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Potentiation of the antibacterial effect of methenamine by acetohydroxamic acid
Abstract:
In vitro testing shows nearly all strains of Proteus to be susceptible to methenamine. However, infection by urease-producing bacteria alkalinizes the urine in vivo and prevents generation of formaldehyde, the active metabolite, from methenamine. We have previously shown acetohydroxamic acid (AHA) to be an effective inhibitor of bacterial urease in vitro and in vivo. We now present data obtained by use of static and dynamic in vitro systems, which show that, by preventing urease-induced alkalinization of urine, AHA enables methenamine to exert its antibacterial effect against representative Proteus species.
Insights
Acetohydroxamic acid (AHA) prevents urine alkalinization caused by urease-producing bacteria. This allows methenamine to effectively combat Proteus infections by enabling formaldehyde generation.
Area of Science:
- Microbiology
- Pharmacology
- Urology
Background:
- Methenamine is effective against Proteus in vitro, but urease-producing bacteria in vivo raise urine pH, inhibiting formaldehyde generation.
- Acetohydroxamic acid (AHA) is a known inhibitor of bacterial urease, effective both in vitro and in vivo.
- Proteus infections are common and can lead to complications if not adequately treated.
Purpose of the Study:
- To evaluate the efficacy of acetohydroxamic acid (AHA) in restoring methenamine's antibacterial activity against Proteus species in a simulated urinary environment.
- To investigate the mechanism by which AHA counteracts urease-induced alkalinization and facilitates methenamine's action.
Main Methods:
- Utilized static and dynamic in vitro urinary system models.
- Assessed bacterial susceptibility to methenamine under conditions of urease activity and AHA co-administration.
- Monitored urine pH changes in response to bacterial urease and the inhibitory effect of AHA.
Main Results:
- AHA effectively prevented urease-induced alkalinization of urine in both static and dynamic in vitro systems.
- In the presence of AHA, methenamine demonstrated significant antibacterial activity against representative Proteus species, which was previously inhibited by high urine pH.
- The results confirm that maintaining acidic urine pH is crucial for methenamine's efficacy.
Conclusions:
- Acetohydroxamic acid (AHA) can restore the in vivo efficacy of methenamine against Proteus by inhibiting bacterial urease and preventing urine alkalinization.
- This combination therapy presents a promising strategy for managing urinary tract infections caused by urease-producing bacteria.
- Further clinical studies are warranted to confirm the therapeutic potential of AHA and methenamine co-administration.