Suis Infections In Humans Research Articles

Emergence of Streptococcus suis infection from Goa, India

Abstract Streptococcus suis is an emerging zoonotic bacterium that causes severe invasive disease in humans. In India, only two human case reports have been recorded till now. In the present report, we described the clinical case report along with an epidemiological investigation of the first S. suis case from Goa, India. The clinical presentation and detailed history regarding the potential exposure factors for the infection were recorded and to trace the source of the infection, the meat markets and the backyard piggeries in the vicinity of the patient’s residence were investigated. Case definitions were formulated and enhanced surveillance was initiated in the State to identify any additional cases. The case-patient was a co-morbid 63-year-old female, who was provisionally diagnosed with meningitis and septicaemia and S . suis infection was detected using automated microbial identification systems. The epidemiological investigation revealed that the patient was involved in handling raw pork one day prior to the symptom onset. Based on the active case finding, no additional case of S. suis was detected in the area. The present case was a sporadic case of S. suis in Goa, India and case-patient may have been exposed to the bacteria by handling raw pork while cooking. One Health impact statement Our investigation described the 3rd case of Streptococcous suis from India. This is significant because despite the abundance of the source of infection across the country i.e. high prevalence in the pig population, there are unusually low number of human cases, which can be attributed to very low clinical index of suspicion and lack of diagnostic tests in humans, as evidenced in the present case. A multi-disciplinary One Health approach has been applied for the present case investigation as the Human Health, Animal Health and Food Safety aspects were investigated in collaboration with the State Health & Animal Husbandry departments along with the academia. The findings of the present investigation will aid in enhancing the clinical index of suspicion among clinicians and awareness among high-risk groups like veterinarians for S. suis infection in humans and animals. The multi-disciplinary One Health approach aided us in tracing the source of the infection, which would help in generating evidence for designing preventive interventions.

Occupational Hazards: The Impact of Streptococcus suis Infections in Portuguese Pig Farming

Abstract Background In Portugal, the commensal and opportunistic bacteria Streptococcus suis is prevalent among pigs. Recognizing its public health significance, this systematic review investigates the relationship between occupational exposure in pig farming and the incidence of S. suis infections among workers. The importance of this study is to identify high-risk occupational activities and formulate effective public health interventions. Methods This review analyzed 20 scientific studies from 1986 to 2023 on human infections with S. suis in Portugal. The primary sources included articles in Portuguese from databases like MedLine, Scopus, and Pubmed. Studies were selected based on their focus on occupational exposure and the details provided on epidemiological context, clinical presentations, and outcomes. Results The review found that 85% of infection cases occurred in occupational settings, particularly among butchers (53%) and pig breeders or handlers (29%). Clinical manifestations predominantly included acute bacterial meningitis, with significant occurrences of neurosensory hearing loss as a sequelae. The average age of affected individuals was 44, predominantly male. Conclusions The study confirms a significant correlation between occupational exposure in pig farming and S. suis infections in humans. The findings underscore the need for stringent occupational health measures and integrated approaches encompassing human, animal, and environmental health under the One Health initiative. Innovations in public health interventions recommended include enhanced surveillance, improved workplace hygiene, and targeted health education for at-risk populations. Key messages • Occupational exposure in pig farming is a significant risk factor for S. suis infections in humans. • Integrative One Health approaches are essential for preventing S. suis infections in occupational settings.

Identification and genomic analyses of a Streptococcus suis ST25 strain associated with the first human septicemia in mainland China

Streptococcus suis (S. suis) is a Gram-positive bacterium and the main culprit behind zoonotic outbreaks, posing a serious threat to public health. The prevalent strains in China are mainly of sequence types (ST) 1 and 7, with few cases of human infections caused by other sequence type being reported. This study presents the first isolation of a ST25 strain from the blood of a septicemic patient. A 57-year-old febrile patient was admitted to a hospital in Hainan of China, diagnosed as septicemia and hepatic dysfunction. A strain of S. suis was isolated from blood culture and confirmed to be serotype 2 and ST25 through 16S rRNA sequencing and whole-genome sequencing, and its genome was further analyzed for gene functions and presence of drug resistance genes. The full-length genome of strain HN28 spans 2,280,124 bp and encodes a total of 2291 proteins. Genes annotated in COG, GO, KEGG, CAZy, and PHl databases accounted for 75.38 %, 69.14 %, 55.35 %, 4.58 %, and 11.87 % of the total predicted proteins, respectively. Virulence factor analysis revealed the presence of seven putative virulence genes in strain HN28. Analysis using the CARD database identified 51 resistance genes in HN28, alongside abundant exocytosis systems. These findings underscore the occurrence of S. suis infections in humans caused by less common ST, emphasizing the need for enhanced epidemiological investigations and monitoring of S. suis infections in the human population.

