Pressure ulcer as a reservoir of multiresistant Gram-negative bacilli: risk factors for colonization and development of bacteremia

Abstract The purpose of this study was to identify the risk factors that predispose patients who are hospitalized with pressure ulcers (PUs) colonized by Gram-negative bacilli (GNB) to develop bacteremia. In addition, we also detected main phenotypes of resistance in infected and uninfected PUs. A prospective cohort study was conducted at the Clinical Hospital of the Federal University of Uberlândia including patients with Stage II or greater PUs, colonized or not with GNB, from August 2009 to July 2010. Infected ulcers were defined based on clinical signs and on positive evaluation of smears of wound material translated by a ratio of polymorphonuclear cells to epithelial cells ≥2:1, after Giemsa staining. A total of 60 patients with Stage II PUs were included. Of these 83.3% had PUs colonized and/or infected. The frequency of polymicrobial colonization was 74%. Enterobacteriaceae and GNB non-fermenting bacteria were the most frequent isolates of PUs with 44.0% of multiresistant isolates. Among patients who had infected PUs, six developed bacteremia by the same microorganism with a 100% mortality rate. In addition, PUs in hospitalized patients were major reservoir of multiresistant GNB, also a high-risk population for the development of bacteremia with high mortality rates.

Spread of multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa clones in patients with ventilator-associated pneumonia in an adult intensive care unit at a university hospital

Background:In Brazil, ventilator-associated pneumonia (VAP) caused by carbapenem resis- tant Acinetobacter baumanniiand Pseudomonas aeruginosaisolates are associated with significant mortality, morbidity and costs. Studies on the clonal relatedness of these isolates could lay the foundation for effective infection prevention and control programs.Objectives: We sought to study the epidemiological and molecular characteristics of A. baumannii vs. P. aeruginosaVAP in an adult intensive care unit (ICU).Methods: It was conducted a cohort study of patients with VAP caused by carbapenem resistant A. baumanniiand P'. aeruginosaduring 14 months in an adult ICU. Genomic studies were used to investigate the clonal relatedness of carbapenem resistant OXA-23-producing A. baumanniiand P. aeruginosaclinical isolates. The risk factors for acquisition of VAP were also evaluated. Clinical isolates were collected for analysis as were samples from the environment and were typed using pulsed field gel electrophoresis.Results: Multivariate logistic regression analysis identified trauma diagnosed at admission and inappropriate antimicrobial therapy as independent variables associated with the development of A. baumanniiVAP and hemodialysis as independent variable associated with P. aeruginosaVAP. All carbapenem resistant clinical and environmental isolates of A. baumanniiwere OXA-23 producers. No MBL-producer P. aeruginosawas detected. Molecular typing revealed a polyclonal pattern; however, clone A (clinical) and H (surface) were the most frequent among isolates of A. baumanniitested, with a greater pattern of resistance than other isolates. In P. aeruginosathe most frequent clone I was multi-sensitive.Conclusion: These findings suggest the requirement of constant monitoring of these microor- ganisms in order to control the spread of these clones in the hospital environment.

Genotypic study documents divergence in the pathogenesis of bloodstream infection related central venous catheters in neonates

OBJECTIVE: To investigate the pathogenesis of bloodstream infection by Staphylococcus epidermidis, using the molecular epidemiology, in high-risk neonates. METHODS: We conducted a prospective study of a cohort of neonates with bloodstream infection using central venous catheters for more than 24 h. "National Healthcare Safety Network" surveillance was conducted. Genotyping was performed by DNA fingerprinting and mecA genes and icaAD were detected by multiplex-PCR. RESULTS: From April 2006 to April 2008, the incidence of bloodstream infection and central venous catheter-associated bloodstream infection was 15.1 and 13.0/1000 catheter days, respectively, with S. epidermidis accounting for 42.9% of episodes. Molecular analysis was used to document the similarity among six isolates of bloodstream infection by S. epidermidis from cases with positive blood and central venous catheter tip cultures. Fifty percent of neonates had bloodstream infection not identified as definite or probable central venous catheter-related bloodstream infection. Only one case was considered as definite central venous catheter-related bloodstream infection and was extraluminally acquired; the remaining were considered probable central venous catheter-related bloodstream infections, with one probable extraluminally and another probable intraluminally acquired bloodstream infection. Additionally, among mecA+ and icaAD+ samples, one clone (A) was predominant (80%). A polyclonal profile was found among sensitive samples that were not carriers of the icaAD gene. CONCLUSIONS: The majority of infections caused by S. epidermidis in neonates had an unknown origin, although 33.3% appeared to have been acquired intraluminally and extraluminally. We observed a polyclonal profile between sensitive samples and a prevalent clone (A) between resistant samples. .

