Group Milleri Streptococci in paediatric infections

Group Milleri Streptococci (GMS), a subgroup of viridans streptococci, are commensals of the human respiratory, gastrointestinal and urogenital tracts. GMS tend to cause purulent infections often resulting in abscess formation. Little is known about the significance of these organisms in children.

For this retrospective study, a collection of 636 GMS positive isolates from 475 patients was used to identify 39 (8.2 %) paediatric patients (age < 18 years) with GMS infections (46 isolates) during a four-year period.

There were 19 intra-abdominal, eleven dental/oropharyngeal, seven soft tissue and two central nervous system infections. Thirty-five patients (95 %) underwent primary surgical interventions. Furthermore, two patients - one with GMS meningitis that progressed to cerebral empyema and another with a liver abscess - initially treated with antibiotic agents alone eventually required surgical intervention to cure the infection. Only two children were treated with antibiotics alone. Polymicrobial infection was found in 22 (48 %) isolates; polymicrobial infection was most common in patients with intra-abdominal infection with 74 % and lowest in dental/oropharyngeal patients with 9 % (p = 0.001); Escherichia coli (n = 9) and Bacteroides fragilis (n = 9) were the most common secondary pathogens. Complications due to GMS infections were found in five cases (13 %). No patient died from GMS infection. Preferred antibiotics were penicillins (56 %) and cephalosporins (37 %). GMS tested susceptible to penicillin, cephalosporins, carbapenems in 100 % and clindamycin in 93 %.

GMS infections in paediatric patients usually require both antibiotic therapy and surgical drainage. These infections may become life-threatening if not diagnosed in a timely fashion and treated aggressively.