Contamination of Streptococcus suis and S. suis Serotype 2 in Raw Pork and Edible Pig Organs: A Public Health Concern in Chiang Mai, Thailand.

Streptococcus suis is one of the most important zoonotic pathogens causing serious diseases in both pigs and humans, especially serotype 2. In northern Thailand, there is a notable prevalence of S. suis infection in humans and transmission has occurred mainly through the consumption of raw pork products. Despite the continued practice of consuming raw pork in this region, limited data exist regarding S. suis contamination in such products. Therefore, this study aimed to assess the prevalence of S. suis and S. suis serotype 2 in retail raw pork meat and edible pig organs sold in Chiang Mai city, Thailand. A total of 200 samples, comprising raw pork meat and edible pig organs, were collected from nine fresh markets in Chiang Mai city between May and July 2023. Samples were prepared and cultured in Todd-Hewitt broth. Bacterial DNA was extracted and tested for any serotypes of S. suis and serotype 2 using loop-mediated isothermal amplification (LAMP) techniques. The study revealed contaminations of S. suis and serotype 2 at rates of 84% and 34%, respectively, with a higher prevalence observed in pig organs compared to raw pork. Both S. suis and serotype 2 were detected across all nine fresh markets investigated. The prevalence of S. suis remained consistently high throughout the study period, whereas serotype 2 showed peaks in May and July. These high rates of contamination indicate that people who consume or work in close contact with raw pork or edible pig organs are at a high risk of S. suis infection. Urgent implementation and maintenance of food safety campaigns and public health interventions are crucial for disease prevention and control.

Antibiotic Susceptibility Pattern of Streptococcus suis Isolate From Clinical Specimens at Sanglah General Hospital, Denpasar, Bali

Background: Streptococcus suis is a gram-positive bacterium that causes emerging zoonotic disease. It causes outbreaks in some countries including China, Vietnam, Thailand, and Indonesia more than 1600 cases worldwide. The recent discovery of cases of S. suis infection is also accompanied by reports of S. suis being resistant to several antibiotics, this can be a recent threat. There are very few reports of susceptibility testing of S. suis in humans, from several studies showed that all were still sensitive to penicillin and ceftriaxone antibiotics but decreased sensitivity to chloramphenicol, clindamycin, and erythromycin. The first case of S. suis infection in humans in Bali was discovered in 2014 and data on antibiotic susceptibility to these bacteria do not available in Indonesia. Therefore, we conducted a study to describe the antimicrobial susceptibility pattern of S. suis isolates in Sanglah General Hospital, Denpasar which can be used as guidance empirical therapy for this bacterial infection. Methods: We obtained 51 data from VITEK 2 GP card automatic system (BioMérieux®) results from April 2016 to April 2021 in Sanglah General Hospital, Denpasar, Bali, Indonesia. Results: The result showed that 51 isolates (100 %) were sensitive to Ampicillin, Cefotaxime, Ceftriaxone, Levofloxacin, Linezolid, and Vancomycin, and 50 (98 %) were sensitive to Benzylpenicillin, 49 (96 %) were sensitive to Erythromycin, 48 (94 %) were sensitive to Clindamycin and none of the isolates (0 %) were sensitive to Tetracycline. Conclusions: All of the isolates from Sanglah General Hospital remain sensitive to antibiotics that cross the blood-brain barriers such as Ceftriaxone, Cefotaxime, and Ampicillin so that the management of S. suis meningitis can be handled precisely which can reduce morbidity and mortality. Proper use of antibiotics in managing S. suis infection can prevent resistance.

The Ability of Nuclease-Resistant RNA Aptamer against Streptococcus suis Serotype 2, Strain P1/7 to Reduce Biofilm Formation In Vitro.

