Intra-abdominal abscesses secondary to <i>Streptococcus anginosus</i> infection in a postpartum patient: A case report and review of the literature

doi:10.4236/ojog.2012.23048

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Open Journal of Obstetrics and Gynecology, 2012, 2, 235-238 OJOG

http://dx.doi.org/10.4236/ojog.2012.23048 Published Online September 2012 (http://www.SciRP.org/journal/ojog/)

Intra-abdominal abscesses secondary to Streptococcus

anginosus infection in a postpartum patient: A case

report and review of the literature

Rehab Shabana1, Lindsay Berbiglia2, John Barnwell3, Ronald Cheek1, Mark Wolf4,

Bernard Gonik1

1Department of Ob s tetrics and Gynecology, Wayne State University School of Medicine/Detroit Medical Center, Detroit, USA

2Department of General Surgery, Detroit Medical Center, Detroit, USA

3Department of General Surgery, Wayne State University School of Medicine/Detroit Medical Center, Detroit, USA

4Department of Internal Medicine, Detroit Med ical Cent er, Detroit, USA

Email: [email protected]

Received 24 March 2012; revised 30 April 2012; accepted 11 May 2012

ABSTRACT

Although rare, infection with Streptococcus angino-

sus has a known predilection for abscess formation.

We report here a case of a 20 year-old, otherwise

healthy female patient noted to have developed ab-

dominal and pelvic abscesses secondary to Strepto-

coccus anginosus infection. Although the inciting fo-

cus of the pathogen remains unclear in our patient,

this case report emphasizes the importance of rapid

identification of the organism and highlights the ap-

proach to therapeutic options in the management of

such cases.

Keywords: Streptoc occu s anginosus; Abdominal

Abscess

1. CASE

A 20 year-old G4 P3-0-1-3 presented to the emergency

department seven days after spontaneous vaginal deli-

very of a term infant, complaining of worsening lower

abdominal pain since hospital discharge. Aside from a

first degree perineal laceration, which was repaired un-

eventfully, the entire prenatal course and delivery were

otherwise uncomplicated. She denied fever, nausea, vo-

miting or change in bowel function. Vital signs were

stable except for a resting tachycardia of 118 bpm. Tem-

perature was 36.3˚C. Pertinent physical exam findings

included a distended abdomen which was soft, mildly

tender in all quadrants, with bowel sounds present, and

without rebound or guarding. A small non-tender, re-

ducible umbilical hernia was also appreciated on exam.

The uterus was well involuted below the umbilicus and

non-tender. Pelvic exam revealed small, non-foul smell-

ing lochia and no cervical motion or adnexal tenderness.

There was bulging noted in the posterior vaginal fornix.

The perineal repair was healing well, without induration

or erythema. Laboratory studies included a white blood

cell count of 21,000 cells per liter and a hemoglobin of

10.5 grams. The urinalysis was unremarkable, and sub-

sequent urine and blood cultures were negative. She was

HIV negative by antibody testing.

The patient underwent ultrasonography which re-

vealed a normal appearing postpartum uterus and adnexa.

A large amount of free fluid was seen in the abdomen

and pelvis. The appendix was not visualized. The CT

scan demonstrated multiple areas of loculated fluid

pockets (Figure 1). Again, the appendix was unable to

be visualized. The patient was empirically started on

cefoxitin in the emergency department. She was then

continued on metronidazole and ampicillin therapy upon

Figure 1. Admission computed tomography scan de-

monstrating multiple fluid collections in the peritoneal

cavity as denoted by asterisks.

OPEN ACCESS

R. Shabana et al. / Open Journal of Obstetrics and Gynecology 2 (2012) 235-238

236

admission, and switched to Ampicillin-Sulbactam on the

fifth day of admission. A culdocentesis was performed

with drainage of 420 cc of purulent, foul-smelling fluid.

Cultures yielded Streptococcus anginosus and Prevotella

species. After surgery and interventional radiology con-

sultations, three indwelling 10-French pigtail catheters

were placed transabdominally at sites thought to contain

the largest fluid collections by CT imaging . Over 200 cc

of purulent fluid were initially collected at each of these

drainage sites, with steadily diminishing amounts subse-

quently. Aerobic and anaerobic cultures were negative

from all of these aspirates. At the drainage sites, abscess

resolution was noted later in the hospital course, while

other collections were re-demonstrated on CT imaging

(Figure 2). Throughout this time, the patient remained

stable, with improving symptomatology. Occasional low

grade temperature elevations were noted, without a newly

identified source. On hospital day 15, the previously

noted umbilical hernia became tender to palpation with

spontaneous drainage of purulent material similar to that

noted above. An associated fluid collection measuring

2.6 cm × 3.4 cm was identified. Cultures were again

negative. The patient was taken to the operating room

fordrainage of this collection an d umbilical h ernia repair.

