Fungemia due to opportunistic fungi in patients with cancer.

BACKGROUND: Fungemia due to uncommon fungi and secondary to multiple risk factors has become an emergent health problem, particularly in oncology patients. AIMS: This study shows the following data collected during an 11-year period in a tertiary care oncologic center from patients with fungemia: demographic data, clinical characteristics, and outcome. METHODS: A retrospective study was performed at Instituto Nacional de Cancerología, a 135-bed referral cancer center in Mexico City, from July 2012 to June 2023. All episodes of non-Candida fungemia were included. RESULTS: Sixteen cases with uncommon fungemia were found in the database, representing 0.3% from all the blood cultures positive during the study period, and 8.5% from all the fungi isolated. The most common pathogens identified in our series were Histoplasma capsulatum, Acremonium spp., Trichosporon asahii, and Saccharomyces cerevisiae. Eight patients had hematologic malignancies, and five had severe neutropenia. In eight cases fungemia was considered catheter-related, in four cases was classified as primary, and in the last four it was diagnosed as disseminated fungal diseases. Mortality at 30 days was 43.8%. CONCLUSIONS: The improved diagnostic tools have led to a better diagnosis of uncommon fungal infections. More aggressive therapeutic approaches, particularly in patients with malignancies, would increase survival rates in these potentially fatal diseases.

Multidrug-Resistant Staphylococcus sp. and Enterococcus sp. in Municipal and Hospital Wastewater: A Longitudinal Study.

The objective of the study was to detect multidrug-resistant Staphylococcus sp. and Enterococcus sp. isolates in municipal and hospital wastewater and to determine their elimination or persistence after wastewater treatment. Between August 2021 and September 2022, raw and treated wastewater samples were collected at two hospital and two community wastewater treatment plants (WWTPs). In each season of the year, two treated and two raw wastewater samples were collected in duplicate at each of the WWTPs studied. Screening and presumptive identification of staphylococci and enterococci was performed using chromoagars, and identification was performed with the Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI-TOF MS®). Antimicrobial susceptibility was performed using VITEK 2® automated system. There were 56 wastewater samples obtained during the study period. A total of 182 Staphylococcus sp. and 248 Enterococcus sp. were identified. The highest frequency of Staphylococcus sp. isolation was in spring and summer (n = 129, 70.8%), and for Enterococcus sp. it was in autumn and winter (n = 143, 57.7%). Sixteen isolates of Staphylococcus sp. and sixty-three of Enterococcus sp. persisted during WWTP treatments. Thirteen species of staphylococci and seven species of enterococci were identified. Thirty-one isolates of Staphylococcus sp. and ninety-four of Enterococcus sp. were multidrug-resistant. Resistance to vancomycin (1.1%), linezolid (2.7%), and daptomycin (8.2%/10.9%%), and a lower susceptibility to tigecycline (2.7%), was observed. This study evidences the presence of Staphylococcus sp. and Enterococcus sp. resistant to antibiotics of last choice of clinical treatment, in community and hospital wastewater and their ability to survive WWTP treatment systems.

Pseudomonas fluorescens CRBSI outbreak: complying with the standardization of invasive procedures is a step ahead in the fight against antimicrobial resistance.

In the healthcare sector, the implementation of standardized procedures, such as those commonly employed in franchises to ensure consistent quality, remains underprioritized. Within this framework, we focus on the importance of standardized central venous catheter (CVC) insertion procedures to prevent healthcare-associated outbreaks. While antimicrobial resistance (AMR) may still not be the most prevalent problem in some institutions, its increasing significance certainly underlines the urgency of infection prevention.We aim to highlight this issue by describing and discussing an outbreak scenario of carbapenem-resistant (CR) Pseudomonas fluorescens bloodstream infections resulting from a deviation from the standardized CVC insertion procedure. This outbreak led to six episodes of catheter related bloodstream infection (CRBSI) in patients with hematologic malignancies, delaying their primary treatment. Nineteen patients were exposed, leading to an attack rate of 31.6%.

Bacteremia caused by Aeromonas species in patients with cancer: Clinical manifestations and outcomes.

