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Staphylococcus Saprophyticus

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Last Update: October 27, 2018.

Introduction

Staphylococcus saprophyticus is a Gram-positive, coagulase negative, non-hemolytic coccus that is a common cause of uncomplicated urinary tract infections (UTIs), particularly in young sexually active females. Less commonly, it is responsible for complications including acute pyelonephritis, urethritis, epididymitis, and prostatitis.

An acute uncomplicated UTI is characterized by dysuria and frequency in an immunocompetent, non-pregnant adult female and is the most common bacterial infection in women. A complicated infection typically involves a patient that is immunocompromised, elderly, male, pregnant, diabetic, and/or with urologic abnormalities such as indwelling catheters or kidney disease.

S. saprophyticus can be differentiated from another coagulase-negative staphylococcus by its resistance to Novobiocin. Like other uropathogens, S. saprophyticus utilizes urease to produce ammonia. However, unlike many of these organisms, it cannot reduce nitrate.

S. saprophyticus is part of the normal human flora that colonizes the perineum, rectum, urethra, cervix, and gastrointestinal tract. It has also been found that S. saprophyticus is a common gastrointestinal flora in pigs and cows and thus may be transferred to humans through eating these respective foods.

Etiology

S. saprophyticus is the second most common cause of community-acquired urinary tract infections, after Escherichia coli. In females ages 16 to 25, it causes up to 42% of all infections. Over 40% of all young, sexually active women contain S. saprophyticus as part of their normal genitourinary flora.

Patients with nosocomial UTIs, the elderly, pregnant patients, and those with urinary catheterization have an increased incidence S. saprophyticus colonization. Men have a lower incidence of S. saprophyticus infections.

General risk factors for UTI’s include history of recurrent UTIs, female sex, recent sexual intercourse, pregnancy, neurogenic bladder, indwelling catheter, and benign prostatic hypertrophy.

S. saprophyticus is also a common culprit involved in polymicrobial UTIs. Polymicrobial infections are more likely to occur in patients that are immunocompromised, elderly, those who have diabetes, have indwelling catheters, HIV, and/or malignancies. Polymicrobial infections are less common in young, healthy, sexually active females.

Epidemiology

In the United States, urinary discomfort is a common complaint in patients seeking medical attention. UTIs are one of the top 10 diagnoses made in emergency departments annually. Nearly half of all women will experience a UTI in their lifetime, and between 5% and 20% of non-hospitalized patients, the infection will be due to S. saprophyticus. Despite highly successful treatment rates, up to 60% of all patients will experience a recurrent UTI within one year.

Pathophysiology

Bacterial colonization of the bladder and ureter epithelium by S. Saphrophyticus occurs via several different types of adhesins. These include hemagglutinins with autolytic and adhesive properties, as well as surface-associated lipase that forms fimbria-like surface appendages, helping the bacteria to maintain tight adherence to these surfaces.

It is suspected that the high survivability of S. saprophyticus inside the urinary tract is in part due to the adhesins anchored within the cell wall, allowing the organism to effectively adhere and colonize the uroepithelium, together with urease, which contributes to the persistent growth of the infection.

Some strains of S. Saprophyticus have the ability to create biofilms, increasing their virulence, especially in patients with catheters. Once biofilms have been produced, antibiotic resistance is exacerbated. In these cases, S. Saprophyticus may be resistant to vancomycin and only effectively treated via linezolid.

History and Physical

The characteristic history of dysuria, urinary frequency, urinary urgency, and suprapubic pain will be common in symptomatic UTI patients. In those patients with pyelonephritis, back or flank pain, nausea, and fever or chills may also be present.

Physical examination may reveal suprapubic tenderness, in 10% to 20% of cases, and should include urine specimen for analysis. However, in most cases of uncomplicated UTI, a physical examination is unremarkable. In complicated cases or pyelonephritis, patients may present with fever, tachycardia, and/or costovertebral angle tenderness.

Evaluation

The diagnosis of S. saprophyticus requires a confirmatory urine culture. A positive culture is indicated by greater than 100,000 colony forming units per mL, with a sensitivity and specificity of more than 90%.

