Do I need to repeat cultures for Morganella (Morganella morganii) bacteremia from a urinary tract infection (UTI)?

From the Guidelines

Repeat cultures for Morganella bacteremia from UTI are not necessary if the patient is clinically improving on appropriate antibiotic therapy. The management of Morganella morganii bacteremia from a urinary source should focus on treating the underlying UTI and ensuring the patient's clinical improvement. According to the guidelines, clinicians should repeat urine cultures to guide further management when UTI symptoms persist following antimicrobial therapy 1. However, if the patient is showing signs of clinical improvement, there is no strong evidence to support the routine repetition of blood cultures.

For treatment, antibiotics that Morganella is typically susceptible to should be used, such as carbapenems, third-generation cephalosporins, or fluoroquinolones, guided by susceptibility testing. The typical treatment duration is 7-14 days, depending on clinical response. Ensuring source control by addressing any urinary obstruction or anatomical abnormalities is also crucial. Follow-up blood cultures are indicated only if the patient shows persistent fever, hemodynamic instability, or other signs of ongoing infection after 48-72 hours of appropriate therapy.

Key considerations in the management of recurrent UTIs include:

• Obtaining a pretreatment urine culture when an acute UTI is suspected 1
• Using prior culture data to choose among first-line treatments while culture is pending
• Considering antibiotic resistance patterns in the patient and the community, as well as patient allergies, side effects, and cost
• Avoiding the treatment of asymptomatic bacteriuria, as this can foster antimicrobial resistance and increase the number of recurrent UTI episodes.

In the context of Morganella morganii bacteremia from a urinary source, the focus should be on treating the underlying infection effectively and ensuring the patient's clinical improvement, rather than routinely repeating cultures. The decision to repeat cultures should be guided by the patient's clinical response to treatment, rather than a standard protocol.

From the Research

Morganella Bacteremia from UTI

• The decision to repeat cultures for Morganella bacteremia from a urinary tract infection (UTI) is not explicitly addressed in the provided studies 2, 3, 4, 5, 6.
• However, it is essential to note that Morganella morganii is a Gram-negative bacterium that can cause various infections, including UTIs, and is often associated with antibiotic resistance 3, 4, 5, 6.
• The studies suggest that M. morganii infections can be severe and have a high mortality rate, especially in patients with underlying comorbidities 3, 4, 5.
• Treatment of M. morganii infections typically involves the use of antibiotics, such as gentamicin, ceftazidime, and imipenem, although resistance to these antibiotics has been reported 4, 6.
• In the context of UTIs, it is crucial to identify the causative pathogen and determine its antibiotic susceptibility to guide appropriate treatment 2, 6.
• While the provided studies do not directly address the need to repeat cultures for M. morganii bacteremia from UTI, it is generally recommended to monitor patients with UTIs for clinical improvement and to adjust treatment as needed based on culture and susceptibility results 2, 4.

Antibiotic Resistance and Treatment

• M. morganii has been shown to exhibit resistance to various antibiotics, including first-generation cephalosporins, ampicillin-clavulanate, and fluoroquinolones 3, 4, 6.
• The use of antibiotics, such as gentamicin, ceftazidime, and imipenem, has been recommended for the treatment of M. morganii infections, although resistance to these antibiotics has been reported 4, 6.
• It is essential to perform antibiotic susceptibility testing to guide appropriate treatment and to monitor for the development of resistance 2, 4, 6.

Clinical Considerations

• M. morganii infections can be severe and have a high mortality rate, especially in patients with underlying comorbidities 3, 4, 5.
• Clinicians should be aware of the potential for M. morganii to cause infections, particularly in patients with UTIs, and should consider this pathogen when selecting empiric antibiotic therapy 2, 4, 5.
• Further research is needed to better understand the epidemiology and treatment of M. morganii infections, particularly in the context of UTIs 4, 6.