Methicillin/Oxacillin-resistant Staphylococcus aureus as a hospital and public health threat in Brazil

Methicillin-resistant Staphylococcus aureus is an established nosocomial pathogen (HA-MRSA, hospital acquired MRSA), but has recently begun to appear in the community (CA-MRSA, community acquired MRSA). The cause of resistance to methicillin and all other â-lactam antibiotics is the mecA gene, which is situated on a mobile genetic element, the Staphylococcal Cassette Chromosome mec (SCCmec). Seven major variants of SCCmec, type I to VII are distinguished. HA-MRSA disseminated worldwide and causes the majority of S. aureus nosocomial infections with a limited number of clones disseminated including the Brazilian Epidemic Clone (BEC, ST239-MRSA-III). CA-MRSA isolates are susceptible to non-â-lactam antibiotics, usually isolated from healthy individuals which do not possess any unknown risk factors for MRSA infection and are associated with a larger clonal diversity compared with HA-MRSA. However, during recent years distinction between HA-MRSA and CA-MRSA is beginning to fade. Actually, knowledge about MRSA disseminating clones is required to implement any strategies to control the transmission of MRSA either within hospitals or in community. For this reason, rapid identification of strains is an important issue. The rate of HA-MRSA can be reduced substantially through the implementation of interventions strategies, even in settings where MRSA is endemic as in most Brazilian hospitals. However, these policies could be quite complicated in the light of an increasing CA-MRSA prevalence in healthcare facilities, considering that distinction between HA-MRSA and CA-MRSA has started to disappear.

Fatores de risco para colonização e sepse por Candida albicanse Candida não albicans em neonatos críticos / Risk factors for colonization and sepsis by Candida albicans and non-albicans Candida in critical newborns

O objetivo do estudo foi avaliar as taxas de sepse e de colonização por Candida albicans e Candida não albicans e os fatores de risco relacionados em neonatos críticos. O estudo foi realizado na Unidade de Terapia Intensiva Neonatal (UTIN) do Hospital de Clínicas da Universidade Federal de Uberlândia, com 10 leitos, através de dois tipos de vigilância epidemiológica: “National Nosocomial Infections Surveillance”(NNIS) e laboratorial, no período de Jan/02 a Dez/07. As amostras de Candida isoladas de infecção foram obtidas no Laboratório de Microbiologia do hospital. Os neonatos foram avaliados quanto à colonização nas mucosas oral e intestinal, após 24 horas da internação na unidade e em intervalos semanais até a alta, utilizando-se “swab” estéril, cultivado em “Cromo-agar”. No total, a taxa de sepse foi 13,6%, sendo que as candidemias responderam por 6% das mesmas, todas de natureza hospitalar, associadas com uma letalidade de 33,3%. A taxa de infecção por Candida/ 1.000 pacientes dia foi de 0,96, sendo a maioria (47,4%; 9/19) por Candida albicans. Foram constatados 19 (54,28%) neonatos colonizados, dos quais originaram 35 amostras, 15 de mucosa bucal com 53,3% por Candida albicans e 46,7% Candida não albicans, e 20 de mucosa perianal com 50,0% por Candida albicans. Os fatores de risco associados com a candidemia invasiva (P d” 0,05) foram: uso de CVC e de antibióticos, e para colonização por Candida foram: nutrição parenteral, entubação e uso prévio de antibiótico com um predomínio de cefalosporina de terceira geração (83,3%). Não foi observada relação entre colonização prévia e candidemia invasiva, com o de apenas uma criança com sepse por Candida albicans, colonizada previamente.