Streptococcus suis, a Gram-positive bacterium, is an important swine and human pathogen, with serotype 2 being the most prevalent strain found worldwide. Deafness, meningitis, and death (in severe cases) are observed in S. suis-infected cases. Development of the ligands that can bind to S. suis with high affinity and specificity could be beneficial for the diagnosis and treatment of S. suis infection. Herein, the nuclease-resistant RNA aptamers based on 2′-fluoropyrimidine modification against S. suis serotype 2, strain P1/7, were established using the cell- Systematic Evolution of Ligands by Exponential enrichment (SELEX) technique. One of the aptamers, R8-su12, could bind to the S. suis target strain as well as other S. suis serotypes, i.e., 1, 1/2, 9, and 14, but not to other bacteria tested, i.e., S. pneumoniae ATCC 49619, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. Moreover, the R8-su12 RNA aptamer was also capable of inhibiting the biofilm formation of the S. suis target strain, making it potentially useful for the study of biofilm formation and the treatment of S. suis infection in humans and pigs in the future.

A large cluster of human infections of Streptococcus suis in Bali, Indonesia

A cluster of 18 inpatients and 21 outpatients with a major complaint of meningitis and a history of sharing traditional delicacies of raw pork and pig blood in a village festival led to the suspicion of Streptococcus suis (S. suis) meningitis in Sibang Kaja Village, Badung, Bali, Indonesia. We conducted an investigation and case finding to prevent human fatalities. Demography and laboratory examinations of the inpatients were recorded. Bacterial culture, identification, and sensitivity tests were conducted using a VITEK 2 Compact machine (Biomeriuex®) with cerebrospinal fluid (CSF) or blood from the inpatients. The bacterial species were confirmed via PCR. A subsequent investigation was also conducted to identify the source of the meat, the presence of S. suis in slaughtered pigs, and the zoosanitary measures at pig farms and slaughterhouses. The five most common clinical signs were fever (92.3%), myalgia (46.1%), neck stiffness (25.6%), headache (23.1%), and nausea/vomiting (20.5%). S. suis was confirmed in two CSF and one blood specimens. All inpatients recovered following intravenous treatment with ceftriaxone every 12 h for 14 days and dexamethasone every 6 h for 4 days, while the outpatients were treated with 500 mg of amoxicillin three times daily for 7 days. The veterinary and environmental investigation identified the source of the pork for the festival, confirmed the presence of S. suis in the slaughtered pigs, and elucidated the sanitary measures applied at the pig farms and slaughterhouses. We conclude that infections of S. suis in humans can spread in cluster phenomena following the sharing of high-risk food. A prompt and early response, as well as early treatment of patients, is paramount in case finding to enable a favourable outcome of full recovery. Additionally, the implementation of the “One Health” approach provides a comprehensive picture of the management of S. suis infection in humans.

Identification of a Novel Linear B Cell Epitope on the Sao Protein of Streptococcus suis Serotype 2

Surface antigen one (Sao) protein is a bacterial surface protein identified in the important zoonotic pathogen Streptococcus suis serotype 2 (S. suis 2) during an extensive search for functional proteins. The Sao protein is anchored to the bacterial cell wall by the LPVTG motif and is widely distributed in many S. suis serotypes. In this paper, we present the immunodominant epitope peptide of the Sao protein that is recognized by BALB/c antibodies against the Sao protein: 355SEKQMPSVVNENAVTPEKQMTNKENDNIET384 (location Sao355−384). To determine the core epitope recognized by antibodies, we prepared truncation peptide libraries. Analyses of the immunoreactivity of truncation peptides with anti-Sao355−384 serum revealed that the most immunoreactive sequence was 355SEKQMPSVVNENAVTPEK372 (location Sao355−372). Moreover, we observed that this core epitope also showed good specificity based on the ratio of reactivity with serum from S. suis–positive patients compared to serum from S. suis–negative patients. Our results point to the potential of using the Sao355−372 peptide in diagnostic assays to determine S. suis infection in humans.

