Haemolysin-deficient variants of Streptococcus pyogenes and S. dysgalactiae subsp. equisimilis may be overlooked as aetiological agents of pharyngitis

Dierksen, Karen P.; Tagg, John

doi:10.1099/0022-1317-49-9-811

Cited by 20 publications

(18 citation statements)

References 12 publications

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“…equisimilis rappresenta un agente eziologico infrequente di faringotonsillite sporadica, nell'adulto e nel bambino. Nonostante tale microrganismo formi generalmente tipiche large colonies beta-emolitiche, sono noti stipiti deficitari dell'enzima emolisina, formanti colonie gamma-emolitiche (non-emolitiche), come descritto anche per S. pyogenes (4). Dunque, è in primo luogo fondamentale evitare l'errore di considerare a priori le eventuali colonie non-emolitiche quali isolati appartenenti alla flora commensale orofaringea.…”

Section: Conclusioni E Discussioneunclassified

“…L'esecuzione del test di agglutinazione al lattice con antisieri dei gruppi A, B, C, D, F e G (Streptococcal grouping kit, Oxoid) ha consentito di attribuire l'isolato al gruppo C di Lancefield. Le colonie alfa-emolitiche isolate sono state identificate biochimicamente come Streptococcus oralis e Streptococcus mitis (Vitek 2 automatic system for biochemical identification of bacteria and yeasts, bioMérieux) e ciò al fine di escludere che la presenza di Streptococcus salivarius potesse inibire la crescita di streptococchi beta-emolitici, all'interno del raggio di azione delle batteriocine rilasciate da S. salivarius nel terreno di coltura (4).…”

Section: Materiali E Metodiunclassified

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Streptococcus dysgalactiae subsp. equisimilis: two cases of tonsillitis

Savini¹,

Giuseppe²,

Manna³

et al. 2008

Microbiol Med

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INTRODUZIONES. dysgalactiae subsp. equisimilis appartiene al gruppo C o G di Lancefield ed è responsabile di rare epidemie di faringotonsillite nelle popolazioni adulta e pediatrica (1); è invece considerato un agente eziologico inusuale di episodi tonsillitici acuti a carattere sporadico (2). Sono documentati tra l'altro episodi di setticemia, endocardite, polmonite, meningite, sostenuti da S. dysgalactiae subsp. equisimilis, che non è pertanto agente eziologico di sole infezioni dell'alto tratto respiratorio (1, 2). Le infezioni faringotonsillari da streptococchi dei gruppi C e G di Lancefield sono talora responsabili di incremento del titolo antistreptolisinico e dello sviluppo di sequele non suppurative, in particolare glomerulonefrite ed artrite reattiva (6, 7), similmente a quanto ormai noto a proposito delle infezioni da S. pyogenes. Diversamente, gli streptococchi del gruppo B non sono mai stati associati a complicanze non suppurative; tuttavia sono descritte, in corso di infezioni faringotonsillari da S. agalactiae, beta-emolitico del gruppo B, localizzazioni silenti o sintomatiche del medesimo stipite a livello cutaneo o genitourinario (2). Come descritto da altri autori riguardo alle infezioni da S. pyogenes, noi riteniamo che una eradicazione faringotonsillare subtotale di S. dysgalactiae subsp. equisimilis possa determinare l'insorgenza di recidive e/o di persistente colonizzazione tonsillare e faringea, condizione, quest'ultima, sfavorevole per la comunità, oltre che il paziente stesso. TassonomiaSu terreni al sangue, gli streptococchi beta-emolitici formano tipiche small colonies (Streptococcus anginosus group) o large colonies (Streptococcus pyogenes, gruppo A; Streptococcus equi subsp. zooepidemicus, group C; Streptococcus dysgalactiae subsp. equisimilis, gruppo C o G). Per quanto S. pyogenes e S. dysgalactiae siano solitamente considerati streptococchi beta-emolitici, è nota l'esistenza di varianti non-emolitiche (4). Stipiti non-emolitici di S. pyogenes sono stati isolati sia da tonsille di portatori sani quanto da casi di faringotonsillite acuta. In particolare, è stata descritta un'epidemia di faringotonsillite SUMMARYWe described two case reports of S. dysgalactiae subsp. equisimilis tonsillitis occurred from January 2005 to January 2007, among patients who come to our observation during these two years. These patients are paradigmatic of some conditions: adult age, absence of underlying diseases, outbreak of similar pharyngo-tonsillar sympyomatology, unsuccessful oral penicillin therapy, isolation of S. dysgalactiae subsp. equisimilis from throat swab, complete recovery after oral beta-lattamic antibiotic therapy, but total clearance of the microorganism only after oral macrolides administrations. Thus, the intracellular localization of S. dysgalactiae subsp. equismilis, could be in charge of the failure of beta-lattamic antibiotics therapy.