The objective of this study was to evaluate the rates of sepsis and colonization by Candida albicans andnon- albicans Candida and the risk factors observed in critical newborns. The study was carried out in a 10-bed Neonatal Intensive Care Unit (NICUs) of the Clinical Hospital of the Federal University of Uberlândia, through two types of epidemiological surveillance: “National Nosocomial Infections Surveillance" (NNIS) and laboratorial in the period of Jan/02 to Dec/07. Samples of Candida isolated from infection were obtained in the Laboratory of Microbiology of the hospital. The newborns were evaluated according to oral and intestinal colonization, after 24 hours of hospitalization in that unit in weekly intervals until discharge. Overall, the rate of sepsis was 13.6%, and the candidemias accounted for 6%, from hospital nature , associated with 33.3% of lethality. The rate of infection by Candida/1,000 patient daily was 0.96, while the majority (47.4%; 9/19) by Candida albicans. Nineteen (54.28%) neonates colonized were observed from them 35 samples were provided, 15 of oral mucosa with 53.3% by Candida albicans, and 46.7% by non-albicans Candida, and 20 of mucous perianal with 50.0% by Candida albicans. The risk factors associated with invasive candidemia (P d” 0.05) were: use of CVC and antibiotics, and colonization by Candida were: parenteral nutrition, intubation and previous use of antibiotic with a predominance of the third generation cephalosporin ( 83.3%). There was no relationship between prior colonization and invasive candidemia, with only one child with sepsis by Candida albicans, previously colonized.

Two outbreaks of mixed etiology associated with central venous catheters inserted by phlebotomy in critical neonates

Staphylococcus aureus and coagulase-negative staphylococci are the main cause of sepsis in Neonatal Intensive Care Unit (NICU). Central venous catheters (CVCs) are an important part of critical neonates' treatment and are associated with sepsis. The aim of this study was to investigate two outbreaks caused by Staphylococcus aureus and Staphylococcus epidermidis associated with CVC inserted by phlebotomy in critical neonates. The surveillance was performed from January 2001 to December 2005 at the Brazilian NICU. The genotypic analysis of oxacillin susceptible S. aureus (OSSA) and oxacillin resistant S. epidermidis (ORSE) was performed based on pulsed-field gel electrophoresis (PFGE). Staphylococcus was the most frequent pathogen (65.8 percent) with highest incidence of CoNS (59.9 percent) followed by S. aureus (40.1 percent). During the five years of surveillance, there were two outbreaks detected, occurred in January-February/02 and August/02 and confirmed by PFGE analysis. The predisposing factors for infection corresponding to both outbreaks were: age <7 days, hospitalization > 7 days, and use of polyethylene CVC through dissection of vein (phlebotomy). This is the first relate of staphylococcal outbreaks associated with CVC inserted by phlebotomy in NICU. PFGE showed polyclonal spread of OSSA during both epidemic and endemic period, and two monoclonal outbreaks of ORSE in the same epidemic period of OSSA.

Epidemiologically relevant antimicrobial resistance phenotypes in pathogens isolated from critically ill patients in a Brazilian Universitary Hospital / Fenótipos de resistência antimicrobiana epidemiologicamente importantes de patógenos isolados de pacientes críticos de um hospital universitário brasileiro

Antimicrobial resistance is a threat to public health worldwide and is associated with higher mortality and morbidity. Despite the extensive knowledge about this problem, drug resistance has continued to emerge, especially in intensive care units (ICUs). The objective of this study was to evaluate the frequencies of epidemiologically relevant resistance phenotypes in pathogens isolated from ventilator-associated pneumonia (VAP), bloodstream infections (BSI) and urinary tract infections (UTI) in patients admitted in the adult intensive care unit (AICU) of the Clinical Hospital of Federal University of Uberlândia, during an one year period. Additionally, at the period of the study, the antibiotic consumption in AICU was verified. Coagulase-negative staphylococci and S. aureus were the main agents of BSI (43.9 percent), with 60.0 percent of oxacilin-resistance for both microorganisms, Klebsiella-Enterobacter group predominated in UTI (23.4 percent), with resistance to third generation cephalosporins in 58.0 percent of the isolates; and, Pseudomonas aeruginosa in VAP (42.0 percent), with 72.0 percent of resistance to imipenem. Cephalosporins (49.6 percent), vancomycin (37.4 percent) and carbapenems (26.6 percent) were the most prescribed antibiotics in the unit. The comparison of the results with a publication of the NNIS program evidenced a worse situation in the studied hospital, mainly between Gram-negative, that had surpassed the percentile 90 percent elaborated by that system. Based on these results a reconsideration on the empirical use of antibiotics and on prevention and control of nosocomial infections practices is recommended.

