From the Guidelines
Morganella morganii infections should be treated with antibiotics such as ciprofloxacin, with consideration of the patient's overall clinical picture and potential for antibiotic resistance, as evidenced by a recent case study where a patient with a complex prosthetic joint infection caused by M. morganii, among other organisms, was successfully managed with long-term antimicrobial therapy including ciprofloxacin 1.
Key Considerations
- M. morganii is a gram-negative bacterium that can cause opportunistic infections, particularly in immunocompromised patients or those with underlying conditions.
- Treatment usually involves antibiotics, with dosing based on infection severity, site, and patient factors.
- Antibiotic susceptibility testing is crucial as M. morganii naturally produces AmpC beta-lactamases, making it resistant to many penicillins and first-generation cephalosporins.
- Prevention strategies include proper wound care, catheter management, and infection control practices.
Treatment Options
- Fluoroquinolones (ciprofloxacin) are a potential treatment option for M. morganii infections, as seen in the case study where a patient was successfully treated with ciprofloxacin and pristinamycin 1.
- Third-generation cephalosporins (ceftriaxone) or carbapenems (meropenem) may also be considered, but antibiotic resistance patterns should be taken into account.
- The use of ceftolozane/tazobactam, a new antibiotic approved for the treatment of complicated intra-abdominal infections, may be considered in certain cases, although its effectiveness against M. morganii is not explicitly stated in the available evidence 1.
Important Factors
- Early identification and appropriate antibiotic therapy are essential for successful treatment of M. morganii infections, especially in vulnerable populations.
- The patient's overall clinical picture, including the presence of underlying conditions and potential for antibiotic resistance, should be considered when selecting a treatment option.
- Long-term antimicrobial therapy may be necessary in complex cases, such as prosthetic joint infections, to ensure successful management of the infection 1.
From the FDA Drug Label
The following in vitro data are available, but their clinical significance is unknown At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for meropenem against isolates of similar genus or organism group. However, the efficacy of meropenem in treating clinical infections caused by these bacteria have not been established in adequate and well-controlled clinical trials ... Morganella morganii
The following in vitro data are available, but their clinical significance is unknown At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for piperacillin and tazobactam against isolates of similar genus or organism group However, the efficacy of piperacillin and tazobactam in treating clinical infections caused by these bacteria has not been established in adequate and well-controlled clinical trials ... Morganella morganii
Morganella morganii is listed as a microorganism that exhibits an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for meropenem and piperacillin-tazobactam. However, the efficacy of these drugs in treating clinical infections caused by Morganella morganii has not been established in adequate and well-controlled clinical trials 2, 2, 3.
- Key points:
- In vitro activity: Meropenem and piperacillin-tazobactam have in vitro activity against Morganella morganii.
- Clinical efficacy: The clinical efficacy of meropenem and piperacillin-tazobactam in treating Morganella morganii infections has not been established.
- Susceptibility testing: Susceptibility testing is necessary to determine the effectiveness of these drugs against Morganella morganii.
From the Research
Overview of Morganella morganii
- Morganella morganii is a Gram-negative, rod-shaped, facultative anaerobic bacillus that can cause serious infections in humans, especially in those with compromised immune systems 4, 5, 6.
- It is commonly found in the human gut commensal microbiota, but can become opportunistic and cause infections in certain conditions 4, 7.
Infections Caused by Morganella morganii
- M. morganii can cause a variety of infections, including bloodstream infections, skin and soft tissue infections, pyelonephritis, female genital tract infections, pneumonia, and gangrenous appendicitis 4, 5, 7, 6, 8.
- The most common symptoms of M. morganii infections include fever, cough, shortness of breath, vomiting, and fatigue 5.
Antibiotic Resistance and Treatment
- M. morganii is often resistant to multiple antibiotics, including ciprofloxacin, trimethoprim/sulfamethoxazole, gentamicin, amoxicillin, nitrofurantoin, and colistin 4, 5, 6.
- The most common treatment for M. morganii bacteremia is carbapenems, followed by aminoglycosides, ciprofloxacin, and colistin 5.
- Source control measures, such as surgery, line removal, drainage, and tissue removal, are also important for improving outcomes 5.
Epidemiology and Risk Factors
- M. morganii infections are more common in elderly patients and those with comorbidities, such as diabetes, renal disease, and congestive heart failure 5, 8.
- The incidence of M. morganii bloodstream infections increases with advancing age, and the 30-day all-cause case fatality rate is around 21.2% 8.
- Risk factors for death include increasing age, nonfocal infection, heart failure, dementia, and cancer 8.