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Section: Conclusioni E Discussioneunclassified

Section: Materiali E Metodiunclassified

Streptococcus dysgalactiae subsp. equisimilis: two cases of tonsillitis

Savini¹,

Giuseppe²,

Manna³

et al. 2008

Microbiol Med

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“…However, some strains are found to induce α-hemolysis or no hemolysis at all, in the abovedescribed standard conditions [20][21][22]. As in the case of S. pyogenes, there exist strains of SDSE which produce oxygen-labile streptolysin O, and no streptolysin S [20,23,24]. The occurrence of such strains has been an incentive to search for media and conditions of incubation which would enhance the activity of streptolysin O [20].…”

Section: Introductionmentioning

confidence: 99%

“…As in the case of S. pyogenes, there exist strains of SDSE which produce oxygen-labile streptolysin O, and no streptolysin S [20,23,24]. The occurrence of such strains has been an incentive to search for media and conditions of incubation which would enhance the activity of streptolysin O [20]. Some authors suggest parallel incubation of three plates aerobically, anaerobically and in 5% CO 2 atmosphere [25].…”

Section: Introductionmentioning

confidence: 99%

“…Some authors suggest parallel incubation of three plates aerobically, anaerobically and in 5% CO 2 atmosphere [25]. Similarly as with culture test for S. pyogenes [26], it is necessary to stab the inoculated agar with an inoculation loop in order to discover subsurface hemolysis [20]. Due to the occurrence of strains displaying changed hemolytic activity, neither α-hemolytic nor nonhemolytic streptococci should be treated as non-pathogenic, especially if they are isolated from patients showing clinical symptoms such as tonsillopharyngitis, rheumatic fever, erythema marginatum, reactive arthritis or glomerulonephritis [25].…”

Section: Introductionmentioning

confidence: 99%

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Soft tissue infection caused by Streptococcus dysgalactiae subsp. equisimilis possessing group Aantigen: a and review of the literature

Karyński¹,

Letowska²,

Grzesiowski³

2012

pdia

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Streptococcus dysgalactiae subsp. equisimilis Isolated From Infections in Dogs and Humans: Are Current Subspecies Identification Criteria accurate?

2016

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Streptococcus dysgalactiae is a pyogenic species pathogenic both for humans and animals. Until recently, it has been considered an exclusive animal pathogen causing infections in wild as well as domestic animals. Currently, human infections are being reported with increasing frequency, and their clinical picture is often similar to the ones caused by Streptococcus pyogenes. Due to the fact that S. dysgalactiae is a heterogeneous species, it was divided into two subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD). The first differentiation criterion, described in 1996, was based on strain isolation source. Currently applied criteria, published in 1998, are based on hemolysis type and Lancefield group classification. In this study, we compared subspecies identification results for 36 strains isolated from clinical cases both in humans and animals. Species differentiation was based on two previously described criteria as well as MALDI-TOF and genetic analyses: RISA and 16S rRNA genes sequencing. Antimicrobial susceptibility profiles were also determined according to CLSI guidelines. The results presented in our study suggest that the subspecies differentiation criteria previously described in the above two literature positions seem to be inaccurate in analyzed group of strains, the hemolysis type on blood agar, and Lancefield classification should not be here longer considered as criteria in subspecies identification. The antimicrobial susceptibility tests indicate emerging of multiresistant human SDSE strains resistant also to vancomycin, linezolid and tigecycline, which might pose a substantial problem in treatment.

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Haemolysin-deficient variants of Streptococcus pyogenes and S. dysgalactiae subsp. equisimilis may be overlooked as aetiological agents of pharyngitis

Cited by 20 publications

References 12 publications

Streptococcus dysgalactiae subsp. equisimilis: two cases of tonsillitis

Streptococcus dysgalactiae subsp. equisimilis: two cases of tonsillitis

Soft tissue infection caused by Streptococcus dysgalactiae subsp. equisimilis possessing group Aantigen: a and review of the literature

Streptococcus dysgalactiae subsp. equisimilis Isolated From Infections in Dogs and Humans: Are Current Subspecies Identification Criteria accurate?

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