A resistência aos antimicrobianos é uma ameaça a saúde pública mundial e está associada a uma maior mortalidade e morbidade. Apesar dos vastos conhecimentos sobre este problema, a resistência aos antibióticos continua a emergir, especialmente em unidades de terapia intensiva (UTI). O objetivo deste estudo foi avaliar a freqüência de fenótipos de resistência epidemiologicamente importantes em patógenos isolados de pneumonia associada à ventilação mecânica (PAV), infecções de corrente sangüínea (ICS) e de infecções de trato urinário (UTI) nos pacientes atendidos na unidade de terapia intensiva de adultos (UTIA) do Hospital de Clínicas da Universidade Federal de Uberlândia, durante o período de um ano. Adicionalmente, no período do estudo, foi analisado o consumo de antibióticos na UTIA. Staphylococcus spp coagulase negativo e S. aureus foram os principais agentes de ICS (43,9 por cento), com 60,0 por cento de resistência à oxacilina em ambos os microrganismos. O grupo Klebsiella-Enterobacter predominou nas ITU (23,4 por cento), com resistência às cefalosporinas de terceira geração em 58,0 por cento dos isolados; e, Pseudomonas aeruginosa nas PAV (42,0 por cento), com 72,0 por cento de resistência ao imipenem. As cefalosporinas (49,6 por cento), vancomicina (37,4 por cento) e os carbapenêmicos (26,6 por cento) foram os antibióticos mais prescritos na unidade. A comparação dos resultados com publicações do programa NNIS evidenciou uma pior situação no hospital estudado, especialmente entre os Gram-negativos, que ultrapassaram o percentil 90 por cento elaborado por este programa. De acordo com os resultados apresentados neste estudo, uma revisão do uso empírico de antibióticos e da prevenção e controle de infecções hospitalares é recomendada.

Risk factors and evolution of Ventilator-associated pneumonia by Staphylococcus aureus sensitive or resistant to oxacillin in patients at the intensive care unit of a Brazilian University Hospital

This study investigated the participation and risk factors of VAP by resistant (ORSA) or sensitive (OSSA) S. aureus to oxacillin and evaluated the implications of adequate or inadequate empirical antimicrobial therapeutics in its evolution in patients interned in a mixing ICU of adults. A patient control-case study with PAVs by ORSA and OSSA was carried out from May 2005 to April 2007 involving 993 patients. VAP was defined based on clinical, radiological, and microbiological (> 106 CFU/mL count in the tracheal aspirate) criteria. Four hundred and seventy four (47.7 percent) patients were submitted to mechanical ventilation with 141 (29.7 percent) VAPs, with S. aureus as the most frequent agent (41.2 percent). The phenotype ORSA accounted for 47.5 percent and OSSA for 52.5 percent, predominant in late-onset VAPs with frequencies of 93.1 percent and 68.7 percent, respectively. Age > 60, use of corticoid and previous antibiotic therapy were related (p<0.05) with the development of VAP by ORSA. Mortality rate was higher (p>0.05) in the group with VAP by ORSA (37.9 percent). S. aureus was the main agent of VAPs, around half by ORSA, associated with age, late-onset VAP development and previous use of antibiotics and corticoids, but with no significant difference in mortality compared with VAP by OSSA.

Vancomycin-resistant van a phenotype Enterococcus faecalis: first case in Minas Gerais state and epidemiological considerations

We report the first case of vancomycin-resistant Enterococcus faecalis with VanA phenotype and vanA genotype isolated from a surgical patient in a general Hospital in Uberlândia, state of Minas Gerais, Brazil.

Formação de biofilme em amostras de Staphylococcus epidermidis isoladas de sepse relacionada a cateter vascular central em neonatos críticos / Biofilm production in Staphylococcus epidermidis samples isolated fromsepsis associated with central vascular catheter (CVC) in critical neonates

