eMedicine Specialties > Infectious Diseases > Bacterial Infections
Peptostreptococcus Infection: Treatment & Medication
Updated: Jun 17, 2008
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
Treatment
Medical Care
A patient's recovery from anaerobic infection depends on prompt and proper treatment according to the following principles: (1) neutralizing toxins produced by anaerobes, (2) preventing local bacterial proliferation by changing the environment, and (3) limiting the spread of bacteria.
- Control the environment by debriding necrotic tissue, draining pus, improving circulation, alleviating obstruction, and increasing tissue oxygenation. Certain types of adjunctive therapy, such as hyperbaric oxygen therapy, may be useful but remain unproven.
- In many cases, antimicrobial therapy is the only form of therapy required, but it can also be an adjunct to a surgical approach. Because anaerobic bacteria, including peptostreptococci, are generally recovered mixed with aerobic organisms, choose antimicrobial agents that treat both types of pathogens, taking into consideration their aerobic and anaerobic antibacterial spectrum and their availability in oral or parenteral form.
- Penicillin G is most effective for treating anaerobic gram-positive cocci and microaerophilic streptococci.
- Other effective agents include other penicillins, cephalosporins, chloramphenicol, clindamycin, vancomycin, telithromycin, linezolid, quinupristin/dalfopristin, and carbapenems.
- The efficacy of macrolides (eg, erythromycin) and imidazoles (eg, metronidazole) is variable and unpredictable. Imidazoles are ineffective against some anaerobic gram-positive cocci and all aerotolerant strains.
- The newer quinolones are effective against more than 90% of anaerobic cocci; ciprofloxacin is less effective.
- Occasionally, certain strains are resistant to antimicrobials, especially after administration of these agents.
- When mixed with other beta-lactamase–producing bacteria, anaerobic gram-positive cocci and microaerophilic streptococci may survive penicillin or cephalosporin therapy because of the protection provided by the free enzyme. In such instances, antimicrobials with wider spectrums of activity may be more effective.
Surgical Care
In most cases, surgical therapy is critically important. Surgical therapy includes (1) draining abscesses, (2) debriding necrotic tissues, (3) decompressing closed-space infections, and (4) relieving obstructions. If surgical drainage is not used, the infection may persist and serious complications may develop.
Medication
Clinical judgment, personal experience, safety, and expected level of patient compliance should direct the physician in the choice of antimicrobial agents. When choosing antimicrobials for the therapy of mixed infections, their aerobic and anaerobic antibacterial spectrum and their availability in oral or parenteral form should be considered. Some antimicrobials have a limited range of activity.
Aside from susceptibility patterns, other factors influencing the choice of antimicrobial therapy include the pharmacologic characteristics of the various drugs, their toxicity, their effect on the normal florae, and their bactericidal activity. Although identification of the infecting organisms and their antimicrobial susceptibility may be needed for selection of optimal therapy, the clinical setting and gram-stain preparation of the specimen may indicate the types of anaerobes present in the infection and may indicate the nature of the infectious process.
Although the duration of therapy for anaerobic infections is generally longer than for aerobic and facultative infections, the duration must be individualized depending on the patient's response to the therapy. In some cases, the patient may require a 6- to 8-week course. However, therapy may be shortened after proper surgical drainage.19
Because peptostreptococci are often mixed with other aerobic and anaerobic bacteria in the infectious process, broader antimicrobial coverage is often necessary. Furthermore, because of the difficulty in recovering other fastidious anaerobic organisms, they may not be recovered even when cultures are taken.
Antimicrobial agents with broader coverage against anaerobic bacteria, including peptostreptococci, include cefoxitin, clindamycin, carbapenem (eg, imipenem, meropenem, ertapenem), tigecycline, the combination of a penicillin (eg, ticarcillin) with a beta-lactamase inhibitor (ie, clavulanate), and quinolones with anti-anaerobic activity (ie, moxifloxacin).19
An anti–gram-negative enteric agent is generally added to treat Enterobacteriaceae when treating intra-abdominal infections.
Penicillin is added to metronidazole to cover microaerophilic streptococci, peptostreptococci, Actinomyces species, and Arachnia species when treating intracranial and dental infections.
Penicillin is the antimicrobial of choice for bacteremia caused by non beta-lactamase producers; however, if other organisms may be involved in another site, broader coverage is needed.
A macrolide or amoxicillin is added to metronidazole to treat S aureus and aerobic streptococci in upper respiratory tract infections.
Doxycycline is effective against chlamydial and mycoplasmal infections and is added to most regimens when treating pelvic infections.
Oral therapy for peptostreptococci is often substituted for parenteral therapy. Oral agents include clindamycin, amoxicillin and clavulanate, and chloramphenicol.
Antimicrobials
Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Penicillin G (Pfizerpen)
Interferes with synthesis of cell-wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms (beta-lactam).
