination of ORT and S. zooepidemicus may be associated with the outbreak of chicken bronchial embolization. Further investigation of the pathogenesis of ORT and Streptococcus is urgently needed.

Identification of a surface protective antigen, CSP of Streptococcus equi ssp. zooepidemicus

Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) is an important pathogen associated with opportunistic infections of a wide range of species, including horses, pigs and humans. The absence of suitable vaccine confounds the control of SEZ infection. Cell surface protein (CSP) has been identified as an immunogenic protein in the previous study but its protective efficacy is not clear. In the present study, the purified recombinant CSP could elicit a significant humoral antibody response and could confer significant protection against challenge with lethal dose of SEZ in mice model. CSP could adhere to the HEp-2 cells confirmed by flow cytometry and inhibit adherence of SEZ to HEp-2 cells in an adherence inhibition assay. In addition, real-time PCR demonstrated that CSP was induced in vivo following infection of mice with SEZ. Our findings suggest that CSP may play a potential role in the pathogenesis of SEZ and could be a target for the development of a novel subunit vaccine against SEZ infection.