[Carbapenem resistance in Pseudomonas aeruginosa isolated from urine cultures: prevalence and risk factors]

OBJECTIVE

Pseudomonas aeruginosa is a non-fermentative gram-negative bacillus with a great ability to develop resistance to multiple antibiotics, including carbapenems, which is a growing problem worldwide. The aim of this study was to analyse the prevalence of carbapenem-resistant P. aeruginosa (CRPA) in urine cultures and to determine the risk factors associated with the development of carbapanem resistance.

METHODS

Positive urine cultures to P. aeruginosa between September 2012 and September 2014 were identified. We excluded repetitive cultures from the same patient. We created a database with different variables, including antimicrobial resistance. The prevalence of carbapenem resistance and the risk factors for growth of CRPA were analysed.

RESULTS

Ninety-one patients with positive urine cultures to P. aeruginosa were included. The prevalence of CRPA was 22%. The risk factors to CRPA infection in the univariate analysis were: congestive heart failure (p=0.02), previous treatment with ampicillin (p=0.04), meropenem (p=0.04), piperacillin-tazobactam (p=0.01), trimethoprim-sulfamethoxazole (p= 0.01) and previous treatment with more than one antibiotic (p<0.01). Only congestive heart failure (p<0.01) and previous treatment with more than one antibiotic (p<0.01) showed statistically significant differences in the multivariate analysis.

CONCLUSIONS

The prevalence of CRPA in urine cultures is high in our population. We should assess the presence of risk factors as previous treatment with more than one antibiotic or comorbidities such as heart failure, in order to select an appropriate empirical treatment in patients with severe urinary tract infections.

Remission of HIV-associated myelopathy after highly active antiretroviral therapy

HIV-associated myelopathy is the leading cause of spinal cord disease in HIV-infected patients. Typically, it affects individuals with low CD4 T cell counts, presenting with slowly progressive spastic paraparesis associated with dorsal column sensory loss as well as urinary disturbances. Other aetiologies must be first ruled out before establishing the diagnosis. We report here the case of a 37-year-old woman with advanced HIV disease, who developed HIV-associated myelopathy. The patient showed a gradual improvement after beginning with highly active antiretroviral therapy and, finally, she achieved a complete functional recovery. In addition, neuroimaging and neurophysiological tests normalized.

Response to standard syphilis treatment in patients infected with the human immunodeficiency virus

In a study designed to evaluate the efficacy of penicillin in HIV-infected patients with syphilis and to determine the clinical and laboratory responses after treatment, 13 patients with HIV infection and syphilis were assessed at enrollment and at the last follow-up examination (median time of 21 months). The Venereal Diseases Research Laboratory (VDRL) test, the Treponema pallidum hemaglutination test, and leukocyte counts in cerebrospinal fluid were evaluated both at enrollment and at the last follow-up visit, and the polymerase chain reaction for Treponema pallidum DNA and the rabbit infectivity test were performed on cerebrospinal fluid samples at the last follow-up visit. Primary syphilis was confirmed in four patients, latent syphilis in five, and neurosyphilis in four. After penicillin treatment, all patients were asymptomatic. The serum rapid plasma reagin test became negative in five patients, and titers declined in eight. The VDRL test, Treponema pallidum DNA, and the rabbit infectivity test were negative in all 13 patients. Except for one patient whose serological titer was slow to decline, all patients had good clinical and serological responses to penicillin. In certain settings, factors other than penicillin treatment failure should be considered in HIV-infected patients with suspected relapse of syphilis.

Spontaneous non-typhoidal Salmonella peritonitis in patients with serious underlying disorders

Non-typhoidal Salmonella is a rare cause of spontaneous bacterial peritonitis (SBP). Non-typhoidal Salmonella SBP has been reported in patients with relatively normal ascitic fluid protein levels. Five patients with non-typhoidal Salmonella SBP and a review of the literature are reported. These patients had chronic underlying disorders, such as malignancy, or other conditions causing immunosuppression. In previous reports, an ascitic fluid protein level above 1.5 g/dl was present in six patients, and under 1.5 g/dl in two. In the present report, ascitic fluid protein is above 2.5 g/dl in three patients and under 1.5 g/dl in one. Immunosuppression and the virulence of the organism seem to play a major role in non-typhoidal Salmonella SBP. Physicians should be alert to the possibility of non-typhoidal Salmonella infection in patients with SBP and normal protein levels in ascitic fluid.

