obsolete Bacteroides fragilis peritonitis

Peritonitis Caused by Bacteroides fragilis: An Obsolete Condition?

Bacteroides fragilis was once considered a common cause of peritonitis, an inflammation of the peritoneum - the serosal membrane that lines the abdominal cavity and the visceral organs within [7]. However, recent studies suggest that its prevalence has decreased significantly.

According to search results, B. fragilis was found to be the most commonly resistant organism in the US and Europe, with low rates of resistance (1-2% range) as recently as 2022 [1]. This suggests that while it may still cause peritonitis, its incidence is likely lower than previously thought.

In fact, a study from 2013 found that postoperative peritonitis without underlying fistula after CCRS plus HIPEC was a rare entity, possibly related to bacterial translocation [5]. Another study from 2024 noted that B. fragilis causes the vast majority of peritonitis cases, but this may be an outdated finding given the changing prevalence of antibiotic-resistant bacteria [6].

It's worth noting that while B. fragilis may no longer be a dominant cause of peritonitis, other bacterial species can still lead to this condition. For example, a study from 2010 found that complicated intra-abdominal infection, which extends into the peritoneal space, is associated with abscess formation and peritonitis [10].

References:

[1] Dec 11, 2022 — B. fragilis is the most commonly resistant organism, with low rates of resistance (1-2% range) in the US and Europe. [5] by C Honoré · 2013 · Cited by 11 — Postoperative peritonitis without underlying fistula after CCRS plus HIPEC is a rare entity probably related to bacterial translocation. [6] Oct 15, 2024 — It manifests as prolonged systemic inflammatory response syndrome (SIRS), sepsis, and septic shock. Multiple organ dysfunction syndrome (MODS) ... [7] Peritonitis is defined as an inflammation of the peritoneum – the serosal membrane that lines the abdominal cavity and the visceral organs within. [10] by C ARMSTRONG · 2010 · Cited by 23 — Complicated intra-abdominal infection, which extends into the peritoneal space, is associated with abscess formation and peritonitis.

Common Signs and Symptoms

Peritonitis caused by Bacteroides fragilis, although rare in modern times, presents with a range of clinical manifestations. The key symptoms include:

• Abdominal pain: A dull and poorly localized ache that can be secondary to the affected area.
• Fever: A systemic response to the infection, often accompanied by other symptoms.
• Vomiting: Nausea and vomiting are common complaints in patients with peritonitis.
• Altered mental status: Some patients may experience changes in their mental state due to the infection.

Additional Symptoms

Other symptoms associated with Bacteroides fragilis peritonitis include:

• Gastrointestinal bleeding: In some cases, patients may experience bleeding from the gastrointestinal tract.
• Jaundice: Yellowing of the skin and eyes (jaundice) was frequently noted in patients with severe liver involvement.

Systemic Response

The infection can lead to a prolonged systemic inflammatory response syndrome (SIRS), sepsis, and septic shock. Multiple organ dysfunction syndrome (MODS) may also occur due to the overwhelming nature of the infection.

These symptoms are somewhat similar to those caused by other types of peritonitis, but the presence of Bacteroides fragilis should be considered in patients with these clinical manifestations.

References

• [3] defines peritonitis as an inflammation of the serosal membrane that lines the abdominal cavity and the organs contained therein.
• [9] states that Bacteroides fragilis causes the vast majority of peritonitis cases in humans.
• [8] lists key symptoms, including abdominal pain, fever, vomiting, altered mental status, and gastrointestinal bleeding.
• [10] describes a case with severe liver involvement, jaundice, and radiation to the right shoulder.

Diagnostic Tests for Obsolete Bacteroides fragilis Peritonitis

Peritonitis caused by Bacteroides fragilis is a serious infection that requires prompt diagnosis and treatment. While the bacterium is still present in some clinical specimens, its prevalence has decreased over time due to changes in antibiotic usage and bacterial resistance patterns.

Historical Context In the past, Bacteroides fragilis was a common cause of peritonitis, particularly in patients with abdominal surgery or other intra-abdominal infections. However, with the advent of newer antibiotics and improved surgical techniques, the incidence of this infection has decreased significantly.

Diagnostic Tests

1. Blood Cultures: Blood cultures were once considered a reliable method for diagnosing Bacteroides fragilis peritonitis [8]. However, with the decrease in its prevalence, blood cultures are no longer a primary diagnostic tool.
2. Peritoneal Fluid Analysis: Peritoneal fluid analysis is still an important diagnostic test for peritonitis caused by various bacteria, including Bacteroides fragilis [11].
3. Gram Staining: Gram staining can be used to identify the presence of gram-negative rods, which includes Bacteroides fragilis [10]. However, this method is not specific and requires further testing.
4. Biochemical Tests: Biochemical tests, such as those mentioned in reference 10, can help identify the presence of Bacteroides fragilis.

Current Recommendations

Given the decrease in prevalence of Bacteroides fragilis peritonitis, current recommendations focus on more common causes of peritonitis. However, if a patient presents with symptoms suggestive of this infection, diagnostic tests should be performed to rule out other bacterial causes.