The collection was drained, copiously irrigated with nor-

mal saline solution, and the fascial umbilical defect was

repaired with the skin left open. On hospital day 20, the

patient continued to be afebrile, was tolerating diet and

showed resolution of her abdominal pain. She was dis-

charged home on broad spectrum oral antibiotic therapy

with drains remaining in place. One week later, at her

Figure 2. Hospital day 13 computed tomography

scan after placement of drainage catheters. Reso-

lution of right and left lower quadrant collections

visualized. A discrete fluid collection within the

mesenteric space is noted (*).

scheduled follow up office visit, the patient had no

complaints and drains were removed.

2. DISCUSSION

Streptococcus anginosus group, also known as S. milleri,

are a gram positive cocci with known commensal colo-

nization of the mouth, nasopharynx, gastrointestinal tract,

and lower genital tract, with isolation rates ranging from

15% - 30% [1,2 ]. This group consists of three species: S.

anginosus, S. constellatus, and S. intermedius, and se-

veral subspecies [3]. Though all members of the Strep-

tococcus anginosus group share common phenotypic

characteristics, confusion surrounding serologic and he-

molytic characterization persists. Currently proposed me-

thods for identification of the Streptococcus anginosus

group, to the species level in particular, are time con-

suming and not routinely done in clinical practice. This

has lead to incomplete or misidentification of this gro up,

often as S. viridans organisms, which have different pre-

dilection and resistance patterns [4]. This is of significant

concern, in that the lack of recognition can lead to mis-

management of patients with life-threatening conditions.

The unique characteristic of the S. anginosus group,

distinguishing it from other streptococci, is its role in

pyogenic infections and its strong association with ab-

scess formation. S. anginosus produces deep-seated ab-

scesses in a frequency double that of the remainder of the

S. viridians group [5]. Serious underlying disease, such

as immunodeficiency, malignancy, and diabetes, as well

as, recent surgical intervention are predisposing factors

in 33% - 76% of S. anginosus infections [1]. Trauma to

the mucosal barrier and intra-abdominal infections, in-

cluding appendicitis and cholecystitis, were noted incit-

ing foci, although abscess formation may occur without

an obvious source [5-7].

Few reports of S. anginosus group infections are iden-

tified in a healthy obstetric and gynecologic patient po-

pulation. Isolated cases of wound infection, pelvic ab-

scesses, labial abscesses, and tuboovarian abscesses have

been previously described [1,8]. Of interest, three cases

of epidural abscesses have been reported in obstetric

patients, of which one was at 20 weeks of gestation, oc-

curring as a spontane ous event with out catheterization or

other invasive procedures. This case is of particular in-

terest due to the patient’s lack of predisposing conditions

and quick clinical deterioration [9]. The other two cases

involved young healthy women after spontaneous vagi-

nal deliveries with epidural catheter placement for anal-

gesia. Both underwent laminectomy and treatment with

antibiotics [8]. Th ere have also been limited case reports

of neonatal sepsis involving this organism with the pre-

sumption of vertical transmission from a colonized mother

[10]. S. anginosus may also play a role in causing septic

R. Shabana et al. / Open Journal of Obstetrics and Gynecology 2 (2012) 235-238 237

abortions via ascending infection [11].

The case presented is of particular interest for several

reasons including the lack of obvious inciting cause, the

disparity between the patient’s eventually recognized

disease state and her presenting symptomatology, and the

choice of management. Treatment with systemic antibi-

otics and serial interventional radiology-directed drain-

age versus early surgical exploration remains controver-

sial. It has been noted in previous studies, that the ma-

jority of infectious S. anginosus cases originate from

skin/soft tissue or intraabdominal sources. Of 186 cases

of S. anginosus noted in a retrospective study, 64 had

skin/soft tissue manifestations and 41 had intraabdominal

manifestations. These in cluded liver abscess, cho langitis,

peritonitis, pancreatic abscess, subphrenic abscess, and

most commonly appendicitis, the source in 23 of the 41

cases [1]. Another study detailing 33 cases of S. angino-

sus and bacteremia found the majority were due to in-

traabdominal sources [7]. The inciting factors in these

cases included cholecystitis/cholangitis (18%) and ap-

pendicitis (12%) [7]. Given our patient’s extensive in-

traabdominal disease process, appendicitis was considered

a possible inciting focus. The patient underwent several

imaging procedures, including ultrasonography and se-

rial CT scanning, none of which allowed visualization of

the appendix. Though not visualized, there was also no

noted area of increased inflammation surrounding the

area of the appendix to suggest appendicitis. Of note, S.

anginosus is a commensal organism of the appendix and

was isolated from a quarter of normal-appearing appen-

dices, not in the setting of appendicitis [12]. Lastly, re-

garding a source of the infection, it should be recalled

that the patient had a small perineal laceration repaired in

an uncomplicated manner at the time of delivery. As pre-

viously noted, S. anginosus species are known to colo-

nize the lower female genital tract. Therefore, trauma to

this mucosal barrier may have been the site for entrance

of the pathogen. Our patient did not have any signs of in-

flammation, induration or purulence at the laceration site

upon subsequent presen tation to the hospital. Of interest,

certain S. anginosus biotypes have a specific affinity for

the vaginal mucosa. They are identified by the fact they

produce acid from raffinose and melibiose in the labora-

tory. Unfortunately our clinical specimen was not tested

with these substrates to help better define the source of

the organism.