Esta pesquisa teve como objetivo verificar a presença de biofilme em amostras de S. epidermidis isoladas de sangue em casos de sepse relacionados ao uso de CVC em neonatos críticos. O estudo foi realizado na Unidade de Terapia Intensiva Neonatal (UTIN) do Hospital de Clínicas da Universidade Federal de Uberlândia, no período de Jan/02 a Dez/06. Adicionalmente, foi realizado inquéritos de prevalência pontual de colonização por este microrganismo, através da coleta de espécimes da narina e axila com auxílio de swabs, entre Janeiro de 2004 e Junho de 2005. A avaliação de formação de biofilme foi realizada por densidade ótica em placas de poliestireno, após coloração com safranina, utilizando espectrofotômetro (570nm). O teste de suscetibilidadeà oxacilina foi realizado pelo método de diluição de acordo com o “Clinical and Laboratory Standards Institute”.Foram analisadas 109 amostras de S. epidermidis de episódios de sepse, sendo 83 (76,1%) relacionadas ao uso de CVC. Em relação à presença de biofilme, 67/83 (80,7%) das amostras isoladas de neonatos com sepserelacionadas a CVC, apresentaram produção intensa, enquanto que entre as 26 não relacionadas ao uso de CVC apenas seis (23,1%) demonstraram produção de biofilme, assim como, 10 (12,3%) entre as associadas à colonização. Cerca de 73% das amostras foram resistentes à oxacilina (concentração inibitória mínima ³0,5mg/ml), incluindo 56 (83,6%) correspondentes a casos de infecção relacionados à CVC, seis (100%) amostras não relacionadas ao uso de CVC e em quatro (40%) de amostras de colonização. Conclui-se que a maioria das amostras de S. epidermidis isoladas de sepse relacionadas à CVC foram biofilme positivas e resistente à oxacilina

This research aimed to observe the biofilm production by Staphylococcus epidermidis isolated associated with central vascular catheter (CVC) related bacteremia in critical neonates. The study it was carried out in Neonatal Intensive Care Unit of the Hospital das Clínicas da Universidade Federal de Uberlândia, in the period of Jan/02 to Dez/06. Additionally, it was carried out inquiries of prevalence, through the specimen collection of the nostril and armpit with aid of swabs, between Jan/04 and Jun/05. The evaluation of biofilm production was by optical density in polystyrene plates, stained with safranin and measured with ELISA reader at 570nm. The oxacilin susceptibility test was carried out through to the dilution method in accordance with the “Clinical and Laboratory Standards Institute”. It was analyzed 109 S. epidermidis samples, being 83(76.1%) related to the use of CVC. In relation to the biofilm presence, 80.7% of the neonates isolated samples with sepsis related the CVC, had presented intense production, whereas of the 26 unrelated ones to the useof CVC, only six (23.1%) had demonstrated biofilm production as well as 10 (12.3%) of the samples associated to the colonization. About 73% of the samples were oxacilin resistant (minimum inhibitory concentration³0.5mg/ml) . In conclusion, the S. epidermidis samples isolated of CVC related sepsis were biofilm positive and pertaining to oxacilin resistant phenotype

Nosocomial bloodstream infections: organisms, risk factors and resistant phenotypes in the Brazilian University Hospital

Bacteremia is one of the most frequent and challenging hospital-acquired infection and it is associated with high attributable morbidity and mortality and additional use of healthcare resources. The objective of this work was to determine the frequencies of its occurrence, organisms and resistance phenotypes associated to nosocomial acquired bloodstream infections. A total number of 51 nosocomial bacteremia by Gram-negative and 99 by Gram-positive were evaluated and compared during a 15-month period. The risk factors associated with these bacteremias were analyzed and antibiotic use and surgery were associated with bacteremia by Gram-negative and > 2 invasive devices with Gram-positive. The resistance phenotypes ESBL (extended-spectrum beta-lactamases) (23.5 percent) and AmpC/others (17.6 percent) correspond to 41.2 percent with predominance of E. agglomerans among AmpC (44.4 percent) and K. pneumoniae among ESBLs (38.5 percent). Among S. aureus bacteremia, approximately 40 percent were associated to MRSA (methicillin-resistant Staphylococcus aureus).

Etiology and pathogenesis of bloodstream infections associated with the use of long-term central vascular catheter (CVC) in patients who undergone gastrointestinal surgery