UTI, in general, may be diagnosed more cost-effectively with a urine dipstick alone. A dipstick that is positive for leukocytes esterase and/or nitrites is the most simplistic method of UTI diagnosis. In cases of negative dipstick results, and high clinical suspicion, a bacterial urine culture should also be obtained.

  • An adequate urine sample should be obtained from a mid-stream catch or straight catheterization, which more effectively avoids contamination.

Imaging is not necessary for cases of uncomplicated UTIs. If renal pathology, such as pyelonephritis, is suspected a CT scan is the most sensitive modality for demonstrating complications such as hydronephrosis or renal abscess.

Treatment / Management

Treatment with outpatient antibiotics is indicated in symptomatic or complicated UTIs and pyelonephritis. It is important to take into consideration specific local resistance patterns when choosing appropriate antibiotic coverage.

The antibiotic of choice in uncomplicated S. saprophyticus UTIs is nitrofurantoin (Macrobid) 100 mg orally twice daily for five days, or for seven days in complicated cases. Trimethoprim-sulfamethoxazole (TMP-SMX) 160 mg/800 mg by mouth twice daily for three days may be given alternatively in uncomplicated cases.

Symptomatic treatment for pain and nausea should also be addressed.  Acute uncomplicated UTIs are unlikely to cause renal injury. Thus NSAIDs are a preferred analgesic. Pyridium may also be given to alleviate associated dysuria. Ondansetron or Promethazine are commonly prescribed anti-emetics. Most patients will notice symptomatic relief within 36 hours from antibiotic treatment alone.

Patients who are hemodynamically unstable, have associated kidney injury, abscess formation, or emphysematous pyelonephritis, have failed outpatient treatment, have intractable nausea, vomiting, or pain, are unable to tolerate oral intake, or are unable to comply with medical treatment may require admission.

Differential Diagnosis

Other diagnoses include non-S. saprophyticus UTI or cystitis, urethritis, pyelonephritis, or nephrolithiasis.

Prognosis

The majority of S. saprophyticus infections can be adequately treated with antibiotics. However, if left untreated, they may progress to pyelonephritis. Untreated pyelonephritis may lead to further complications, such as renal insufficiency.

Pearls and Other Issues

It is important to note that the diagnosis of UTI based on the combination of both leukocyte esterase and nitrites, will miss cases caused by S. saprophyticus. Like most other gram-positive uropathogens, S. saprophyticus does not reduce nitrate to nitrite.

S. saprophyticus has resistance to antibiotic regimes commonly prescribed and effective for E. coli induced UTIs, including ampicillin, ceftriaxone, cephalexin, and ciprofloxacin. In cases where UTI symptoms persist following treatment with one of the previously mentioned antibiotics, S. saprophyticus should be highly suspected.

Questions

To access free multiple choice questions on this topic, click here.

