to be from 2.5 to 5.5 cases per 1,000 catheter-day. the clinical impact is relevant and increases the cost of the HD Unit. Methods: The present study is the irst of 2 phases. It was conducted from January to December of 2012, and included all patients and nurses who were in the HD Unit. The prevalence of Gramnegative bacilli (GNB) and methicillin-resistant Staphylococcus aureus (MrSA) colonizing the nasal passages and the skin is described. Also, phenotypic association was sought by genus, species and sensitivities between colonizing bacterial strains and blood cultures with GNB and MRSA. Results: the study included 70 patients and 10 nurses. the prevalence of nasal colonization in patients by GNB was 9% and 6% in the pericatheter, and no nursing GNB colonization was discovered. The prevalence of MRSA nasal colonization was 19% and 6% in the pericatheter for patients and in the nurses the nasal colonization was 50% and 10% in the hands. We identiied 29 cases of primary bacteremia. The primary bacteremia rate is 1.5 per 1,000 catheter-day or 0.4 episodes per patient per year. Conclusion: We demonstrated a high prevalence of MrSA colonization in patients and nurses in the HD Unit. No relationship was found between primary bacteremia by GNB and patients and

nurses’ bacteria colonization by the phenotypic comparison

Cárdenas de la Garza, J. A.

Flores Pérez, R. O.