INTRODUCTION: Oncologic patients can have severe infections due to Aeromonas. This study aims to investigate the clinical characteristics and outcomes of cancer patients with bloodstream infections (BSI) caused by Aeromonas. METHODOLOGY: We included patients with bacteremia caused by Aeromonas species from 2011 to 2018. RESULTS: Seventy-five BSI events in the same number of patients were identified. Forty patients were men (53.3%); the mean age was 49 years (IQR 28-61). A. caviae was the most frequent isolate (n = 29, 38.6%), followed by A. hydrophila (n = 23, 30.6%), A. sobria (n = 15, 20%), and A. veronii (n = 8, 10.6%). The most frequent underlying diagnosis was hematologic malignancy (n = 33, 44%), followed by breast cancer (n = 12, 16%) and gastrointestinal tract cancer (n = 8, 10.6%). The most frequent type of bacteremia was CRBSI in 32 cases (42.6%), followed by mucosal barrier injury-laboratory confirmed BSI (n = 20, 26.7%). Sixteen (26.2%) were hospital-acquired BSI. Attributable mortality occurred in 11 patients (14.6%). In univariate analysis A. hydrophila bacteremia, liver failure, skin/soft tissue infection, septic shock, inappropriate antimicrobial treatment, and relapse or cancer progression were associated with 30-day mortality. In multivariate analysis, only septic shock, inappropriate antimicrobial treatment, and relapse or cancer progression were associated with 30-day mortality. CONCLUSIONS: Aeromonas species should be considered one of the causative pathogens of healthcare-associated bacteremia, especially in immunocompromised patients. In addition, it can be associated with high fatality, particularly in patients with severe clinical infections.

Candida bloodstream infection in patients with cancer: A retrospective analysis of an 11-year period.

BACKGROUND: Candida bloodstream infection (CBSI) is a growing problem among patients with cancer. AIM: To describe the main clinical and microbiological characteristics in patients with cancer who suffer CBSI. METHODS: We reviewed the clinical and microbiological characteristics of all patients with CBSI diagnosed between January 2010 and December 2020, at a tertiary-care oncological hospital. Analysis was done according to the Candida species found. Multivariate logistic regression analysis was used to determine the risk factors associated with 30-day mortality. RESULTS: There were 147 CBSIs diagnosed, 78 (53%) in patients with hematologic malignancies. The main Candida species identified were Candida albicans (n=54), Candida glabrata (n=40) and Candida tropicalis (n=29). C. tropicalis had been mainly isolated from patients with hematologic malignancies (79.3%) who had received chemotherapy recently (82.8%), and in patients with severe neutropenia (79.3%). Seventy-five (51%) patients died within the first 30 days, and the multivariate analysis showed the following risk factors: severe neutropenia, a Karnofsky Performance Scale score under 70, septic shock, and not receiving appropriate antifungal treatment. CONCLUSIONS: Patients with cancer who develop CBSI had a high mortality related with factors associated with their malignancy. Starting an empirical antifungal therapy the soonest is essential to increase the survival in these patients.

Comparison of Lateral Flow Immunochromatography and Phenotypic Assays to PCR for the Detection of Carbapenemase-Producing Gram-Negative Bacteria, a Multicenter Experience in Mexico.

The identification of carbapenemase-producing Enterobacterales and Pseudomonas aeruginosa is important for treating and controlling hospital infections. The recommended methods for their identification require a long waiting time, technical training, and expertise. Lateral flow immunoassays such as NG-Test CARBA 5® overcome these needs. We analyzed 84 clinical isolates of carbapenem-resistant Enterobacterales and P. aeruginosa from four different hospitals in a two-year period. Antimicrobial resistance patterns were confirmed with the broth dilution method. Evaluation of KPC, VIM, NDM, IMP, and OXA-48-like enzymes was performed and compared to NG-Test CARBA 5 and phenotypic assays. Enterobacterales represented 69% of isolates and P. aeruginosa represented 31%. Carbapenemase-producing strains were 51 (88%) of Enterobacterales and 23 (88.4%) of P. aeruginosa; 20 (34%) and 23 (88%) were Class B ß-lactamases, respectively. The NG-Test CARBA 5® assay for Enterobacterales showed high sensitivity (98%), specificity (100%), and PPV (100%); however, it did not for P. aeruginosa. The Kappa concordance coefficient was 0.92 for Enterobacterales and 0.52 for P. aeruginosa. NG-Test CARBA 5® is a fast and easy-to-use assay. In Enterobacterales, we found excellent agreement in our comparison with molecular tests. Despite the low agreement in P. aeruginosa, we suggest that this test could be used as a complementary tool.