Parkinsonism in an HIV-infected patient with hypodense cerebral lesion

A 49-year-old man presented with fever and parkinsonism. Examination of cerebrospinal fluid confirmed tuberculous meningitis. Cerebral computerized tomography scan revealed hypodense lesions and human immunodeficiency virus tests were positive. The patient's clinical picture and parkinsonism were improved with tuberculosis treatment.

Neurosyphilis in HIV-infected patients

To determine the prevalence and the clinical and serological findings of neurosyphilis in HIV-infected patients, Treponema pallidum hemagglutination (TPHA) tests, CD4+ lymphocyte counts and determination of rapid plasma reagin (RPR) titers were performed in 972 HIV-infected patients over a period of 3.5 years. Patients were scored according to the Centers for Disease Control's classification for HIV infection. Reactive serum syphilis tests and positive cerebrospinal fluid (CSF)-Venereal Disease Research Laboratory (VDRL) tests, with or without clinical symptoms, were used as the criteria for diagnosis of neurosyphilis. The TPHA test was positive in 31 patients, representing 3.1% of all HIV-infected patients included in the study. Of these, 13 were intravenous drug addicts, 14 were homosexuals and 4 were heterosexuals. Diagnosis of syphilis was concurrent with HIV infection in 19 patients, prior to HIV infection in 6 patients and after HIV infection in 6 patients. CSF examinations were performed in 28 of the 31 (90.3%) patients with serologically evident syphilis. Four patients had positive CSF-VDRL tests with pleocytosis (23.5% of untreated syphilis patients in whom CSF was examined), three of whom reported mild headache, which was considered a doubtful manifestation of neurosyphilis. Patients with syphilis diagnosed and treated prior to diagnosis of HIV infection did not have evidence of neurosyphilis. Seven patients had pleocytosis with a negative CSF-VDRL test, without any clinical manifestations of neurosyphilis. There was no significant difference in the mean CD4+ lymphocyte count between patients with and without neurosyphilis (p = 0.5). RPR titers in neurosyphilis patients were greater than those in patients previously treated for syphilis and in those with pleocytosis only (p = 0.046 and 0.036, respectively). All neurosyphilis patients had an RPR titer > 1:8. After therapy, neurosyphilis patients had negative CSF-VDRL tests with a lower level of pleocytosis. The prevalence of neurosyphilis was 0.4% in HIV-infected patients and 23.5% in HIV-infected patients with untreated syphilis. This high prevalence of neurosyphilis warrants CSF examination in HIV-infected patients with syphilis, regardless of the stage of syphilis.

Cerebral tuberculoma--a comparative study in patients with and without HIV infection

The microbiological, clinical and radiological findings of cerebral tuberculomas in four patients with and in five patients without HIV infection were compared. The study was carried out during the last 14 years. The CT scans were analyzed in a blinded fashion. Cerebral tuberculoma in HIV-negative patients was clinically characterized by seizures, while in HIV-positive patients this finding was absent. All four HIV-infected patients had headache and fever and their CSF showed lymphocytic meningitis. Two HIV-negative and three HIV-positive patients had concurrent extracerebral tuberculosis. In HIV-infected patients, the cerebral tuberculoma was a secondary finding of disseminated tuberculosis. In our small patient samples, the cerebral tuberculoma presented as spontaneous hypodense cerebral lesions in all the HIV-positive patients but as a hyperdense cerebral lesion in the HIV-negative patients. Two patients of each group had ring enhancement lesions. Cerebral tuberculoma was diagnosed in about 4 weeks for HIV-positive patients, but took some 16 weeks for HIV-negative patients, the latter being first suspected of having a cerebral tumor or bacterial abscess. Diagnostic craniotomy was thus necessary for the HIV-negative patients. One patient of each group died as a consequence of cerebral tuberculoma, all the remaining patients improved with treatment.