Ivani Lúcia Leme

Epidemiologic typing of multiply drug-resistant Pseudomonas aeruginosa isolated from an outbreak in an intensive care unit

From June to August 1991, there was an outbreak of Pseudomonas aeruginosa infections in an intensive care unit in a general hospital in Sao Paulo, Brazil. We obtained 14 isolates from 14 patients, 11 from tracheal aspirate, and 3 from surgical wound exudates. These strains were typed by serotyping, pyocin typing, and pulsed-field electrophoresis (CHEF) of chromosomal DNA (chrDNA), and the different typing methods were analyzed. These three methods demonstrated seven identical strains. We also performed an extensive antibiogram (33 drugs) in all 14 isolates. The incidence of resistance to aminoglycosides, extended-spectrum beta-lactams, and quinolones was very high among the seven identical isolates; however, the antibiogram profile differed significantly among the isolates. Our results suggest that a unique strain caused several cross-transmitted infections during this period of time, and the emergence of antimicrobial resistance has been occurring before and after the establishment of the epidemic strain by selective drug use. The chrDNA fingerprinting proved to be versatile and precise for epidemiologic investigations of P. aeruginosa infections.

Oxacillin- and quinolone-resistant Staphylococcus aureus in Sao Paulo, Brazil: a multicenter molecular epidemiology study.

OBJECTIVE To investigate the possibility of interhospital spread of multiresistant Staphylococcus aureus in Sao Paulo, Brazil. DESIGN We evaluated 13 nosocomial S aureus strains selected because of resistance to oxacillin and ciprofloxacin. SETTING The strains were collected between March 1991 and September 1991 from four different hospitals in Sao Paulo. Two were teaching hospitals, and two were private hospitals. PATIENTS Each strain was isolated from a different patient. All patients were hospitalized when the strains were isolated. INTERVENTIONS The strains were typed by restriction endonuclease analyses of plasmid DNA (REAP) using EcoRI, HindIII, RsaI, and AluI and by extended antibiogram profile (34 drugs). RESULTS All strains had identical plasmid and antibiogram profile. They demonstrated the same plasmid pattern as previously described in one of the hospitals studied. CONCLUSIONS Our results suggest the dissemination of a unique oxacillin- and quinolone-resistant strain of S aureus in several hospitals of Sao Paulo, Brazil.

Molecular epidemiology and antimicrobial susceptibility testing. Testing of quinolone-resistant Staphylococcus aureus strains isolated in Brazil.

An outbreak of 20 oxacillin-resistant Staphylococcus aureus (ORSA) bloodstream infections (BSIs) was detected in the intensive care unit (ICU) at Hospital Sao Paulo, Brazil. In a surveillance study, 10% of ICU personnel were defined as chronic nasal carriers of ORSA. Thirteen BSIs and five nasal isolates were available for phage typing, restriction endonuclease analysis of plasmid (REAP) and chromosomal DNA hybridized with 32P rRNA gene probe. Susceptibility testing against select antimicrobial agents, including 11 quinolones, six glycopeptides, and five topical agents, was performed by broth microdilution and the disk diffusion tests. Ten of the 13 BSI isolates and four of the five nasal strains were oxacillin and quinolone resistant. The new fluoroquinolones CI-960 and WIN57273, the glycopeptides, and the topical agents ramoplanin, bacitracin, mupirocin, and novobiocin were most active. Fourteen strains, 12 BSI isolates, and three nasal isolates showed the same REAP profile. Moreover, the same REAP and chromosomal profile was detected in at least nine BSI isolates and in two nasal isolates. These strains were nontypable by phage typing. We concluded that nosocomial cross-transmission of a single, multiresistant strain of S. aureus occurred and that the epidemic reservoir was nasal carriage by ICU personnel.

Glycopeptides susceptibility among enterococci isolated from a poultry farm in São Paulo, Brazil (1996/1997)

Para avaliar a resistencia de enterococos de origem animal aos antibioticos glicopeptideos foi projetado um estudo em aves comerciais que usavam racoes suplementadas com avoparcina como promotor de crescimento. A suscetibilidade aos glicopeptideos avoparcina, teicoplanina e vancomicina foi determinada em 217 enterococos isolados de fezes de frango colhidas atraves de swab cloacal (uma amostra/ave). Nos tres grupos Teste foram usadas fezes de frangos em diferentes fases de crescimento, com 14, 21 e 35 dias de idade. As aves foram alimentadas com racao contendo avoparcina (10 mg/kg de racao) desde o primeiro dia de vida. Como controle foram usadas fezes de frangos do bioterio da Faculdade de Medicina Veterinaria da Universidade de Sao Paulo, onde nunca foram usados glicopeptideos nas racoes das aves ou no local. Nenhum enterococo resistente a vancomicina (ERV) foi isolado nas amostras examinadas, porem, foi detectado um aumento de Enterococcus faecium na microbiota fecal de frangos que utilizavam avoparcina na racao, independente da idade da ave.