Fatal case of bacteremia caused by Streptococcus suis in a splenectomized man and a review of the European literature

Streptococcus suis is an emerging zoonotic human pathogen, which is a causative agent of invasive infections in people who are in close contact with infected pigs or contaminated pork products. It is associated with severe systemic infections, most commonly meningitis and sepsis, which may lead to high rates of morbidity and mortality. Serotype 2 is the most prevalent type in S. suis infections in humans. We have reported a case of a very rapidly proceeding fatal human S. suis infection in a splenectomized, but otherwise immunocompetent patient in Hungary. We would like to highlight the attention for this pathogen for the risk group patients, not only pig breeders, veterinarians, abattoir workers, meat processing and transport workers, butchers and cooks, that those persons who are immunocompromised including those with spleen removed, persons with diabetes mellitus, cancer and alcoholism, are also at greater risk of infection.

Genotypic diversity of Streptococcus suis strains isolated from humans in Thailand.

The purpose of this study is to characterize Streptococcus suis isolates recovered from human infections regarding serotype distribution, genotypic profile, clinical manifestations, and epidemiology. A total of 668 S. suis isolates recovered from human infections in Thailand were characterized based on serotyping by multiplex PCR and co-agglutination, genotypic profiles by multilocus sequence typing, and PCR for virulence-associated genes, as well as review of medical records. Serotype 2 (94.6%) was predominant, followed by serotype 14 (4.5%), 24 (0.45%), 5 (0.3%), and 4 (0.15%). Multilocus sequence typing analyses revealed seven clonal complexes (CC): CC1 (56.43%), CC104 (31.74%), CC233/379 (5.4%), CC25 (4.5%), CC28 (0.9%), CC221/234 (0.6%), CC94 (0.15%), and two singletons. The CC1 group contained serotype 2 and 14 isolates, while CC25, 28, 104, and 233/379 consisted of serotype 2 isolates only. CC221/234 contained serotype 5 and 24 isolates, whereas the single serotype 4 isolate belonged to CC94. Two singletons contained serotype 5 (ST235) and 2 (ST236) isolates. Our data showed that ST1 isolates were more associated with meningitis than those of other STs (p < 0.001). The major route of infection was shown to be close contact with infected pigs or contaminated raw pork-derived products, including occupational exposure and recent consumption of raw pork products. This study revealed a relatively large number of CCs of S. suis causing human infection in Thailand. Among them, CC1 followed by CC104, with serotype 2 isolates, are predominant. Food safety campaigns and public health interventions would be important for controlling the S. suis infection in humans.

Impact of a Food Safety Campaign on Streptococcus suis Infection in Humans in Thailand.

AbstractStreptococcus suis is an important zoonotic pathogen in swine and humans that causes sepsis and meningitis. Our previous study in Thailand showed that the prevalence of S. suis infection in humans, especially in northern areas of Thailand, and the transmission of the pathogen occurred mainly through the consumption of traditional raw pork products. Considering the high incidence proportion and mortality rate of the disease as an important public health problem, we implemented a food safety campaign in the Phayao Province in northern Thailand in 2011. We evaluated the effects of a food safety campaign by comparing the sociodemographic, clinical, and bacteriological characteristics of cases before and after the campaign. The follow-up study showed a marked decrease of the incidence proportion in the first 2 years, indicating the effectiveness of the campaign. In the third year, however, the incidence proportion slightly increased again, indicating the existence of deep-rooted cultural behaviors and the necessity of continuous public health intervention. Furthermore, epidemiological analysis of the cases made it possible to estimate the infectivity of the pathogen via the oral route of infection. In the present study, we showed the effectiveness of the food safety campaign for controlling the S. suis infection, and we present a role model public health intervention for prevalent areas affected by S. suis infection in humans.

Temporal and spatial association of Streptococcus suis infection in humans and porcine reproductive and respiratory syndrome outbreaks in pigs in northern Vietnam.

Porcine reproductive and respiratory syndrome (PRRS) outbreaks in pigs are associated with increased susceptibility of pigs to secondary bacterial infections, including Streptococcus suis - an important zoonotic pathogen causing bacterial meningitis in humans. This case-control study examined the association between human S. suis infection and PRRS outbreaks in pigs in northern Vietnam. We included 90 S. suis case-patients and 183 non-S. suis sepsis controls from a referral hospital in Hanoi in 2010, a period of major PRRS epizootics in Vietnam. PRRS exposure was determined using data from the National Centre of Veterinary Diagnosis. By univariate analysis, significantly more S. suis patients were reported residing in or adjacent to a PRRS district compared to controls [odds ratio (OR) 2·82, 95% confidence interval (CI) 1·35-5·89 and OR 3·15, 95% CI 1·62-6·15, respectively]. Only residency in adjacent districts remained significantly associated with risk of S. suis infection after adjusting for sex, occupation, and eating practices. SaTScan analysis showed a possible cluster of S. suis infection in humans around PRRS confirmed locations during the March-August period. The findings indicate an epidemiological association between PRRS in pigs and S. suis infections in humans. Effective strategies to strengthen control of PRRS in pigs may help reduce transmission of S. suis infection to humans.