High mortality in an outbreak of multidrug resistant Acinetobacter baumannii infection introduced to an oncological hospital by a patient transferred from a general hospital.

OBJECTIVE: To describe the clinical features, outcomes, and molecular epidemiology of an outbreak of multidrug resistant (MDR) A. baumannii. METHODS: We performed a retrospective analysis of all MDR A. baumannii isolates recovered during an outbreak from 2011 to 2015 in a tertiary care cancer hospital. Cases were classified as colonized or infected. We determined sequence types following the Bartual scheme and plasmid profiles. RESULTS: There were 106 strains of A. baumannii isolated during the study period. Sixty-six (62.3%) were considered as infection and 40 (37.7%) as colonization. The index case, identified by molecular epidemiology, was a patient with a drain transferred from a hospital outside Mexico City. Ninety-eight additional cases had the same MultiLocus Sequence Typing (MLST) 758, of which 94 also had the same plasmid profile, two had an extra plasmid, and two had a different plasmid. The remaining seven isolates belonged to different MLSTs. Fifty-three patients (50%) died within 30 days of A. baumanniii isolation: 28 (20%) in colonized and 45 (68.2%) in those classified as infection (p<0.001). In multivariate regression analysis, clinical infection and patients with hematologic neoplasm, predicted 30-day mortality. The molecular epidemiology of this outbreak showed the threat posed by the introduction of MDR strains from other institutions in a hospital of immunosuppressed patients and highlights the importance of adhering to preventive measures, including contact isolation, when admitting patients with draining wounds who have been hospitalized in other institutions.

Chromosome Architecture and Gene Content of the Emergent Pathogen Acinetobacter haemolyticus.

Acinetobacter haemolyticus is a Gammaproteobacterium that has been involved in serious diseases frequently linked to the nosocomial environment. Most of the strains causing such infections are sensitive to a wide variety of antibiotics, but recent reports indicate that this pathogen is acquiring very efficiently carbapenem-resistance determinants like the blaNDM-1 gene, all over the world. With this work we contribute with a collection set of 31 newly sequenced nosocomial A. haemolyticus isolates. Genome analysis of these sequences and others collected from RefSeq indicates that their chromosomes are organized in 12 syntenic blocks that contain most of the core genome genes. These blocks are separated by hypervariable regions that are rich in unique gene families, but also have signals of horizontal gene transfer. Genes involved in virulence or encoding different secretion systems are located inside syntenic regions and have recombination signals. The relative order of the synthetic blocks along the A. haemolyticus chromosome can change, indicating that they have been subject to several kinds of inversions. Genomes of this microorganism show large differences in gene content even if they are in the same clade. Here we also show that A. haemolyticus has an open pan-genome.

Microbiology and prevalence of E2SKAPE-resistant strains in catheter-related bloodstream infections in patients with cancer.

INTRODUCTION: Central venous catheters (CVCs) are essential for treating cancer patients, but infection is a risk associated with their use, particularly by multidrug-resistant (MDR) bacteria. The aim of this study was to describe the microbiology of catheter-related bloodstream infections (CRBSIs) in cancer patients and to compare the prevalence of MDR ESKAPE microorganisms (Enterococcus faecium, Staphylococcus spp, Klebsiella spp, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp) plus Escherichia coli (E2SKAPE). METHODS: Based on data from 2013 to 2015 from a prospective survey of CRBSIs by the intravenous therapy team, we describe the microbiology and compare the prevalence of MDR E2SKAPE strains between hospitalized patients and outpatients. RESULTS: A total of 469 episodes of CRBSI were diagnosed: 261 (62%) were in women; 87 (18.6%) occurred in hospitalized patients, and 382 (81.4%) in ambulatory patients; 27.5% of patients had a hematologic malignancy and 72.5% a solid tumor. The median time between CVC insertion and CRBSI was 116 days (interquartile range [IQR], 48-207). The most common bacteria isolated were Staphylococcus epidermidis (18.1%), S aureus (10.9%), E coli (7.7%), and Klebsiella spp (8.6%). E2SKAPE accounted for 35.6%. Methicillin-resistant Staphylococcus aureus (MRSA) (odds ratio [OR], 16.4; 95% confidence interval [CI], 1.6-114; P = .01), extended-spectrum beta-lactamase (ESBL) Klebsiella spp (OR, 26; 95% CI, 2-286; P = .007), and ESBL E coli (OR, 26; 95% CI, 2-286; P = .007) were significantly more frequently isolated from hospitalized vs ambulatory patients. CONCLUSIONS: MRSA, ESBL E. coli and ESBL Klebsiella spp were significantly more frequently isolated from hospitalized patients with CRBSI.