Adult
10-28 million U/d IV q4h in 6 divided doses
Pediatric
50,000-100,000 U/d IV
Probenecid can increase effects; coadministration with tetracyclines can decrease effects
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Caution in impaired renal function; may cause angioedema, pruritic rash, delayed rash, and gastrointestinal intolerance
Cefoxitin (Mefoxin)
Second-generation cephalosporin indicated for gram-positive cocci and gram-negative rod infections. Infections caused by cephalosporin- or penicillin-resistant gram-negative bacteria may respond.
Adult
2 g IV q6h
Pediatric
40 mg/kg/d IV q6h
Probenecid may increase effects; coadministration with aminoglycosides or furosemide may increase nephrotoxicity (closely monitor renal function)
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Bacterial or fungal overgrowth of nonsusceptible organisms may occur with prolonged use or repeated treatment; caution in previously diagnosed colitis
Cefotetan (Cefotan)
Second-generation cephalosporin indicated for management of infections caused by susceptible gram-positive cocci and gram-negative rods.
Adult
2 g IV q12h
Pediatric
20-40 mg/kg IV q12h for 5-10 d
Consumption of alcohol within 72 h of administration may produce disulfiramlike reactions; may increase hypoprothrombinemic effects of anticoagulants
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Reduce dosage by half with CrCl <10-30 mL/min and by one fourth with CrCl <10 mL/min; bacterial or fungal overgrowth of nonsusceptible organisms may occur with prolonged or repeated therapy
Clindamycin (Cleocin)
Lincosamide for treatment of serious skin and soft tissue staphylococcal infections. Effective against aerobic and anaerobic streptococci (except enterococci). Inhibits bacterial growth, possibly by blocking dissociation of peptidyl t-RNA from ribosomes, causing RNA-dependent protein synthesis to arrest.
Adult
150-300 mg PO q6h
600 mg IV q8h
Pediatric
20-30 mg/kg/d PO divided q6h
25-40 mg/kg/d IV
Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects; antidiarrheals may delay absorption
Documented hypersensitivity; regional enteritis; ulcerative colitis; hepatic impairment; antibiotic-associated colitis
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; commonly associated with Clostridium difficile diarrhea; associated with severe and possibly fatal colitis
Amoxicillin and clavulanate (Augmentin)
Treat bacteria resistant to beta-lactam antibiotics.
Adult
500 mg PO q8h
875 mg PO q12h
Pediatric
40 mg/kg/d PO q8h (tid formulation)
45 mg/kg/d PO q12h (bid formulation)
Coadministration with warfarin or heparin increases risk of bleeding
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Administer for a minimum of 10 d to eliminate organism and prevent sequelae (endocarditis, rheumatic fever); following treatment, perform cultures to confirm eradication of streptococci
Ticarcillin and clavulanate potassium (Timentin)
Inhibit biosynthesis of cell-wall mucopeptide and are effective during stage of active growth. Contains 4.7-5 mEq of Na+/g.
Adult
3.1 g IV q4-6h
Pediatric
200-300 mg/kg/d IV q4-6h
Tetracyclines may decrease effects; high concentrations of ticarcillin may physically inactivate aminoglycosides if administered in same IV line; effects are synergistic when administered concurrently with aminoglycosides; probenecid may increase penicillin levels
Documented hypersensitivity; severe pneumonia, bacteremia, pericarditis, emphysema, meningitis, and purulent or septic arthritis should not be treated with oral penicillin during acute stage
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Perform CBC counts prior to initiation of therapy and at least weekly during therapy; monitor for liver function abnormalities by measuring AST and ALT during therapy; exercise caution in hepatic insufficiency; perform urinalysis, BUN, and creatinine determinations during therapy, and adjust dose if values become elevated; monitor blood levels to avoid possible neurotoxic reactions
Chloramphenicol (Chloromycetin)
Binds to 50S bacterial-ribosomal subunits and inhibits bacterial growth by inhibiting protein synthesis. Effective against gram-negative and gram-positive bacteria.
Adult
500 mg to 1 g IV q6h; not to exceed 4 g/d
Pediatric
80-100 mg/kg/d IV
Concurrently with barbiturates, serum levels may decrease while barbiturate levels may increase, causing toxicity; manifestations of hypoglycemia may occur with sulfonylureas; rifampin may reduce serum levels, presumably through hepatic enzyme induction; may increase effects of anticoagulants; may increase serum hydantoin levels, possibly resulting in toxicity; hydantoins may either increase or decrease levels
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Use only for indicated infections; rarely, serious or fatal blood dyscrasias (aplastic anemia, hypoplastic anemia, thrombocytopenia, granulocytopenia) can occur; leukopenia, thrombocytopenia, and anemia are dose-related effects; adjust dose in severe liver or kidney dysfunction; caution in pregnancy at term or during labor because of potential toxic effects on fetus (gray baby syndrome)
Imipenem and cilastatin (Primaxin)
For treatment of multiorganism infections in which other agents do not have wide-spectrum coverage or are contraindicated because of potential for toxicity.