Complex epidemiology and zoonotic potential for Cryptosporidium suis in rural Madagascar

Cryptosporidium spp. is the most important parasitic diarrheal agent in the world, is among the top four causes of moderate-to-severe diarrheal disease in young children in developing nations, and is problematic as an opportunistic co-infection with HIV. In addition, Cryptosporidium is a persistent challenge for livestock production. Despite its zoonotic potential, few studies have examined the ecology and epidemiology of this pathogen in rural systems characterized by high rates of overlap among humans, domesticated animals, and wildlife. To improve our understanding of the zoonotic potential of Cryptosporidium species in the rural tropics, we screened humans, livestock, peridomestic rodents, and wildlife using PCR-RFLP and sequencing-based approaches to distinguish species of Cryptosporidium in rural southeastern Madagascar. Cryptosporidium of multiple species/genotypes were apparent in this study system. Interestingly, C. suis was the dominant species of Cryptosporidium in the region, infecting humans (n=1), cattle (n=18), pigs (n=3), and rodents (n=1). The broad species range of C. suis and the lack of common cattle Cryptosporidium species (Cryptosporidium parvum and Cryptosporidium andersoni) in this system are unique. This report represents the fifth confirmed case of C. suis infection in humans, and the first case in Africa. Few rural human and livestock populations have been screened for Cryptosporidium using genus-specific genotyping methods. Consequently, C. suis may be more widespread in human and cattle populations than previously believed.

A human case of Streptococcus suis infection caused by an unencapsulated strain

Introduction: Streptococcus suis, an emerging zoonotic pathogen, causes invasive infections in persons who are in close contact with infected pigs or contaminated pork‐derived products. Although serotype 2 is the most prevalent type in S. suis infections in humans, to the best of our knowledge no human case caused by an unencapsulated strain has been reported previously. Case presentation: A 53‐year‐old male alcohol misuser with liver cirrhosis was admitted with sepsis to a hospital in Sukhothai Province, Thailand. He had consumed a homemade raw pork product 3 days prior to the onset of illness. An isolate from blood culture was confirmed as S. suis by species‐specific PCR and 16S rRNA gene sequencing, and as untypeable by a coagglutination test. The absence of a capsule around the bacterial cells was also confirmed by transmission electron microscopy. The isolate was also confirmed as sequence type 28 by sequence typing, and analysis of the capsule locus detected disruption of the cpsE–cpsK region, which comprises an approximately 2.5 kb fragment that contains phosphatase and kinase genes. Conclusion: We have identified the first human S. suis infection caused by an unencapsulated strain in a patient with liver cirrhosis. This unencapsulated strain was attributable to a mutation of the cps gene. Clinicians should be aware of the emergence of S. suis infection caused by unencapsulated strains, especially in patients with liver cirrhosis.

Survival of Helicobacter suis bacteria in retail pig meat

Helicobacter (H.) suis colonizes the gastric mucosa of pigs world-wide and is the most prevalent non-Helicobacter pylori Helicobacter species in humans. This agent might be transmitted to humans by manipulation or consumption of contaminated pork. H. suis is a very fastidious micro-organism and is extremely difficult to isolate. Therefore, we developed a non-culture dependent, quantitative detection method allowing differentiation of viable from dead H. suis bacteria in pork. This was established by a combination of ethidium bromide monoazide (EMA) treatment and real-time (RT)-PCR. This EMA RT-PCR was applied to 50 retail pork samples. In two samples, viable H. suis bacteria were detected. Sequence analysis of the obtained PCR products confirmed the presence of H. suis DNA. Viable H. suis bacteria persisted for at least 48h in experimentally contaminated pork. In conclusion, consumption of contaminated pork may constitute a new route of transmission for H. suis infections in humans.