Colonization by fecal extended-spectrum ß-lactamase-producing Enterobacteriaceae and surgical site infections in patients with cancer undergoing gastrointestinal and gynecologic surgery.

BACKGROUND: Cancer patients are at increased risk of infection. Fecal carriage of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-PE) may increase this risk. There are few studies on the prevalence of ESBL-PE colonization and surgical site infections (SSIs). METHODS: This prospective cohort study included patients with gastrointestinal and gynecological malignancies who were admitted to the hospital for elective surgery. Rectal swab cultures were obtained on the day of admission and during the postoperative period every 5 days. Prevalence of ESBL-PE fecal colonization and risk factors for the development of SSI were assessed. RESULTS: We included 171 patients, 30 (17.5%) of whom were colonized with ESBL-PE at admission. This proportion increased to 21% (37 of 171) of the samples during the hospital stay. Incidence of SSI was 14.6% (n = 25). Ten of 37 (27%) patients colonized by ESBL-PE developed SSI versus 15 of 134 (11%) of the non-ESBL-PE (relative risk [RR], 2.163; 95% confidence interval [CI], 1.201-3.897; P = .016). Five patients developed a bloodstream infection, and 4 patients were colonized with ESBL-PE (RR = 4.02; 95% CI, 1.2-3.89; P = .008). CONCLUSIONS: The rate of ESBL-PE fecal colonization in surgical patients was 17.5%. Colonization of ESBL-PE duplicated the risk of SSI by the same strain and, by a factor of 4, the risk of bloodstream infections.

A snapshot of antimicrobial resistance in Mexico. Results from 47 centers from 20 states during a six-month period.

AIM: We aimed to assess the resistance rates of antimicrobial-resistant, in bacterial pathogens of epidemiological importance in 47 Mexican centers. MATERIAL AND METHODS: In this retrospective study, we included a stratified sample of 47 centers, covering 20 Mexican states. Selected isolates considered as potential causatives of disease collected over a 6-month period were included. Laboratories employed their usual methods to perform microbiological studies. The results were deposited into a database and analyzed with the WHONET 5.6 software. RESULTS: In this 6-month study, a total of 22,943 strains were included. Regarding Gram-negatives, carbapenem resistance was detected in ≤ 3% in Escherichia coli, 12.5% in Klebsiella sp. and Enterobacter sp., and up to 40% in Pseudomonas aeruginosa; in the latter, the resistance rate for piperacillin-tazobactam (TZP) was as high as 19.1%. In Acinetobacter sp., resistance rates for cefepime, ciprofloxacin, meropenem, and TZP were higher than 50%. Regarding Gram-positives, methicillin resistance in Staphylococcus aureus (MRSA) was as high as 21.4%, and vancomycin (VAN) resistance reached up to 21% in Enterococcus faecium. Acinetobacter sp. presented the highest multidrug resistance (53%) followed by Klebsiella sp. (22.6%) and E. coli (19.4%). CONCLUSION: The multidrug resistance of Acinetobacter sp., Klebsiella sp. and E. coli and the carbapenem resistance in specific groups of enterobacteria deserve special attention in Mexico. Vancomycin-resistant enterococci (VRE) and MRSA are common in our hospitals. Our results present valuable information for the implementation of measures to control drug resistance.