CVC is the main factor of risk of bloodstream infections. This study purpose was determining both etiology and pathogenesis of these infections in 80 patients who undergone gastrointestinal surgery and who worn long lasting CVC, in the institution HC-UFU. Cultures were made in nostril, skin of the insertion site, tip and catheter hub, in addition to hemoculture in those suspects of sepsis. The colonization incidence rate of the catheter tip was 12.5/ 1,000 catheter days and the CVC associate infection rate was 3.1/1,000 catheter days. Frequencies of skin, hub and catheter tip colonization were 13.8 percent, 8.9 percent and 13.3 percent, respectively. Coagulase-negative Staphylococci were the most found microorganisms in nostril (74 percent), skin (45.4 percent) and hub (75 percent) and Gram-negative bacilli (50 percent), followed by S. aureus (25 percent) the most common ones in catheter tip. Approximately 51 percent of patients received antibiotics and most of them (53.7 percent) had therapeutic purpose. The frequency of patients with clinical sepsis was 27.5 percent. Three cases of bacteremia associated with the use of CVC were detected (3.8 percent), with S. aureus in two of them and K. pneumoniae in the third one. There was not seen any association of skin and hub colonization with their presence in the catheter tip and in the blood of these patients, but S. aureus was recovered from nostril of those with sepsis by this pathogenic agent. A greater concern is suggested over preventive measures and control of these primary and secondary bloodstream, as well as catheter tip colonization.

Outbreaks associated to bloodstream infections with Staphylococcus aureus and coagulase-negative Staphylococcus spp in premature neonates in a university hospital from Brazil

Staphylococcus aureus e Estafilococos coagulase-negativa (ECN) estão entre os patógenos hospitalares mais importantes em pacientes de unidades de terapia intensiva neonatal, principalmente em infecções da corrente sanguínea. O principal objetivo deste estudo foi determinar a ocorrência de infecções hospitalares por estes microrganismos usando dois sistemas de vigilância (laboratorial e "National Nosocomial Infection Surveillance" - NNIS) e determinar os fatores de risco mais importantes durante o período de dois anos (2001-2002). Dois surtos por ambos S. aureus suscetível a meticilina (1.5por cento) e ECN resistente à meticilina (1.0 por cento) foram observados, de janeiro a fevereiro/02 e agosto a setembro/02. Taxas de incidência endêmica de 3.77 por cento e 5.16 por cento para S.aureus e ECN foram detectadas respectivamente. Fatores de risco incluíram idade £7 dias, hospitalização 7 dias e utilização de cateter vascular central (CVC) de polietileno através de dissecação de veia (flebotomia), mas, nenhum desses fatores independentes foram confirmados pela análise multivariada. Por outro lado, ECN resistente à oxacilina prevaleceu (66.0 por cento) nos episódios epidêmicos. Análise molecular através de gel de eletroforese em campo pulsátil mostrou a natureza policlonal das amostras de S. aureus. Em conclusão, nós identificamos dois surtos de etiologia mista por S. aureus suscetível à meticilina e ECN resistente à meticilina associados à falta de material adequado (cateter vascular central) para neonatos, relacionados a procedimento invasivo. Os dois surtos foram controlados com a substituição de CVC de polietileno pelo cateter central de inserção periférica.

An outbreak of Acinetobacter baumannii septicemia in a neonatal intensive care unit of a university hospital in Brazil

We studied an outbreak of two multi-drug resistant clones of Acinetobacter baumannii in the Neonatal Intensive Care Unit of the Uberlândia Federal University Hospital in Minas Gerais state, Brazil, and we analyzed the contribution of cross-transmission in the rise in infection rates. Eleven neonates who developed multi-drug resistant A. baumannii nosocomial infection were matched to 22 neonates who were admitted to the same unit and did not develop an infection during the outbreak period, in order to identify risk factors for infection. Three out of the 11 neonates died. Epidemiological investigation included molecular typing, using pulsed field gel electrophoresis. Prior to the outbreak, from December 2001 to March 2002, no case of infection by this microorganism was diagnosed. Environmental and healthcare worker hand cultures were negative. Nine isolates had similar pulsed field gel electrophoresis patterns and two had another clone. The first clone was brought into the unit by an infected patient who was transferred from another hospital without a history of antibiotic use. The second clone did have its origin clearly defined. Both infected groups led us to conclude that several factors contributed to infection with A. baumannii. These factors were: exposure to antibiotics and invasive devices, birth weight < 1500g, age < 7 days and duration of hospitalization > 7 days. Based on logistic regression, infected neonates were more exposed to carbapenem and mechanical ventilation than the control group. Cross transmission between infants contributed to the rise in the rates of multi-drug resistant A. baumannii infection.

