Proteus mirabilis resistant to carbapenems isolated from a patient with a venous leg ulcer: a case report

OBJECTIVE

The aim of the study was to phenotypically investigate the expression of the enzyme Klebsiella pneumoniae carbapenemase (KPC) in a Proteus mirabilis sample resistant to carbapenems, isolated from the wound of a patient with a venous leg ulcer (VLU) treated at an outpatient referral service.

METHOD

This was a case study conducted with a patient who had a VLU on the lower left limb. Samples were taken for the examination of microbiological material from the patient's wound, using an aseptic technique. The colonies extracted were submitted to Gram staining and biochemical tests to identify the strain. In addition, an antimicrobial susceptibility test, E-test and a modified Hodge test were performed.

RESULTS

The identified microorganism was Proteus mirabilis, which showed resistance to cefuroxime and the carbapenems imipenem and meropenem. As well as the minimum inhibitory concentration (MIC) of 3.0μg/ml for imipenem, demonstrating resistance, there was no KPC production by the tested isolate, which presented a negative modified Hodge test.

CONCLUSION

The results highlight the importance of microbiological surveillance, aimed at reducing morbidity and mortality rates associated with infection by multiresistant bacteria.

Genetic variability in the ITS and IGS regions of the ribosomal DNA of Acremonium cavaraeanum exhibiting antimicrobial activity

Endophytic microorganisms represent promising alternatives for obtaining new drugs of biotechnological importance. In this study, the endophytic species Acremonium cavaraeanum (A1a) isolated from Cocos nucifera was cultivated for the production of secondary metabolites, and its extracts and fractions were evaluated by the dilution method (MIC). The EtOAc extracts and MeOH fractions were tested against Gram-positive and -negative bacteria, and had an MIC of 125 µg/mL when evaluated in the EtOAc extract (EBI). The EtOAc extract (EBII) had an MIC of 62.25 µg/mL for Staphylococcus aureus and an MIC between 125 and 250 µg/mL for Gram-negative bacteria. The methanolic fractions showed activity with MIC between 125 and 250 µg/mL for all bacteria tested. The IGS region of the rDNA repeat unit of genomic DNA was analyzed by PCR/RFLPs, including endonucleases PstI, BamHII, HinfI, and EcoRI. The physical maps showed different restriction sites for the 6 Acremonium sp isolates, and revealed 5 RFLP patterns. The results showed that isolates of the same Acremonium species exhibited variation in this specific region. The sequences of ITS1-5.8S-ITS2 regions were aligned by Clustal W using the neighbor joining method, which grouped the isolates into 5 distinct clusters. This study aimed to evaluate the genetic diversity of A. cavaraeanum crops exhibiting antibacterial activity. The results of this study indicate that different fungal genetic isolates have biotechnological potential for the production of active bio-compounds against several human pathogens.