Phenotypic, molecular and antimicrobial susceptibility assessment in isolates from chronic ulcers of cured leprosy patients: a case study in Southern Brazil

Abstract

BACKGROUND One of the most stigmatizing physical sequelaeof leprosy in cured patients is the development of chronic lower extremity ulcers. The bacterial diversity present in ulcers is considered one of the factors that can delay the healing process, as well as serve as a focus for severe secondary infections. OBJECTIVE To identify the microbiota and antimicrobial resistance profile of bacteria isolated from skin ulcers in patients cured of leprosy. METHODSAfter obtaining informed consent, material was collected from ulcers of 16 patients treated at the Outpatient Public Health Dermatology Clinic of Rio Grande do Sul and Hospital Colônia Itapuã. Sampleswere collected during dressing, and the material sent to the Microbiology Laboratory of the Federal University of Health Sciences of Porto Alegre for microbiological culture. Methicillin-resistant Staphylococcus aureus (MRSA) was characterized by two molecular methods, including detection of the mecA gene by PCR and SCCmecgene typing. RESULTS Cultures revealed microorganisms in all ulcers: Gram-negative bacilli in 80%, Gram-positive cocci in 63%, and mixed microflora in 36%. Staphylococcus aureus and Pseudomonas aeruginosa were the most prevalent bacteria. Assessment of the antimicrobial resistance profile was notable for the presence of MRSA. Molecular analysis of this isolate revealed presence of the mecA gene contained in a type IV staphylococcal cassette chromosome mec (SCCmec). CONCLUSIONS In patients with leprosy, laboratory culture of skin ulcers is essential for correct antibiotic selection and to control emerging pathogens, such as MRSA carrying SCCmec type IV.

Virulence and resistance features of Pseudomonas aeruginosa strains isolated from chronic leg ulcers

“…On the other hand, international data demonstrate variable resistance: one study revealed strains isolated from chronic wounds resistant to piperacillin/tazobactam and aztreonam [ 18 ], another study found P. aeruginosa strains 100 % susceptible only to imipenem and meropenem, followed by ceftazidime (86 %) and amikacin, aztreonam, cefepime, ciprofloxacin, and piperacillin tazobactam (57 % each) [ 19 ]; opposite, another study found only 11.5 % resistance to imipenem (out of a collection of 512 P. aeruginosa strains), 66 % of the strains resistant to streptomycin, and 25.2 % and 28.5 % respectively were resistant to aminoglycoside antibiotics ciprofloxacin and gentamicin, respectively, polymyxin B having the greatest antibacterial activity (4.9 % resistant strains to this antibiotic) [ 20 ].…”

Chronic ulcers: considerations about contaminant flora, infection and antimicrobial treatment

“…Our considerations do not discredit the results of the article of Gelatti and colleagues; 2 however, they alert to the implications of dermatological preliminary investigation in the evaluation of critical colonization and infection of chronic ulcers in basic care. Furthermore, they emphasize the fact that indication and orientation of systemic antibiotic therapy should not be based on results of exudation cultures, since adequate clinical and laboratorial correlation is required.…”

“…After careful reading of the excellent text of Gelatti et al, 2 which explored microbiological aspects of chronic ulcer exudation in individuals cured of leprosy, some questions of clinical care aspect arise that we believe deserve consideration.…”

Identification of mycobacteria isolated from the contents of trophic ulcers of leprosy patients

“…L. Gellati и соавт. [11] при изучении содержимого трофических язв у 16 больных лепрой выявили в 80% случаев рост грам-отрицательных бактерий, в 63% -грамположитель-ных кокков, в 36% -смешанной микрофлоры. Чаще всего у больных, находящихся на лечении в НИИЛ, высевались Staphylococcus aureus и Pseudomonas aeruginosa [9].…”

“…В настоящее время накоплен большой опыт по выявлению и лечению бактериальной фло-ры в трофических язвах больных лепрой [7,10,11]. Однако мы не встретили работ по микобактериаль-ной идентификации содержимого трофических язв.…”