Ibarra Sifuentes, Héctor Raúl

Quiñonez Olivas, Carlos

Rivera Morales, Irma

Sánchez Martínez, Concepción

Flores Pérez, Rómulo Omar

Repositorio Academico Digital UANL

Medicina Universitaria 2014;16(64):125-128www.elsevier.com.mxmedicinauniversitaria* Corresponding author: Internal Medicine Department, “Dr. José Eleuterio González” University Hospital. Francisco I. Madero and Gonza-litos Avenue, Mitras Centro, Monterrey, N.L., Mexico. Phone: (81) 8389 1111, ext. 3243, 3107. E-mail address: carlos_quinonez@hotmail.com (C. G. Quiñonez-Olivas).OrIGINAL ArtICLePrevalence of colonizing bacteria and their association with primary bacteremias in hemodialysis of a university hospitalC. G. Quiñonez-Olivasa,*, I. M. Rivera-Moralesb, C. Sánchez-Martínezc, H. R. Ibarra-Sifuentesa, R. O. Flores-Pérezc, J. A. Cárdenas-de la Garzada Internal Medicine Department, “Dr. José Eleuterio González” University Hospital, Universidad Autónoma de Nuevo León, Monterrey, N.L., Mexicob Infectious Disease Service, “Dr. José Eleuterio González” University Hospital, Universidad Autónoma de Nuevo León, Monterrey, N.L., Mexicoc Nephrology Service, “Dr. José Eleuterio González” University Hospital, Universidad Autónoma de Nuevo León, Monterrey, N.L., Mexicod School of Medicine, Universidad Autónoma de Nuevo León, Monterrey, N.L., Mexicoreceived: December 2013; Accepted: June 2014KEYWORDS Colonization; Primary bacteremia; Hemodialysis; Gram-negative bacilli; Methicillin-resistant Staphylococcus aureus; Mexico.AbstractIntroduction: the incidence of primary bacteremia in patients on hemodialysis (HD) is reported to be from 2.5 to 5.5 cases per 1,000 catheter-day. the clinical impact is relevant and increases the cost of the HD Unit. Methods: The present study is the irst of 2 phases. It was conducted from January to December of 2012, and included all patients and nurses who were in the HD Unit. The prevalence of Gram-negative bacilli (GNB) and methicillin-resistant Staphylococcus aureus (MrSA) colonizing the nasal passages and the skin is described. Also, phenotypic association was sought by genus, species and sensitivities between colonizing bacterial strains and blood cultures with GNB and MRSA. Results: the study included 70 patients and 10 nurses. the prevalence of nasal colonization in patients by GNB was 9% and 6% in the pericatheter, and no nursing GNB colonization was disco-vered. The prevalence of MRSA nasal colonization was 19% and 6% in the pericatheter for pa-tients and in the nurses the nasal colonization was 50% and 10% in the hands. We identiied 29 cases of primary bacteremia. The primary bacteremia rate is 1.5 per 1,000 catheter-day or 0.4 episodes per patient per year. Conclusion: We demonstrated a high prevalence of MrSA colonization in patients and nurses in the HD Unit. No relationship was found between primary bacteremia by GNB and patients and nurses’ bacteria colonization by the phenotypic comparison. 1665-5796 © 2014 Revista Medicina Universitaria. Facultad de Medicina UANL. Publicado por Elsevier México. Todos los derechos reservados.Documento descargado de http://www.elsevier.es el 24-08-2016126 C. G. Quiñonez-Olivas et alIntroductionthe incidence of primary bacteremia in hemodialysis (HD) patients is reported to be between 2.0% and 4.5% per 1,000 catheter-day, or one to 2 episodes per patient-year. the use of HD catheters is a major mortality predictor in HD pa-tients.1 Primary bacteremia is the most common cause of morbidity and the second most common cause of mortality in HD patients.2 Staphylococcus aureus (S. aureus) causes up to 80% of vascular access infections and between 15% and 30% are caused by methicillin-resistant S. aureus (MrSA).3Only a few studies have researched Gram-negative bacilli (GNB’s) nasal and skin colonization.4 there are reports in medical literature of a low incidence of catheter-related GNB infections, theoretically it is attributed to those who have a lesser adherence to vascular endothelial contrary to Gram-positive cocci.5,6 GNB, which colonizes nasal mucus and the pericatheter in patients in peritoneal dialysis has not showed a major association with infections in the dialy-sis catheter’s exit point, nor in the development of peritoni-tis associated with peritoneal dialysis.7,8 Conversely, a discrete association between nasal and skin colonization by GNB and vascular access infection in HD patients has been demonstrated.8,9 the number of hemodialysis-related primary bacteremias increased notoriously in our Hospital between 2010 and 2011, with a predominance of GNB in up to 60% of patients. On the other hand, as described in medical literature, MrSA is the causal pathogen of primary bacteremia with the hig-hest morbidity; however its prevalence is unknown.For this reason we focused this study on inding the preva-lence of GNB and MrSA in patients and healthcare staff and their association with primary bacteremia developed in the HD Unit of the “Dr. José Eleuterio González” University Hos-pital.Methods The present study was conducted at the Renal Unit of the “Dr. José Eleuterio González” University Hospital, from Ja-nuary to December of 2012, including all patients and nur-sing staff in the HD Unit. We used the following operational deinition for primary bacteremia: The presence of bacteria in the blood stream in a patient with a vascular catheter for over 48 hours, with positive hemoculture and clinical mani-festation of infections without any other infectious focus. The study was divided into 3 stages:I. Supervision of a cohort of patients in the HD pro-gram in order to