Analysis of the genetic diversity of vancomycin-resistant Staphylococcus aureus

Staphylococcus aureus resistente à meticilina (MRSA) e Staphylococcus coagulase negativo resistente à meticilina (MRCoNS) são os agentes mais freqüentes em infeccões hospitalares mundialmente, justificando o incremento no uso de vancomicina. Neste estudo avaliamos a presenca de Staphylococcus resistentes aos glicopeptideos em 41 pacientes, em uso de vancomicina, hospitalizados no Hospital de Clínicas da Universidade Federal de Uberlândia em Uberlândia-MG. Todos os isolados foram semeados em agar Mueller-Hinton acrescido do antimicrobiano. A resistência a vancomicina foi confirmada por crescimento após incubacão por 24-48 horas a 35ºC. A heterorresistência foi avaliada por semeadura com inóculo mais denso (108 UFC/mL). Um paciente com nefrite, no programa de hemodiálise teve o fenótipo de Staphylococcus aureus com resistência intermediária à vancomicina (VISA) (CIM= 8 mg/mL) e em oito pacientes as amostras apresentaram heterorresistência (hVISA). Além do uso prévio de vancomicina outros fatores de risco incluindo três ou mais antimicrobianos, cirurgia e três ou mais procedimentos invasivos, foram observados. A análise molecular foi realizada por amplificacão randômica de DNA polimórfico em reacão em cadeia da polimerase (RAPD-PCR) mostrando dois clusters com duas amostras cada um, em pacientes cirúrgicos, com relacão temporal espacial e com perfil de susceptibilidade semelhantes quando frente à vários outros antimicrobianos.

Infection and colonization by Gram-negative bacilli in neonates hospitalized in High Risk Nursery at Uberlandia Federal University Hospital: etiology, resistant phenotypes and risk factors

Os objetivos deste estudo foram determinar infecções endêmicas e epidêmicas por bacilos Gram-negativos, fatores de risco associados a colonização e infecção e a presença dos fenótipos de resistência ESBL e AmpC em neonatos admitidos em Berçário de Alto Risco. Durante um período de 21 meses, foi realizado um estudo prospectivo para avaliar os casos de infecções hospitalares e o uso de cefalosporinas de terceira geração; e um estudo caso-controle para determinar os fatores de risco associados a colonização/infecção. Quatro inquéritos de colonização da orofaringe e intestino dos neonatos (Setembro e Novembro/2001, Fevereiro e Agosto/2002). Amostras com resistência a 2 mg/mL de ceftazidima foram isoladas devido a suspeita de produção de b-lactamases (ESBL/ AmpC). A incidência de pacientes infectados por bacilos Gram-negativos foi de 2,4% (89/3.709 neonatos), sendo sepse (35,9%) e conjuntivite (31,4%) as síndromes mais frequentes. A maioria das infecções foram endêmicas (73,9%) e associadas a Enterobacteriaceae (95,5%), estes também foram relacionados à colonização, correspondendo principalmente as amostras de Enterobacter spp e Klebsiella spp.. Foram identificados dois surtos, durante o estudo, associados a Pseudomonas aeruginosa (N=10) e Acinetobacter baumannii (N=11). Os fatores de risco incluindo: tempo de internação, uso de antimicrobianos, ventilação mecânica, cateter vascular central, cirurgia e nutrição parenteral foram significativos em uma análise univariada e considerados um risco para infecção por bacilos Gram-negativos. A maioria das amostras de Enterobacteriaceae (80,9%) com resistência a 2 mg/mL de ceftazidima foram do fenótipo ESBL. O uso de cefalosporinas de terceira geração (ceftriaxona) na unidade neonatal favoreceu a emergência de bacilos Gram-negativos multiresistentes.

Infection and colonization by Staphylococcus aureus in a high risk nursery of a Brazilian teaching hospital

Neonates are susceptible to nosocomial infections due to immunological immaturity, prolonged hospital stay and the use of invasive procedures. We evaluated the incidence of infections and the prevalence of colonization by MRSA (Methicillin-resistant Staphylococcus aureus) and MSSA (Methilin-susceptible Staphylococcus aureus), as well as colonization risk factors. Staphylococcal infections were observed by analyzing medical records in the HICS (Hospital Infection Control Service) and the HRN (High Risk Nursery). Additionally, four inquiries concerning colonization prevalence were made for S. aureus, from January/2000 to December/2002. Clinical specimens from the nostrils, mouth and anus were cultivated in mannitol-salt agar plates and identification was made through standard methods. The frequency of neonates colonized by S. aureus was 49 percent. MSSA was more prevalent (57 percent) than MRSA (43 percent). Risk factors related to the acquisition of MRSA were: low weight and antibiotic use. , Hospital stay was the only variable significantly associated with colonization by S. aureus. The incidence of infections by S. aureus during the last three years was 2.18 percent (159 cases). Nine of them (5.5 percent) were associated with MRSA and 150 (94.5 percent) with MSSA. Staphylococcal infections were considered as invasive (sepsis) and non-invasive (conjunctivitis, cutaneous), corresponding to 31 percent and 69 percent, respectively. The MRSA phenotype in infection was rare compared with methicillin-susceptible samples, although S. aureus, MRSA and MSSA colonization rates were high.

