On December 29, 2017, a 33-year-old pregnant woman, gravida 1, at 37 weeks of gestation, was admitted to the emergency department of Guangdong Women and Children Hospital (Guangzhou, China) because of fever lasting for 3 hours and fetal movement increased. No abnormality was found in her regular antenatal examination. However, a week before admission, the patient had started to experience fatigue and throat discomfort.
On admission, the physical findings were within normal levels, except for a febrile condition (temperature: 39.5°C). However, during the following 2 hours, an emergency cesarean section (CS) was performed due to fetal distress. The operation went well and the neonate was transferred to the neonatal intensive critical care unit (NICU) empirically treated with penicillin and cephalosporin for the fever. The blood culture for the infant was negative. The clinic findings demonstrated that the infant became in good health later.
Following the cesarean section, the vital signs of the patient were within normal range at first except for the poor uterine contraction with the pressing to bleed 300 ml. Then, balloon tamponade, uterine artery embolization and abdominal subtotal hysterectomy were successively performed to control the ongoing uterine bleeding. Transfusion of red cell suspension liquid, fresh frozen plasma (FFP), cryoprecipitate and apheresis platelet which were totally up to about 13,400 ml were also initiated. The drastic deterioration of her clinical findings was shown in the Fig. 2. Although the patient was received aggressive modern management with antibiotics and supportive therapy, in an attempt to correct blood clotting, promote contractions, fluid replacement, maintain water and electrolyte balance, etc., the condition deteriorated rapidly including hypotension, progressive decrease in blood oxygen saturation, systemic edema, and metabolic acidosis and the pregnant woman was finally died of disseminated intravascular coagulation and septic shock within 24h after admission.
The pathogenic analysis demonstrated two sets of blood culture collected on admission and after the cesarean section respectively were both present positive and Gram-positive coccus were both observed under light microscopy. After sub-culturing on 5% sheep blood agar plate under 5% CO2 atmosphere for 24h, the isolate was identified as Streptococcus pyogenes using a Microflex matrix-assisted laser desorption/ionization time-of-flight mass spectrometry device (Bruker). Further, pairwise comparison of the 16S rRNA gene sequences was performed using BLAST searches (https://blast.ncbi.nlm.nih.gov/Blast.cgi) and showed that the isolate designed as SFY-1 shared highest similarities to Streptococcus pyogenes JCM 5674T (99.5 %) but less than 97.7 % with other members of the genus Streptococcus. To determination its epidemiological characteristics, template preparation, PCR and sequence analysis were performed according to the protocols described in the CDC website (https://www2a.cdc.gov/ncidod/biotech/strepblast.asp) [10]. M protein gene sequence for the strain SFY-1 was detected as M1T1 genotype, which associated with toxic disease. The GenBank accession numbers for 16S rRNA gene sequence and M protein gene sequence of the strain SFY-1 was MW425601 and MW699016, respectively.
In parallel, airway secretion culture was positive with colonies identified as the same as that of blood culture. Of note, vaginal and pharynx cultures were negative. Besides, antibiotic susceptibility tests for the strain SFY-1 showed susceptibility to chloramphenicol, vancomycin, trimethoprim/sulfamethoxazole, cefotaxime, benzylpenicillin, cefotaxime, amoxicillin, levofloxacin, linezolid, moxifloxacin, quinupristin/dalfopristin and rifampicin but resistance to erythromycin, clindamycin, tetracycline and telithromycin. Moreover, the IgM antibody tests for Influenza A virus was positive.
According to the clinical characteristics and microbiological results, the pregnant woman was finally diagnosed with GAS-TSS. The whole striking changing course of GAS-TSS and diagnosis in pregnant woman are shown in Fig. 1.