identify primary bacteremia ca-ses and determine the rate of primary bacteremia per 1,000 catheter-day and patient-year episo-des. We identiied the patients who developed fever du-ring HD and we performed a hemoculture to moni-tor them in the bacteriology lab and verify GNB and MrSA isolations. We calculated the rate of pri-mary bacteremia per 1,000 catheter-day and pa-tient-year episodes. II. Detection of patients colonized by GNB and MrSA in nasal mucous and pericatheter skin, also detec-tion of nasal mucous and hands colonization in the nursing staff on the HD Unit; and determination of the prevalence of colonization in both groups.We performed a nasal swab culture and pericathe-ter skin in all patients in the HD Unit, and we per-formed nasal and predominant hand swabs in the healthcare personnel involved in the connection of patients in HD. Subsequently, we determined nasal and skin colonization prevalence in both groups. III. Determination of phenotypic association between GNB’s isolated from primary bacteremias and GNBs colonizing the nasal mucous and skin.We identiied bacteria genus and species in all bac-teremia cases, as well as the colonizing strains, using conventional biochemistry performed by the clinical pathology lab. We carried out antibiotic susceptibility testing (AST) in the following GNBs: ceftazidime, ciproloxacin and amikacin. In the S. aureus we performed the AST to cefoxitin and if it wasn’t sensitive to this antibiotic we determined its methicillin resistance. We searched for an asso-ciation between GNB’s isolated from primary bac-teremia and colonizing GNB’s through phenotypic comparison with genus, species and sensitivities described in the antibiogram. In a second stage of the same study we determined whether or not isola-ted MRSA’s were clones using pulsed ield electro-phoresis. The results were analyzed with descriptive statistics in frequencies and proportions.ResultsWe conducted colonization cultures from each of the 70 pa-tients in the HD Unit. We documented nasal colonization in 47 patients (67%) and 50 isolations because 3 patients had 2 bacteria colonizing the nasal mucous. Pericatheter coloni-zation was evidenced in 27 patients (39%) and 29 isolations because 2 patients had 2 bacteria colonizing the pericathe-ter skin. the most relevant nasal and pericatheter skin-co-lonizing isolations can be found in tables 1 and 2.Table 1 Nasal colonizations in patients of the Hemodialysis Unit of the “Dr. José Eleuterio González” University Hospital. Nasal n=50* Frequency %Methicillin-sensitive Staphylococcus aureus 21 42Methicillin-resistant Staphylococcus aureus 13 26Escherichia coli 3 6Klebsiella pneumoniae 1 2Acinetobacter baumanii 1 2Morganella morganii 1 2*the frequencies do not add up to the total number of colonies (n=50) because we did not add coagulase-negative Staphylococcus, which is not considered a pathogenic lora.Documento descargado de http://www.elsevier.es el 24-08-2016Prevalence of colonizing bacteria and their association with primary bacteremias in hemodialysis of a  university hospital 127Regarding healthcare personnel in the HD Unit, we docu-mented nasal colonization in 10 nurses (100%) and 10 isola-tions. We found colonization in the predominant hand in 3 nurses (30%) and 3 isolations. The most relevant nasal and predominant hand colonizations in healthcare personnel can be found in table 3.the prevalence of nasal colonization in patients by MrSA was 19% and by GNB, 9%; the prevalence in pericatheter skin by GNB and MRSA was 6% for both. Regarding the nur-sing staff, the prevalence of nasal colonization by MRSA was 50% and 10% in the predominant hand; we did not ind GNB colonization.During the study we identiied 29 primary bacteremia ca-ses conirmed microbiologically. The rate of bacteremia caused by GNB was 28%, you can read each of the percentages on bacteremia-isolated GNBs in Figure 1. Primary bactere-mias caused by S. aureus were 12 (67%) and 25% was by MrSA, you can read each percentage of bacteremia-isolated CGP in Figure 2. Primary bacteremia rate was 1.5 per 1,000 catheter-day or 0.4 episodes per patient-year. In the pa-tients with isolations by GNB in their primary bacteremia blood cultures, none of them displayed phenotypic associa-tion with nasal mucous and skin (Table 4). Discussion A low prevalence of GNB colonization in patients was de-monstrated, with 6% and 9% for skin and nasal mucous res-pectively, similar to the rate described in medical literature. Prevalence of MRSA colonization was 6% and 19% for skin and nasal mucous respectively.10 In healthcare personnel, a pre-valence of 10% in the predominant hand and 50% in nasal mucous was demonstrated, between both groups this means that at least one in every 3 individuals is an MrSA carrier.Primary bacteremia rate was 1.5 per 1,000 catheter-day or 0.4 episodes per patient-year, lower than the rate repor-ted in international literature.11 Bacteremias caused by MRSA were 10%, but there is no previous information regarding our grounds to compare to previous years. Primary bactere-mias caused by GNB were 28%, representing a reduction of over 50% of the cases identiied as GNB in the years 2010 and 2011, during which it was 60% of the total of bacteremias. The reduction of primary bacteremias by GNB during the present study with regard to the last 2 years is probably caused by hygiene actions performed by the nephrology department at the beginning of that year, including the standardization of asepsis of the pericatheter region with chlorhexidine, and ha-ving enough supplies for proper