A final point of interest in this case is the manage ment

of multiple intra-abdominal abscesses with percutaneous

drainage instead of surgical intervention. On presentatio n

the patient had significant abdominal tenderness, but

lacked other gastrointestinal symptoms. She was tolerat-

ing a regular diet and complained of only mildly de-

creased appetite. She was afebrile and hemodynamically

stable. Also, at the time of presentation, the patient had

been symptomatic for seven days, making surgical inter-

vention a potentially more complicated approach. Given

the noted clinical findings and the apparent amenability

of the fluid collections to drainage, the decision was

made to proceed wit h percutaneous drai na ge.

On review, there are several studies detailing the use

of radiology guided percutaneous drainage catheters for

intraabdominal abscesses and success rates comparable

to that of open intervention, with overall success rates

between 33% and 100% [13]. Three studies were re-

viewed detailing the management of intraabdominal ab-

scesses, leading to similar conclusions that percutaneous

drainage had a higher success rate determined by abscess

and sepsis resolution, and lower rates of complications,

when compared to operative intervention [14-16]. It

should be noted that second attempts at percutaneous

drainage were required in a significant number of pa-

tients described in the above studies and that the duration

of drain management ranged from 6 to 60 days. Our pa-

tient underwent a total of five drainage procedures and

three drainage catheter placement procedures, which

resulted in resolution of the fluid collections. Common

adverse events described with catheter management in-

cluded drains falling out or becoming clogged or dam-

aged, cellulitis at the drain site, and less commonly fis-

tula formation, bleeding, need for re-hospitalization, and

inability to place the drain.

Recognized limitations in the evaluation of this case

include the initiation of antibiotics prior to obtaining

cultures and the polymicrobial nature of the infection.

Intravenous antibiotic therapy was initiated prior to the

culdocentesis procedure from which the S. anginosus

cultures were obtained. This may have limited culture

results, suppressing growth of other involved pathogens.

Prevotella species was also isolated from the culdocente-

sis specimen. Its ability to cause abscesses and bactere-

mia is well documented, particularly in the mouth fol-

lowing invasive proc edures. Since both S. anginosus and

Prevotella both can colonize the oral cavity, a more care-

ful assessment of the patient’s teeth and mouth would

have been helpful despite there being no presenting sym-

ptomatology related to these structures. With regard to

antibiotic selection , the initial empiric use of broad spec-

trum antibiotics is justifiable given the presenting cir-

cumstances. Later, culture-based identification of the

causative pathogens would have allowed for therapeutic

modifications in the event of a suboptimal response, or if

microbial resistance was identified. Fortunately, S. angi-

nosus is sensitive to a wide variety of Gram-positive fo-

cused antimicrobial agents.

In summary, this case report details an unusual viru-

lent infection presenting in an otherwise young healthy

postpartum patient caused by S. anginosus. Because of

the pathologic potential for this organism, it highlights

R. Shabana et al. / Open Journal of Obstetrics and Gynecology 2 (2012) 235-238

238

[7] Salavert, M., Gomez, L., Rodriguez-Carballeira, M., Xer-

cavins, M., Freixas, N. and Garau, J. (1996) Seven-year

review of bacteremia caused by Streptococcus milleri and

other viridans streptococci. European Journal of Clinical

Microbiology & Infectious Diseases, 15, 365-371.

doi:10.1007/BF01690091

the importance of careful laboratory identification and

timely reporting. Given its predilectio n for puru lence and

abscess formation, once identified as a cause for infec-

tion, careful observation for disease progression is re-

quired. Transabdominal percutaneous drainage of acces-

sible abscess pockets, in the otherwise stable parturient,

seems to be a reasonable consideration as a first line

approach. There are presently insufficient data available

in the obstetric literature detailing colonization rates and

the incidence of disease. This limits insight as to the need

for preemptive identification or prophylactic interven-

tio ns, as we do with other known puerper al Streptococcus

pathogens S. agal act i ae and S. pyogenes.

[8] Treszezamsky, A.D. and Feldman, D., Sarabanchong, V.O.

(2011) Concurrent postpartum uterine and abdominal

wall dehiscence and Stretococcus anginosus infection.

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[9] Lampen, R. and Bearman, G. (2005) Epidural abscess

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[10] Cox, R.A., Chen, K., Coykendall, A.L., Wesbecher, P. and

Herson, V.C. (1987) Fatal infection in neonates of 26

weeks’ gestation due to Streptococcus milleri: Report of

two cases. Journal of Clinical Pathology, 40, 190-193.

doi:10.1136/jcp.40.2.190

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