Microbiology and clinical characteristics of viridans group streptococci in patients with cancer

ABSTRACT This study assessed the microbiology, clinical syndromes, and outcomes of oncologic patients with viridans group streptococci isolated from blood cultures between January 1st, 2013 and December 31st, 2016 in a referral hospital in Mexico using the Bruker MALDI Biotyper. Antimicrobial sensitivity was determined using BD Phoenix 100 according to CLSI M100 standards. Clinical information was obtained from medical records and descriptive analysis was performed.Forty-three patients were included, 22 females and 21 males, aged 42 ± 17 years. Twenty (46.5%) patients had hematological cancer and 23 (53.5%) a solid malignancy. The viridans group streptococci isolated were Streptococcus mitis, 20 (46.5%); Streptococcus anginosus, 14 (32.6%); Streptococcus sanguinis, 7 (16.3%); and Streptococcus salivarius, 2 (4.7%). The main risk factors were pyrimidine antagonist chemotherapy in 22 (51.2%) and neutropenia in 19 (44.2%) cases, respectively. Central line associated bloodstream infection was diagnosed in 18 (41.9%) cases. Septic shock occurred in 20.9% of patients, with an overall mortality of 18.6%. Only four S. mitis revealed penicillin-resistance.Our results are similar to those of other series, identifying these bacteria as emerging pathogens with significant morbidity and mortality in oncologic patients. The MALDI-TOF system increased the rate of viridans group streptococci isolation in this population.

Microbiology and clinical characteristics of viridans group streptococci in patients with cancer.

This study assessed the microbiology, clinical syndromes, and outcomes of oncologic patients with viridans group streptococci isolated from blood cultures between January 1st, 2013 and December 31st, 2016 in a referral hospital in Mexico using the Bruker MALDI Biotyper. Antimicrobial sensitivity was determined using BD Phoenix 100 according to CLSI M100 standards. Clinical information was obtained from medical records and descriptive analysis was performed. Forty-three patients were included, 22 females and 21 males, aged 42 ± 17 years. Twenty (46.5%) patients had hematological cancer and 23 (53.5%) a solid malignancy. The viridans group streptococci isolated were Streptococcus mitis, 20 (46.5%); Streptococcus anginosus, 14 (32.6%); Streptococcus sanguinis, 7 (16.3%); and Streptococcus salivarius, 2 (4.7%). The main risk factors were pyrimidine antagonist chemotherapy in 22 (51.2%) and neutropenia in 19 (44.2%) cases, respectively. Central line associated bloodstream infection was diagnosed in 18 (41.9%) cases. Septic shock occurred in 20.9% of patients, with an overall mortality of 18.6%. Only four S. mitis revealed penicillin-resistance. Our results are similar to those of other series, identifying these bacteria as emerging pathogens with significant morbidity and mortality in oncologic patients. The MALDI-TOF system increased the rate of viridans group streptococci isolation in this population.

Bloodstream infection caused by S. aureus in patients with cancer: a 10-year longitudinal single-center study.

BACKGROUND: Staphylococcus aureus bloodstream infections (SABIs) represent a significant cause of morbidity and mortality in cancer patients. In this study, we compared infection characteristics and evaluated epidemiology and risk factors associated to SABIs and 30-day attributable mortality in cancer patients. METHODS: Clinical and microbiological data from patients with cancer and positive blood cultures for S. aureus were retrieved during a 10-year period at an oncology reference center. Analyses were performed according to type of malignancy and infection with methicillin-resistant S. aureus (MRSA). Data was evaluated using competing risk analyses to identify risk factors associated to 30-day mortality and used to create a point system for mortality risk stratification. RESULTS: We included 450 patients and MRSA was documented in 21.1%. Hospital-acquired infection, healthcare-associated pneumonia, and type-2 diabetes were associated to MRSA. In patients with hematologic malignancies, MRSA was more frequent if hospital-acquired, but less likely in primary bacteremia. Variables associated to mortality included abdominal source of infection, hematologic malignancy, MRSA, glucose levels > 140 mg/dL, and infectious endocarditis; catheter removal and initiation of adequate treatment within 48 h of positive blood culture were protective factors. From our designed mortality prediction scale, patients with a score > 3 had a 70.23% (95%CI 47.2-85.3%) probability of infection-related death at 30 days. CONCLUSION: SABIs are a significant health burden for cancer patients. Risk factors for SABI-related mortality in this population are varied and impose a challenge for management to improve patient's outcomes. Risk stratification might be useful to evaluate 30-day mortality risk.