Comparing hospital infections in the elderly versus younger adults: an experience in a Brazilian University Hospital

The elderly population will grow rapidly over the next 25 years, however there is little information about hospital infections in this group of patients in Brazil. We examined the prevalence of nosocomial and community infections in elderly (>65 years) patients and their relationship with intrinsic and extrinsic risk factors in a Brazilian University Hospital. A total of 155 hospitalized elderly patients were evaluated, and clinical and demographic information about each patient was obtained from hospital records. The rates of nosocomial and community infections were 16.1 percent and 25.6 percent, respectively. When the elderly group with and without nosocomial infections was analyzed, practically all the risk factors considered (use of antibiotics, invasive devices, surgery and time of hospitalization) were significantly more associated with the patients with hospital infection. All patients with nosocomial infections were taking antibiotics and most of them (56.0 percent) were being treated with two or more antibiotics; the length of hospitalization was double (p=0.007) compared to patients who had not acquired hospital infection. The most frequent sites of nosocomial and community infections were surgical (56.0 percent) and the skin (37.1 percent), and most of the patients (47.5 percent) were in the surgical clinic wards. In conclusion, the elderly patients were more likely to develop a nosocomial infection (16.1 percent prevalence) . Surgical infection accounted for the majority (56.0 percent) of the nosocomial infections, in contrast with North American studies that indicate urinary tract infections to be the commonest

Analysis of the clonal diversity of Staphylococcus aureus methicillin-resistant strains isolated at Joäo Pessoa, state of Paraíba, Brazil

To investigate the clonal diversity of Staphylococcus aureus strains isolated at Joäo Pessoa, state of Paraíba, Brazil, digested genomic DNA were studied by pulsed-field gel electrophoresis (PFGE) in nine methicillin-resistant strains (MRSA) and three methicillin-sensitive strains (MSSA), selected among 67 isolates based on their antimicrobial susceptibility and epidemiology. The isolates were obtained between April and November 1992 from the Hospital of the Federal University of Paraíba, located in Joäo Pessoa. Two MRSA isolates from the Oswaldo Cruz Hospital, Säo Paulo, Brazil, including an epidemic strain previously detected from different hospitals at the country were used as control. Five different patterns, were demonstrated by MRSA isolated in Joäo Pessoa and these patterns were described in several epidemiologically unrelated hospitals in Säo Paulo. Our results suggest the interstate dissemination of a MRSA clone in Joäo Pessoa which is similar to that described in other cities of Brazil.

Antimicrobial susceptibilities and phage typing of hospital and non-hospital strains of methicilin-resistan Staphylococcus aureus isolated from hands

Foi realizado um estudo comparativo sobre o carreamento de amostras de Staphylococcus aureus resistentes a meticilina pelas mäos de indivíduos pertencentes a um grupo intra-hospitalar e aqueles pertencentes a um grupo extra-hospitalar (grupo controle). Empregando-se a técnica do saco plástico, quatro subgrupos de 5 indivíduos foram analisados, a intervalos semanais, durante 4 semanas. Entre as 349 amostras de estafilococos obtidas, 19/105 (18.09%) e 20/244 (8.19%) foram isoladas a partir das mäos de indivíduos pertencentes, respectivamente, aos grupos intra e extra-hospitalar e foram identificadas como S. aureus. Foi verificado que todas as amostras de S. aureus produziram beta-lactamases e a maioria (35/39; 89,74%) se apresentou resistente a meticilina. Quinze diferentes fagotipos foram identificados, sendo a maioria incluída no fagogrupo III. Os resultados demonstraram que amostras de S. aureus resistentes a meticilina säo freqüententemente encontradas nas mäos e enfatizam o possível papel das mäos como fonte ou via de disseminaçäo desses microrganismos