Streptococcus suisMeningitis in Swine Worker, Minnesota, USA

To the Editor: Streptococcus suis is a major bacterial pathogen in swine worldwide. Historically, cases in humans have occurred sporadically, mostly in Asia (1,2). However, an outbreak in China involved 215 human cases and 39 deaths (3). Only 3 human cases of S. suis disease were documented in the United States before 2011: 2 domestically acquired cases in New York and Hawaii, and 1 case in a person in California who was probably exposed in the Philippines (4). We describe a case of S. suis disease in a swine worker in Minnesota, USA. The case-patient was a previously healthy 60-year-old man (truck driver). On December 14, 2011, severe headache and chills developed, which he attributed to the onset of influenza. He had a history of migraine headaches, and used prescription medications to treat his headache. However, on December 15, he awoke with a severe headache that was unresponsive to treatment. Despite having to stop his truck several times because of the severe headache, he successfully completed his delivery route. Early on December 16, his wife drove him to a nearby emergency department after he did not respond to ordinary commands. The patient had reduced coordination and behaved aggressively. His blood pressure was 92/52 mm Hg. He underwent intubation for 24 hours for airway protection, and a lumbar puncture was performed. Cerebrospinal fluid (CSF) had a leukocyte count of 10,501 cells/μL (99% neutrophils), a protein level of 509 mg/dL, and a glucose level of 38 mg/dL. A few gram-positive diplococci were observed in CSF. Complete blood count showed a leukocyte count of 14,800 cells/μL (92% neutrophils), a hemoglobin level of 14.1 g/dL, and a platelet count of 157,000/μL. Streptococcus suis was isolated from CSF and 2 of 4 blood cultures. Identification of S. suis was confirmed by using 16S rRNA gene sequencing at the Minnesota Department of Health. The patient was given decadron, ceftriaxone, ampicillin, vancomycin, and acyclovir. During hospitalization, antimicrobial drugs were tapered until he received only ceftriaxone. Major symptoms were severe headache and nausea. He was discharged in good condition on day 10 of hospitalization and then completed a 14-day course of ceftriaxone. There are 35 known serotypes of S. suis (1). Of these serotypes, serotype 2 is most commonly identified in infected swine and humans (2). The S. suis isolate from this patient was identified as serotype 2 by coagglutination test at the International Reference Laboratory at the Universite de Montreal (5). The sequence type was identified by PCR as type 25, a common type in North America (6,7). The isolate was positive by PCR for the gene encoding virulence-associated factor muraminidase-released protein and negative for genes encoding virulence-associated extracellular factor and suilysin (8). The isolate was genotyped by enterobacterial repetitive intergenic consensus PCR and compared with 750 swine isolates in the University of Minnesota Veterinary Diagnostic Laboratory database (9). The obtained fingerprint matched that of 15 S. suis isolates from swine meningitis cases in Minnesota and Indiana during 2006–2010. The patient worked for a trucking company that transports swine throughout the Midwest. His daily work required traveling to swine farms in Minnesota and making occasional trips to South Dakota and Iowa. His job was to load slaughter-weight swine into the truck and deliver them to regional slaughterhouses. Approximately 1 month before illness onset, he reported moving swine from a farm on which the farmer reported pneumonia, a rare yet reported manifestation of S. suis infection in swine. The patient reported always wearing coveralls, boots, and gloves while loading and unloading swine, but he wore a dust mask only occasionally. He had no recent foreign travel and no skin breaks. However, absence of open wounds has been noted in previous case-patients (10). The reported incubation period for S. suis infection in humans ranges from hours to weeks, and open wounds are associated with shorter incubation periods (2). Case-patients in the United States reported known risk factors, including handling ill swine or slaughtering and processing swine for meat (4). In this instance, the patient only loaded and unloaded slaughter-weight swine from his truck. He reported transporting swine that had pneumonia, which is common in finishing stages of swine production. However, although S. suis can cause pneumonia, this disease in finishing swine is probably caused by other common pathogens such as Pasteurella multocida, Mycoplasma hyopneumoniae, influenza virus, and porcine reproductive and respiratory syndrome virus. A definitive source of infection for this patient was not identified. This case demonstrates a rare but potentially under-recognized occupational hazard for workers in the swine industry in the United States.