hand-washing, such as alcohol antibacterials and electronic-sensor sinks.In conclusion, an association between carriers (patients) of GNB and primary bacteremias by GNB was not proved, which is consistent with other epidemiologic studies. In addition, a high prevalence of colonizing MrSA in patients and nursing staff in the HD Unit was demonstrated.EnterobactercloacaeEscherichiacoliPseudomonaaeuruginosa0 10 20 30 40 50 60 70Figure 1 the percentage of each of the Gram-negative bacilli isolated from the primary bacterimias.Table 2 Bacterial colonies of pericatheter skin in patients of the Hemodialysis Unit of the “Dr. José Eleuterio González” University Hospital.Pericatheter skin n=29* Frequency %Methicillin-sensitive Staphylococcus aureus 14 48Methicillin-resistant Staphylococcus aureus 4 14Klebsiella pneumoniae 3 11Pseudomona aeruginosa 1 3*the frequencies do not add up to the total number of colonies (n=29) because we did not add coagulase-negative Staphylococcus, which is not considered a pathogenic lora.Table 3 Bacterial colonies in the nasal mucous and dominant hand of the healthcare personnel of the Hemodialysis Unit of the “Dr. José Eleuterio González” University Hospital. Nasal n=10*  Frequency  % Methicillin-resistant Staphylococcus aureus 5 50 Methicillin-sensitive Staphylococcus aureus 4 40 Dominant hand n=3* Frequency %Methicillin-sensitive Staphylococcus aureus 1 33Methicillin-resistant Staphylococcus aureus 1 33*the frequencies do not add up to the total number of colonies (n) because we did not add coagulase-negative Staphylococcus, which is not considered a pathogenic lora.Documento descargado de http://www.elsevier.es el 24-08-2016128 C. G. Quiñonez-Olivas et alConlicts of interestThe authors have no conlicts of interest to declare.FundingNo inancial support was provided.References1. O’Grady NP, Alexander M, Burns LA, et al. Guidelines for the prevention of intravascular catheter-related infections. Clini-cal infectious diseases: an oficial publication of the Infectious Diseases Society of America 2011;52:162-193.2. Alexander eL, Morgan DJ, Kesh S, et al. Prevalence, persisten-ce, and microbiology of Staphylococcus aureus nasal carriage among hemodialysis outpatients at a major New York Hospital. Diagn Microbiol Infect Dis 2011;70:37-44.3. Allon M, Daugirdas J, Depner tA, et al. effect of change in vascular access on patients mortality in hemodialysis patients. American journal of kidney disease: the oficial journal of the National Kidney Foundation 2006;47:469-477.4. Katneni r, Hedayati, S Susan. Central venous catheter-related bacteremia in chronic hemodialysis patients: epidemiology and evidence-based management. Nature Clinical Practice Nephro-logy 2007;3:256-266.5. Choi CS, Yin CS, Bakar AA, et al. Nasal carriage of Staphylococ-cus aureus among healthy adults. J Microbiol Immunol Infect 2006;39:458-464.6. Mermel LA. Prevention of intravascular catheter-related infec-tions. Ann Intern Med 2000;132:391–402.7. Burton DC, Edwards JR, Horan TC, et al. Methicillin-resistant Staphylococcus aureus central line-associated bloodstream in-fections in US intensive care units, 1997–2007. JAMA 2009;301:727–736.8. Gaynes R, Edwards JR. Overview of nosocomial infections cau-sed by gram-negative bacilli. Clin Infect Dis 2005;41:848–854.9. Yazgi H, Ertek M, Ozbek A, et al. Nasal carriage of Staphylococ-cus aureus in hospital personnel and the normal population and antibiotic resistance of the isolates. Mikrobiyol Bul 2003;37:137-142.10. Kaplowitz LG, Comstock JA, Landwehr DM, et al. Prospective study of microbial colonization of nose and skin and infection of the vascular access in hemodialysis patients. J Clin Microbiol 1988;26:1257-1262.11. Cisneros-Herreros J, Cobo-reinoso J, Pujol-rojo M, et al. Guía para el diagnóstico y tratamiento del paciente con bacteremia. Guías de la Sociedad española de enfermedades Infecciosas y Microbiologia Clinica (SeIMC). enfermedades Infecciosas y Mi-crobiologia Clinica 2007;25:111-130.Table 4 Example of the phenotypic association between Gram-negative bacilli. It shows that this Gram-negative bacilli with the same genus and specie (i. e. Pseudomonas aeruginosa) colonizing (C) does not have the same antibiotic sensitivity as the Pseudomonas aeruginosa isolated in bacteremias (B), which demonstrates that there is no association between the bacteria that colonizes and that pathogenic bacteria isolated in the bacteremia hemocultures. Bacteria Amikacin Ciproloxacin CeftazidimePseudomona aeruginosa Bacterimia (B) *09/07/12 Sensitive Sensitive resistantPseudomona aeruginosa (B)*15/07/12 Sensitive Sensitive resistantPseudomona aeruginosa (B)*16/07/12 Sensitive Sensitive resistantPseudomona aeruginosa (B)*04/08/12 Sensitive Sensitive resistantPseudomona aeruginosa Colonizing (C)*23/04/12 Sensitive Sensitive Sensitive*The dates show when the bacteria were isolated in the bacteremia and as a colony on the skin.EnterococofecalisStaphylococcus coagulasa negativoStaphylococcus aureussensible a meticilinaStaphylococcus aureusresistente a meticilina0 5 10 15 20 25 30 35 40 45 50Figure 2 the percentage of each of the Gram-positive cocci isolated from the primary bacterimias.Documento descargado de http://www.elsevier.es el 24-08-2016

Prevalence of colonizing bacteria and their association with primary bacteremias in hemodialysis of a university hospital

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Prevalence of colonizing bacteria and their association with primary bacteremias in hemodialysis of a university hospital

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