Streptococcus equi subspecies zooepidemicus: an emergent cause of meningoencephalitis in Northeastern Brazil.

This study describes an outbreak of Streptococcus equi subspecies zooepidemicus infections that caused meningoencephalitis and bacteremia related to unpasteurized milk consumption in northeastern Brazil. Epidemiological investigations and a brief literature review were conducted. Strains with possible neurotropism had not been identified in Brazil before these cases; however, in 2023, another case of meningoencephalitis caused by Streptococcus equi sp. zooepidemicus was described, revealing the need to maintain surveillance and highlighting that these neurotropic strains continue to circulate in the environment.

Streptococcus equi subsp. zooepidemicus: High molecular diversity of Argentinian strains isolated from mares with endometritis.

Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is a mucosal commensal of the lower genital tract in horses and is the most isolated bacterium causing endometritis in mares. The aim of this study was to determine the molecular diversity of S. zooepidemicus obtained from endometritis in mares in Buenos Aires province, Argentina. Thirty isolates obtained from the uterus of mares in 2005 and 2017 were studied. The MLST scheme was applied to identify the Argentinian genotypes and the clonal relationships and patterns of evolutionary descent were identified using the eBURST algorithm - goeBURST. Twenty six different Sequence types (STs) were identified, being only 11 of them previously reported in horses and also, from several host species and tissues. The other 15 STs were reported in Argentinian reproductive strains of mares in our study for the first time. The genotypes obtained from uterus in Argentina were not evenly distributed when all the published S. zooepidemicus STs were analysed, thus, it was not possible to establish that the same lineage circulates in our equine population. The fact that the identified genotypes were also reported in other countries, diverse samples and host species suggest that there is not a host, and an anatomical niche adaptation. Finally, the isolation of the same genotype in the vagina/clitoris and the uterus of the same mare highlights the versatility of S. zooepidemicus and its role as an opportunistic pathogen.

Outbreak of Glomerulonephritis Caused by Streptococcus zooepidemicus SzPHV5 Type in Monte Santo de Minas, Minas Gerais, Brazil.

Streptococcus zooepidemicus is an emerging and opportunistic zoonotic pathogen which plays an important role in the development of severe and life-threatening diseases and is potentially capable of triggering large glomerulonephritis outbreaks. Between December 2012 and February 2013, 175 cases of glomerulonephritis were confirmed in the town of Monte Santo de Minas, MG, Brazil. During the outbreak, 19 isolates of S. zooepidemicus were recovered, 1 from ice cream, 2 from the oropharynx of food handlers, and 16 from patients affected by acute poststreptococcal glomerulonephritis (APSGN). All S. zooepidemicus isolates involved in the outbreak amplified the same sequence of the hypervariable region of the SzP protein (SzPHV5) and presented indistinguishable banding patterns with high similarity (>99%) to each other by the repetitive element sequence-based PCR (rep-PCR) technique. Inspection programs on the milk supply chain should be strengthened and continuously encouraged so that the health of consumers is preserved.

Phenotypical assays and partial sequencing of the hsp60 gene for identification of Streptococcus equi.

Strangles is an acute and contagious disease characterized by inflammation of the upper respiratory tract of horses. The etiological agent of strangles is the bacteria S. equi subsp. equi, which belongs to the Lancefield group C. Opportunistic agents from the same group are frequently isolated from horses with strangles and may induce mistaken diagnoses. Among the subspecies of S. equi, the phenotypic features are almost undistinguishable; however, the pathogenic potential is widely differentiated. The aim of this study was to characterize S. equi isolates obtained from clinical samples of strangles by phenotypic tests and to analyze the partial sequences obtained from fragments of the hsp60 gene. In this work, 26 strains of Streptococcus spp. isolated from horse clinical samples were analyzed. By phenotypical assays, 18 were characterized as S. equi subsp. equi, five as S. equi subsp. zooepidemicus, two as S. dysgalactiae subsp. equisimilis, and one as Streptococcus sp. However 21 isolates were identified as S. equi subsp. equi and five as S. equi subsp. zooepidemicus by DNA sequencing. The sequencing of the partial hsp60 gene was demonstrated to be an alternative method to analyze and differentiate strains of Streptococcus spp. In addition, this method can be useful as a discriminatory tool for characterization of atypical isolates.