Padrão de sensibilidade de 117 amostras clínicas de Staphylococcus aureus isoladas em 12 hospitais

OBJETIVO. Avaliar o padrao de sensibilidade in vitro de amostras clinicas de Staphylococcus aureus sensiveis (OSSA) e resistentes a oxacilina (ORSA) a outros antimicrobianos que podem ser utilizados no tratamento de infeccoes estafilococicas. MATERIAL E METODO. Foram analisadas 117 amostras clinicas de S. aureus isoladas em varios hospitais de Sao Paulo. Tambem foram incluidas amostras isoladas em Campinas, SP, e Joao Pessoa, PB. A avaliacao da sensibilidade in vitro aos antimicrobianos foi realizada pela tecnica de microdiluicao em caldo, utilizando os procedimentos preconizados pelo National Committee for Clinical Laboratory Standards (NCCLS). Foi avaliada a concentracao inibitoria minima (MIC) para 24 antimicrobianos da classe dos b-lactâmicos, fluoroquinolonas, aminoglicosideos, glicopeptideos, macrolideos, lincosaminas e estreptograminas. Foram avaliadas tanto drogas disponiveis comercialmente quanto as que ainda se encontram em fase de pesquisa. A resistencia cruzada entre dez fluoroquinolonas foi avaliada em 24 amostras. RESULTADOS. Os glicopeptideos, o RP-59500 e a mupirocina foram os antimicrobianos que apresentaram maior atividade in vitro contra amostras de ORSA (100% sensibilidade). Oitenta e sete por cento das amostras de OSSA foram sensiveis a ciprofloxacina (MIC50 0,25mg/mL), enquanto que, para os ORSA, a sensibilidade foi de apenas 38% (MIC50 >4mg/mL). A resistencia cruzada para as fluoroquinolonas foi observada mesmo para drogas nao disponiveis comercialmente. As fluoroquinolonas que permaneceram ativas contra amostras resistentes a ciprofloxacina (clinafloxacina e WIN-57.273) apresentaram MICs 8 a 64 vezes mais elevados que as amostras sensiveis a ciprofloxacina, sugerindo que, quando lancadas na pratica clinica, esses MICs possam se elevar ainda mais, inviabilizando o uso clinico desses compostos. CONCLUSAO. Os resultados do presente estudo mostraram uma alta taxa de resistencia a antimicrobianos das amostras de S. aureus nos hospitais do Brasil, restando poucas opcoes para o tratamento de infeccoes causadas por ORSA.OBJECTIVE To evaluate the antimicrobial susceptibility pattern of oxacillin susceptible (OSSA) and resistant Staphylococcus aureus (ORSA) isolates to other antimicrobial agents that can be used for the treatment of staphylococcal infections. MATERIAL AND METHOD We evaluated 117 clinical S. aureus isolates from several São Paulo hospitals. Clinical isolates from Campinas, SP and from João Pessoa, PB, were also included. The in vitro susceptibility testing was performed by broth microdilution as described by the National Committee for Clinical Laboratory Standards (NCCLS). The minimum inhibitory concentration (MIC) was evaluated for 24 antimicrobial agents, including beta-lactams, fluoroquinolones, aminoglycosides, glycopeptides, macrolides, lincosamides and streptogramins. Both commercially available and experimental drugs were included in the study. Cross-resistance among fluoroquinolones was evaluated by susceptibility testing 24 isolates to 10 fluoroquinolones. RESULTS The antimicrobial agents that showed the highest in vitro activity were the glycopeptides, the streptogramin RP-59.500, and the mupirocin (100% susceptibility). Eighty-seven percent of the OSSA and only 38% of the ORSA isolates were susceptible to ciprofloxacin (MIC50 0.25 microgram/mL and > 4 micrograms/mL, respectively). Cross-resistance among fluoroquinolones were noted even for the experimental drugs. Two fluoroquinolones remained active against ciprofloxacin-resistant isolates, clinafloxacin and WIN-57.273. However, the ciprofloxacin-resistant isolates had MICs eight-to 64-fold higher than the ciprofloxacin-susceptible isolates, suggesting that the MICs may continue to increase when these fluoroquinolones become commercially available. CONCLUSION Our results showed a high rate of antimicrobial resistance among S. aureus from the Brazilian hospitals. Very few drugs can still be used for the treatment of staphylococcal infections.

Application of restriction endonuclease analysis of chromosomal DNA in the study of Staphylococcus aureus colonization in continuous ambulatory peritoneal dialysis patients.

The relationship between nasal and skin colonization with Staphylococcus aureus and subsequent infection in continuous ambulatory peritoneal dialysis (CAPD) patients in Brazil has been documented by restriction endonuclease analysis of plasmid DNA. However, S. aureus strains without detectable plasmids have been identified. Using restriction endonuclease analysis of chromosomal DNA hybridized with an rRNA gene probe, we document the diversity of S. aureus strains without detectable plasmids colonizing CAPD patients. Ten paired strains without detectable plasmids from five patients were studied by restriction endonuclease analysis of chromosomal DNA and by phage typing. Five different profiles were obtained by restriction endonuclease analysis of chromosomal DNA. Although four of the ten paired isolates were nontypeable by phage typing, all were discriminated by restriction endonuclease analysis of chromosomal DNA. These results demonstrate that restriction endonuclease analysis of chromosomal DNA is a useful epidemiologic tool and complements the restriction endonuclease analysis of plasmid DNA of S. aureus by providing a means of typing strains without detectable plasmids.

Identification of Lactobacillus spp. from broiler litter in Brazil

Lactobacillus spp. were identified in 100 broiler litter samples collected from different poultry-rearing regions in Brazil. Ten different Lactobacillus species were identified: L. plantarum, L.casei subsp. pesudoplantarum, L. delbrueckii subsp. delbrueckii, L. reuteri, L. murinus, L. agilis, L. delbrueckii subsp. lactis, L. salivarus subsp. salicinus, L. viridenscens and L. amylophilus.