Adult
500-750 mg IV q6h; not to exceed 3 g/d
Pediatric
15-25 mg/kg/d IV q6h; not to exceed 2 g/d
Coadministration with cyclosporine may increase adverse CNS effects of both agents; coadministration with ganciclovir may result in generalized seizures
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Adjust dose in renal insufficiency; high doses can cause seizures and renal failure, especially in elderly patients and those with prior seizure disorders
Meropenem (Merrem)
Bactericidal broad-spectrum carbapenem antibiotic that inhibits cell-wall synthesis. Effective against most gram-positive and gram-negative bacteria. Has slightly increased activity against gram-negatives and slightly decreased activity against staphylococci and streptococci compared with imipenem.
Adult
1 g IV q8h
Pediatric
<3 months: Not recommended
>3 months: 40 mg/kg IV q8h
Probenecid may inhibit renal excretion, increasing levels
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Pseudomembranous colitis and thrombocytopenia may occur, requiring immediate discontinuation of medication
Ertapenem (Invanz)
Bactericidal activity results from inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin-binding proteins. Stable against hydrolysis by a variety of beta-lactamases, including penicillinases, cephalosporinases, and extended-spectrum beta-lactamases. Hydrolyzed by metallo-beta-lactamases.
Adult
1 g/d for 14 d if given IV and for 7 d if given IM; infuse over 30 min if given IV
Pediatric
Not established
Probenecid may reduce renal clearance and increase half-life but benefit is minimal and does not justify coadministration
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Pseudomembranous colitis may occur; seizures and adverse CNS reactions may occur; when using with lidocaine to administer IM, avoid inadvertent injection into blood vessel
Moxifloxacin (Avelox)
Inhibits the A subunits of DNA gyrase, resulting in inhibition of bacterial DNA replication and transcription.
Adult
400 mg PO/IV qd
Pediatric
<18 years: Not recommended
>18 years: Administer as in adults
Antacids and electrolyte supplements reduce absorption; loop diuretics, probenecid, and cimetidine increase serum levels; NSAIDs enhance CNS stimulating effect
May increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT); ferrous sulfate decreases bioavailability (administer moxifloxacin 4 h prior or 8 h following ferrous sulfate); coadministration with drugs that prolong QTc interval (quinidine, procainamide, amiodarone, sotalol, erythromycin, tricyclic antidepressants) increase risk of life-threatening arrhythmia
Documented hypersensitivity; known Q-T prolongation; concurrent administration of drugs that cause Q-T prolongation
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
In prolonged therapy, periodically evaluate organ system functions (eg, renal, hepatic, hematopoietic); superinfections may occur with prolonged or repeated antibiotic therapy; fluoroquinolones have induced seizures in CNS disorders and caused tendinitis or tendon rupture
Tigecycline (Tygacil)
A glycylcycline antibiotic that is structurally similar to tetracycline antibiotics. Inhibits bacterial protein translation by binding to 30S ribosomal subunit, and blocks entry of amino-acyl tRNA molecules in ribosome A site. Complicated intra-abdominal infections caused by C freundii, E cloacae, E coli, K oxytoca, K pneumoniae, E faecalis (vancomycin-susceptible isolates only), S aureus (methicillin-susceptible isolates only), S anginosus group (includes S anginosus, S intermedius, and S constellatus), B fragilis, B thetaiotaomicron, B uniformis, B vulgatus, C perfringens, and P micros.
Adult
Infuse each dose over 30-60 min
100 mg IV once, then 50 mg IV q12h
Severe hepatic impairment (ie, Child Pugh class C): 100 mg IV once, then 25 mg IV q12h
Pediatric
<18 years: Not established
>18 years: Administer as in adults
Coadministration decreases warfarin clearance and increases warfarin Cmax and AUC (monitor aPTT and INR); coadministration of antibiotics with oral contraceptives may decrease contraceptive effect
Documented hypersensitivity
Pregnancy
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions
Caution in severe hepatic impairment (reduce dose); may adversely effect tooth development; may permit clostridial overgrowth, resulting in antibiotic-associated colitis; may have adverse effects similar to those of tetracyclines (eg, photosensitivity, pseudotumor cerebri, pancreatitis, antianabolic action)
More on Peptostreptococcus Infection |
| Overview: Peptostreptococcus Infection |
| Differential Diagnoses & Workup: Peptostreptococcus Infection |
 Treatment & Medication: Peptostreptococcus Infection |
| Follow-up: Peptostreptococcus Infection |
| References |
| « Previous Page | Next Page » |
References
Brook I. Anaerobic Infections. In: Diagnosis and Management. 4th Edition. New York: Informa Healthcare USA inc; 2007.