[Multidrug resistance E-ESKAPE strains isolated from blood cultures in patients with cancer]. / Cepas E-ESKAPE multidrogorresistentes aisladas en hemocultivos de pacientes con cáncer.

OBJECTIVE: To describe the trend of multidrug resistant (MDR) strains isolated from blood in patients with cancer from 2005 to 2015. MATERIAL AND METHODS: 33 127 blood cultures were processed by retrospective analysis. Identification and antimicrobial sensitivity were performed through automated methods: WaLK away (Siemens Labora- tory Diagnostics) and BD Phoenix (Becton, Dickinson and Company). Resistant strains were determined according to the minimum inhibitory concentration, following the parameters of the Clinical and Laboratory Standards Institute (CLSI). RESULTS: Of 6 397 isolates, 5 604 (16.9%) were positive; 3 732 (58.4%) Gram- bacilli; 2 355 (36.9%) Gram+ cocci; 179 (2.7%) yeasts, and 126 (1.9%) Gram+ bacilli. Escherichia coli (n=1 591, 24.5%) was the most frequent bacteria, with 652 (41%) strains being extended-spectrum beta-lactamases producers (ESBL); of Enterococcus faecium (n=143, 2.1%), 45 (31.5%) were vancomycin resistant; of Staphylococcus aureus (n=571, 8.7%), 121 (21.2%) methicillin resistant (MRSA); of Klebsiella pneumoniae (n=367, 5.6%), 41 (11.2%) ESBL; of Acinetobacter baumanii (n=96, 1.4%), 23 (24%) MDR, and of Pseudomonas aeruginosa (n=384, 5.6%), 43 (11.2%) MDR. MDR strains were significantly more frequent in patients with hematological malignancies, compared to those with solid tumors: MRSA (OR=4.48, 95%CI 2.9-6.8), ESBL E. coli(OR=1.3, 95%CI 1.10-1.65) and MDR Acinetobacter baumanii (OR=3.2, 95%CI 1.2-8.3). CONCLUSIONS: We observed significantly higher isolations of E-ESPAKE MDR strains in patients with hematological malignancies.

OBJETIVO: Describir la tendencia de cepas multidrogorre- sistentes (MDR) aisladas en hemocultivos de pacientes con cáncer durante el periodo de 2005 a 2015. MATERIAL Y MÉTODOS: Análisis retrospectivo en el que se procesaron 33 127 hemocultivos. La identificación y la sensibilidad antimicrobianas se realizaron a través de métodos automatizados WaLK away (Siemens Laboratory Diagnostics) y BD Phoenix (Becton,Dickinson and Company). Se determinaron cepas resistentes de acuerdo con la concentración mínima inhibitoria, según los parámetros del Clinical and Laboratory Standards Institute (CLSI). RESULTADOS: 5 604 (16.9%) aislamientos fueron positivos, con 6 397 aislamientos, 3 732 (58.4%) bacilos gramnegativos,2 355 (36.9%) cocos grampositivos, 179 (2.7%) levaduras y 126 (1.9%) bacilos grampositivos. Escherichia coli (n=1 591,24.5%) fue la bacteria más frecuente, 652 (41%) productoras de beta-lactamasas de espectro-extendido (BLEE); Enterococcus faecium 143 (2.1%), 45 (31.5%) resistente a vancomicina; Staphylococcus aureus 571 (8.7%), 121 (21.2%) resistentes a meticilina (SARM); Klebsiella pneumoniae 367 (5.6%), 41 (11.2%) BLEE, Acinetobacter baumannii 96 (1.4%), 23 (24%) MDR; Pseudomonas aeruginosa 384 (5.6%), 43 (11.2%) MDR. Las cepas MDR se aislaron más frecuentemente en pacientes con neoplasias hematológicas en comparación con tumores sólidos; SARM (RM=4.48, IC95% 2.9-6.8); E. coli BLEE (RM=1.3, IC95% 1.10-1.65) y A. baumannii-MDR (RM=3.2, IC95% 1.2-8.3). CONCLUSIONES: Se observó un aislamiento significativamente mayor de cepas E-ESKAPE MDR en pacientes con neoplasias hematológicas.