References

1.
Pailhoriès H, Cassisa V, Chenouard R, Kempf M, Eveillard M, Lemarié C. Staphylococcus saprophyticus: Which beta-lactam? Int. J. Infect. Dis. 2017 Dec;65:63-66. [PubMed: 29030135]
2.
Lala V, Minter DA. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Oct 27, 2018. Cystitis, Acute.
3.
Heytens S, Boelens J, Claeys G, DeSutter A, Christiaens T. Uropathogen distribution and antimicrobial susceptibility in uncomplicated cystitis in Belgium, a high antibiotics prescribing country: 20-year surveillance. Eur. J. Clin. Microbiol. Infect. Dis. 2017 Jan;36(1):105-113. [PubMed: 27639858]
4.
de Oliveira A, Cataneli Pereira V, Pinheiro L, Moraes Riboli DF, Benini Martins K, Ribeiro de Souza da Cunha Mde L. Antimicrobial Resistance Profile of Planktonic and Biofilm Cells of Staphylococcus aureus and Coagulase-Negative Staphylococci. Int J Mol Sci. 2016 Sep 01;17(9) [PMC free article: PMC5037702] [PubMed: 27598130]
5.
Hashmi A, Abdullah FE, Abdullah NE, Kazmi SU. Species Identification and Antibiotic Susceptibilities of Coagulase- Negative Staphylococci Isolated from Urinary Tract Infection Specimens. J Coll Physicians Surg Pak. 2016 Jul;26(7):581-4. [PubMed: 27504549]
6.
Kline KA, Lewis AL. Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract. Microbiol Spectr. 2016 Apr;4(2) [PMC free article: PMC4888879] [PubMed: 27227294]
7.
Hisano M, Bruschini H, Nicodemo AC, Gomes CM, Lucon M, Srougi M. The Bacterial Spectrum and Antimicrobial Susceptibility in Female Recurrent Urinary Tract Infection: How Different They Are From Sporadic Single Episodes? Urology. 2015 Sep;86(3):492-7. [PubMed: 26163810]
8.
Becker K, Heilmann C, Peters G. Coagulase-negative staphylococci. Clin. Microbiol. Rev. 2014 Oct;27(4):870-926. [PMC free article: PMC4187637] [PubMed: 25278577]
9.
Kazi YF, Saleem S, Kazi N. Investigation of vaginal microbiota in sexually active women using hormonal contraceptives in Pakistan. BMC Urol. 2012 Aug 18;12:22. [PMC free article: PMC3492163] [PubMed: 22901000]
10.
Hashmi A, Abdullah FE, Abdullah NE, Kazmi SU. Species Identification and Antibiotic Susceptibilities of Coagulase- Negative Staphylococci Isolated from Urinary Tract Infection Specimens. J Coll Physicians Surg Pak. 2016 Jul;26(7):581-4. [PubMed: 27504549]
11.
Kuroda M, Yamashita A, Hirakawa H, Kumano M, Morikawa K, Higashide M, Maruyama A, Inose Y, Matoba K, Toh H, Kuhara S, Hattori M, Ohta T. Whole genome sequence of Staphylococcus saprophyticus reveals the pathogenesis of uncomplicated urinary tract infection. Proc. Natl. Acad. Sci. U.S.A. 2005 Sep 13;102(37):13272-7. [PMC free article: PMC1201578] [PubMed: 16135568]
12.
Bertoni G, Pessacq P, Guerrini MG, Calmaggi A, Barberis F, Jorge L, Bonvehi P, Temporiti E, Herrera F, Obed M, Alcorta B, Farías J, Mykietiuk A. [Etiology and antimicrobial resistance of uncomplicated urinary tract infections]. Medicina (B Aires). 2017;77(4):304-308. [PubMed: 28825574]
13.
de Sousa VS, da-Silva APS, Sorenson L, Paschoal RP, Rabello RF, Campana EH, Pinheiro MS, Dos Santos LOF, Martins N, Botelho ACN, Picão RC, Fracalanzza SEL, Riley LW, Sensabaugh G, Moreira BM. Staphylococcus saprophyticus Recovered from Humans, Food, and Recreational Waters in Rio de Janeiro, Brazil. Int J Microbiol. 2017;2017:4287547. [PMC free article: PMC5463105] [PubMed: 28630628]
14.
Jorgensen S, Zurayk M, Yeung S, Terry J, Dunn M, Nieberg P, Wong-Beringer A. Emergency Department Urinary Antibiograms Differ by Specific Patient Group. J. Clin. Microbiol. 2017 Sep;55(9):2629-2636. [PMC free article: PMC5648700] [PubMed: 28615465]
15.
Davenport M, Mach KE, Shortliffe LMD, Banaei N, Wang TH, Liao JC. New and developing diagnostic technologies for urinary tract infections. Nat Rev Urol. 2017 May;14(5):296-310. [PMC free article: PMC5473291] [PubMed: 28248946]
16.
Moy E, Coffey RM, Moore BJ, Barrett ML, Hall KK. Length of stay in EDs: variation across classifications of clinical condition and patient discharge disposition. Am J Emerg Med. 2016 Jan;34(1):83-7. [PubMed: 26603268]
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Bookshelf ID: NBK482367PMID: 29493989

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