Finegold SM. Anaerobic Bacteria in Human Disease. Orlando, Fla: Academic Press; 1977.
Bourgault AM, Rosenblatt JE, Fitzgerald RH. Peptococcus magnus: a significant human pathogen. Ann Intern Med. Aug 1980;93(2):244-8. [Medline].
Bartlett JG. Anaerobic bacterial infections of the lung and pleural space. Clin Infect Dis. Jun 1993;16 Suppl 4:S248-55. [Medline].
Brook I. Recovery of anaerobic bacteria from clinical specimens in 12 years at two military hospitals. J Clin Microbiol. Jun 1988;26(6):1181-8. [Medline].
Martin WJ. Isolation and identification of anaerobic bacteria in the clinical laboratory. A 2-year experience. Mayo Clin Proc. May 1974;49(5):300-8. [Medline].
Brook I. Peptostreptococcal infection in children. Scand J Infect Dis. 1994;26(5):503-10. [Medline].
Murdoch DA. Gram-positive anaerobic cocci. Clin Microbiol Rev. Jan 1998;11(1):81-120. [Medline].
Jousime-Somers H, Summanen P, Citron DM, et al. Wadsworth-KTL Anaerobic Bacteriology Manual. 6th ed. Belmont, Calif: Star Publishing; 2002.
Araki H, Kuriyama T, Nakagawa K, Karasawa T. The microbial synergy of Peptostreptococcus micros and Prevotella intermedia in a murine abscess model. Oral Microbiol Immunol. Jun 2004;19(3):177-81. [Medline].
Brook I, Walker RI. Pathogenicity of anaerobic gram-positive cocci. Infect Immun. Aug 1984;45(2):320-4. [Medline].
Brook I. Anaerobic bacterial bacteremia: 12-year experience in two military hospitals. J Infect Dis. Dec 1989;160(6):1071-5. [Medline].
Saini S, Gupta N, Aparna, Seema, Sachdeva OP. Bacteriological study of paediatric and adult chronic suppurative otitis media. Indian J Pathol Microbiol. Jul 2005;48(3):413-6. [Medline].
Brook I. Microbiology of acute and chronic maxillary sinusitis associated with an odontogenic origin. Laryngoscope. May 2005;115(5):823-5. [Medline].
Blairon L, De Gheldre Y, Delaere B, Sonet A, Bosly A, Glupczynski Y. A 62-month retrospective epidemiological survey of anaerobic bacteraemia in a university hospital. Clin Microbiol Infect. Jun 2006;12(6):527-32. [Medline].
Song Y, Liu C, McTeague M, Vu A, Liu JY, Finegold SM. Rapid identification of Gram-positive anaerobic coccal species originally classified in the genus Peptostreptococcus by multiplex PCR assays using genus- and species-specific primers. Microbiology. Jul 2003;149:1719-27. [Medline].
Aldridge KE, Ashcraft D, Cambre K, Pierson CL, Jenkins SG, Rosenblatt JE. Multicenter survey of the changing in vitro antimicrobial susceptibilities of clinical isolates of Bacteroides fragilis group, Prevotella, Fusobacterium, Porphyromonas, and Peptostreptococcus species. Antimicrob Agents Chemother. Apr 2001;45(4):1238-43. [Medline].
Wexler HM, Finegold SM. Current susceptibility patterns of anaerobic bacteria. Yonsei Med J. Dec 1998;39(6):495-501. [Medline].
Brook I. Treatment of anaerobic infection. Expert Rev Anti Infect Ther. Dec 2007;5(6):991-1006. [Medline].
Malik NN, Goh D, McLean C, Huchzermeyer P. Orbital cellulitis caused by Peptostreptococcus. Eye. Jun 2004;18(6):643-4. [Medline].
Further Reading
Keywords
Peptostreptococcus infection, anaerobic cocci, anaerobic gram-positive cocci, peptococci, peptostreptococci, Peptococcus, microaerophilic streptococci, Peptostreptococcus magnus, P magnus, Peptostreptococcus asaccharolyticus, P asaccharolyticus, Peptostreptococcus anaerobius, P anaerobius, Peptostreptococcus prevotii, P prevotii, Peptostreptococcus micros, P micros, Streptococcus anginosus, S anginosus, Streptococcus milleri, S milleri, Streptococcus constellatus, S constellatus, Streptococcus intermedius, S intermedius, Streptococcus morbillorum, S morbillorum, Peptostreptococcus hydrogenalis, P hydrogenalis, Staphylococcus aureus, S aureus, Streptococcus, Veillonella, Fusobacterium, Porphyromonas, Prevotella, Prevotella bivia, P bivia, Prevotella disiens, P disiens, Escherichia coli, E coli, Bacteroides fragilis, B fragilis