Zoonosis Due to &amp;lt;i&amp;gt;Bruella suis&amp;lt;/i&amp;gt; with Special Reference to Infection in Dogs (Carnivores): A Brief Review

Brucella suis (B. suis) is the major cause of porcine brucellosis. Zoonosis due to B. suis infection associated with transmission by various animal species is reported. Recently an increase in brucellosis associated with feral swine transmitted B. suis infection in humans and hunting dogs is emerging. Reports on B. suis infection in carnivores including dogs is scant. This report gives a brief review of B. suis zoonosis with particular reference to B. suis infection in dogs (carnivores).

Population-Based Study of Streptococcus suis Infection in Humans in Phayao Province in Northern Thailand

Background Streptococcus suis infection in humans has received increasing worldwide recognition.Methods and FindingsA prospective study of S. suis infection in humans was conducted in Phayao Province in northern Thailand to determine the incidence and the risk behaviors of the disease in this region in 2010. Thirty-one cases were confirmed. The case fatality rate was 16.1%, and the estimated incidence rate was 6.2 per 100,000 in the general population. The peak incidence occurred in May. The median age of the patients was 53 years and 64.5% were men. Consumption of raw pork products was confirmed in 22 cases and the median incubation period (range) was 2 days (0–11) after consumption of raw pork products. Isolates from 31 patients were confirmed as serotype 2 in 23 patients (74.2%) and serotype 14 in eight patients (25.8%). The major sequence types (STs) were ST1 (n = 20) for serotype 2 and ST105 (n = 8) for serotype 14. The epidemiological analysis suggested three possible clusters, which included 17 cases. In the largest possible cluster of 10 cases in Chiang Kham and its neighboring districts in May, the source of infection in four cases was identified as a raw pork dish served at the same restaurant in this district. Microbiological analysis confirmed that three of four cases associated with consumption of raw pork at this restaurant were attributable to an identical strain of serotype 2 with ST1 and pulsotype A2.ConclusionsOur data suggest a high incidence rate of S. suis infection in the general population in Phayao Province in 2010 and confirm a cluster of three cases in 31 human cases. Food safety control should be strengthened especially for raw pork products in northern Thailand.

Prevalence of &lt;i&gt;Streptococcus suis&lt;/i&gt; Genotypes in Isolates from Porcine Endocarditis in East Japan

Streptococcus suis is an important pathogen for both swine and humans. In this study, we genotyped 105 S. suis isolates from porcine endocarditis in East Japan on the basis of profiles of capsular serotype-specific, virulence-associated and pilus-associated genes. The most common genotype was cps2J/mrp+/epf-/sly-/sbp2-/sep1-/sgp1+ (76.19%), followed by nt(non-typeable)/mrp+/epf-/sly-/sbp2-/sep1-/sgp1+ (7.62%) and cps2J/mrp+/epf+/sly+/sbp2+/sep1-/sgp1- (7.62%). The representative isolates of mrp+/epf-/sly-/sbp2-/sep1-/sgp1+ were classified into ST28 complex, a clonal complex previously referred to as ST27 complex, whereas those of mrp+/epf+/sly+/sbp2+/sep1-/sgp1- were classified into ST1 complex by multilocus sequence typing. Because the majority of human clinical isolates were assigned to ST1 and ST28 complexes, most isolates from porcine endocarditis investigated in this study may have the potential to cause S. suis infection in humans.

Isolation and Characterization of 89K Pathogenicity Island-Positive ST-7 Strains ofStreptococcus suisSerotype 2 from Healthy Pigs, Northeast China

Streptococcus suis is a swine pathogen which can also cause severe infection, such as meningitis, and streptococcal-like toxic shock syndrome (STSS), in humans. In China, most of the S. suis infections in humans were reported in the southern areas with warm and humid climates, but little attention had been paid to the northern areas. Data presented here showed that the virulent serotypes 1, 2, 7, and 9 of S. suis could be steadily isolated from the healthy pigs in the pig farms in all the three provinces of Northeast China. Notably, a majority of the serotype 2 isolates belonged to the 89K pathogenicity island-positive ST-7 clone that had historically caused the human STSS outbreaks in the Sichuan and Jiangsu provinces of China, although the human STSS case caused by S. suis had never been reported in northern areas of China. Data presented here indicated that the survey of S. suis should be expanded to or reinforced in the northern areas of China.