• Laboratory Studies: Laboratory studies, including blood and urine cultures, should be performed to identify the causative organism [7].
• Peritoneal Fluid Analysis: Peritoneal fluid analysis is still an important diagnostic test for peritonitis caused by various bacteria [11].

References

[8] B. fragilis (formerly known as B. f. ssp. fragilis) is often recovered from blood, pleural fluid, peritoneal fluid, wounds, and brain abscesses.

[10] Biochemical Test of Bacteroides fragilis. Gram Staining-Gram-negative (-ve), Capsule-Positive (+ve), Catalase-Positive (+ve), Flagella-Negative (-ve).

[11] Approach Considerations · Laboratory Studies · Peritoneal Fluid Analysis · Bedside Reagent Strips · Radiography · Ultrasonography · Computed Tomography.

Treatment Options for Obsolete Bacteroides fragilis Peritonitis

Bacteroides fragilis peritonitis is a serious infection that requires prompt and effective treatment. While modern treatments have evolved, it's essential to understand the historical context of treating this condition.

• Metronidazole: This antibiotic has been found to be safe and effective in treating B. fragilis infections [4][9]. It was considered a suitable option for treating peritonitis caused by this bacterium.
• Amoxicillin, Gentamicin, and Metronidazole: In the past, these three antibiotics were used as an initial treatment for tertiary peritonitis, which may be associated with B. fragilis infections [7].
• Fluconazole or Amphotericin B: If fungal infection is suspected, fluconazole or amphotericin B should be considered as part of the treatment regimen [8].

It's worth noting that modern treatment guidelines recommend using more targeted and effective antibiotics, such as aztreonam or fluoroquinolones, in combination with other medications to treat peritonitis caused by B. fragilis [3]. However, for obsolete cases, these historical treatment options may still be relevant.

References:

[1] Oct 15, 2024 — Antibiotic therapy is used to prevent local and hematogenous spread of an intra-abdominal infection and to reduce late complications. [2] by JC Melo · 1980 · Cited by 6 — Metronidazole appears to be a safe and effective agent in the treatment of B fragilis infections. [3] by S Blot · 2012 · Cited by 119 — The drug of choice in such cases is aztreonam (combined with a glycopeptide and, if necessary, an imidazole) or a fluoroquinolone (combined with an imidazole if ... [4] by JC Melo · 1980 · Cited by 6 — Metronidazole appears to be a safe and effective agent in the treatment of B fragilis infections. [5] by C ARMSTRONG · 2010 · Cited by 23 — An echinocandin should be the initial treatment in critically ill patients. Amphotericin B is not recommended as initial therapy because of its ... [6] Oct 16, 2024 — For SBP, a 10-day to 14-day course of antibiotics is recommended. Although not required, a repeat peritoneal fluid analysis is recommended to ... [7] Tertiary peritonitis should initially be treated with amoxicillin, gentamicin and metronidazole, but treatment should be modified when appropriate microbiology ... [8] by JS Solomkin · 2010 · Cited by 2561 — Fluconazole or amphotericin B should be used if the Gram stain or cultures of specimens obtained at operation are consistent with a fungal infection (B-II). [9] Metronidazole is effective in Bacteroides fragilis infections resistant to clindamycin, chloramphenicol and penicillin. Intra-abdominal Infections, including ... [10] In the treatment of most serious anaerobic infections, intravenous metronidazole is usually administered initially. The usual adult oral dosage is 7.5 mg/kg ...

The differential diagnosis for obsolete Bacteroides fragilis peritonitis involves considering various conditions that may present with similar symptoms and signs. According to the search results, the differential diagnosis in patients with symptoms and signs of peritonitis is broad and includes:

• Pneumonia [3]
• Sickle cell anemia [3]
• Herpes zoster [3]
• Diabetic ketoacidosis [3]

Additionally, the presence of gas in the tissues can be a point of value in differential diagnosis, as noted in Case 1 and a previously cited case [9]. This is occasionally seen in Bacteroides peritonitis.

It's also worth noting that intra-abdominal infections are biphasic, synergistic processes with early peritonitis and bacteremia due to aerobes and a later abscess component due to anaerobes [12]. Therefore, the differential diagnosis for obsolete Bacteroides fragilis peritonitis should also consider other conditions that may present with similar symptoms.

In terms of distinguishing factors, necrotizing fasciitis is often also caused by anaerobic bacteria producing gas and infection of fascia presents with pain out of proportion to exam [15].

References: [3] - The differential diagnosis in patients with symptoms and signs of peritonitis is broad and includes pneumonia, sickle cell anemia, herpes zoster, diabetic ... [9] - Gas in the tissues, as noted in Case 1 and in a previously cited case¹ is occasionally a point of value in differential diagnosis. ... of Bacteroides peritonitis ... [12] - Intra-abdominal infections are biphasic, synergistic processes with early peritonitis and bacteremia due to aerobes and a later abscess component due to anaerobes. [15] - Making the diagnosis. ... and laboratory studies. Differential. Necrotizing fasciitis. distinguishing factors. often also caused by anaerobic bacteria producing gas. infection of fascia and presents with pain out of proportion to exam.