Cepas E-ESKAPE multidrogorresistentes aisladas en hemocultivos de pacientes con cáncer / Multidrug resistance E-ESKAPE strains isolated from blood cultures in patients with cancer

Resumen: Objetivo: Describir la tendencia de cepas multidrogorresistentes (MDR) aisladas en hemocultivos de pacientes con cáncer durante el periodo de 2005 a 2015. Material y métodos: Análisis retrospectivo en el que se procesaron 33 127 hemocultivos. La identificación y la sensibilidad antimicrobianas se realizaron a través de métodos automatizados WaLK away (Siemens Laboratory Diagnostics) y BD Phoenix (Becton, Dickinson and Company). Se determinaron cepas resistentes de acuerdo con la concentración mínima inhibitoria, según los parámetros del Clinical and Laboratory Standards Institute (CLSI). Resultados: 5604 (16.9%) aislamientos fueron positivos, con 6397 aislamientos, 3732 (58.4%) bacilos gramnegativos, 2355 (36.9%) cocos grampositivos, 179 (2.7%) levaduras y 126 (1.9%) bacilos grampositivos. Escherichia coli (n=1 591, 24.5%) fue la bacteria más frecuente, 652 (41%) productoras de beta-lactamasas de espectro-extendido (BLEE); Enterococcus faecium 143 (2.1%), 45 (31.5%) resistente a vancomicina; Staphylococcus aureus 571 (8.7%), 121 (21.2%) resistentes a meticilina (SARM); Klebsiella pneumoniae 367 (5.6%), 41 (11.2%) BLEE, Acinetobacter baumannii 96 (1.4%), 23 (24%) MDR; Pseudomonas aeruginosa 384 (5.6%), 43 (11.2%) MDR. Las cepas MDR se aislaron más frecuentemente en pacientes con neoplasias hematológicas en comparación con tumores sólidos; SARM (RM=4.48, IC95% 2.9-6.8); E. coli BLEE (RM=1.3, IC95% 1.10-1.65) y A. baumannii-MDR (RM=3.2, IC95% 1.2-8.3). Conclusiones. Se observó un aislamiento significativamente mayor de cepas E-ESKAPE MDR en pacientes con neoplasias hematológicas.

Abstract: Objective: To describe the trend of multidrug resistant (MDR) strains isolated from blood in patients with cancer from 2005 to 2015. Materials and methods: 33 127 blood cultures were processed by retrospective analysis. Identification and antimicrobial sensitivity were performed through automated methods: WaLK away (Siemens Laboratory Diagnostics) and BD Phoenix (Becton, Dickinson and Company). Resistant strains were determined according to the minimum inhibitory concentration, following the parameters of the Clinical and Laboratory Standards Institute (CLSI). Results: Of 6 397 isolates, 5 604 (16.9%) were positive; 3 732 (58.4%) Gram- bacilli; 2 355 (36.9%) Gram+ cocci; 179 (2.7%) yeasts, and 126 (1.9%) Gram+ bacilli. Escherichia coli (n=1 591, 24.5%) was the most frequent bacteria, with 652 (41%) strains being extended-spectrum beta-lactamases producers (ESBL); of Enterococcus faecium (n=143, 2.1%), 45 (31.5%) were vancomycin resistant; of Staphylococcus aureus (n=571, 8.7%), 121 (21.2%) methicillin resistant (MRSA); of Klebsiella pneumoniae (n=367, 5.6%), 41 (11.2%) ESBL; of Acinetobacter baumanii (n=96, 1.4%), 23 (24%) MDR, and of Pseudomonas aeruginosa (n=384, 5.6%), 43 (11.2%) MDR. MDR strains were significantly more frequent in patients with hematological malignancies, compared to those with solid tumors: MRSA (OR=4.48, 95%CI 2.9-6.8), ESBL E. coli (OR=1.3, 95%CI 1.10-1.65) and MDR Acinetobacter baumanii (OR=3.2, 95%CI 1.2-8.3). Conclusions: We observed significantly higher isolations of E-ESPAKE MDR strains in patients with hematological malignancies.

Stenotrophomonas maltophilia bacteremia and pneumonia at a tertiary-care oncology center: a review of 16 years.

PURPOSE: The aim of this study was to describe the clinical characteristics and antimicrobial patterns of Stenotrophomonas maltophilia bloodstream infections (BSI) and pneumonia episodes in patients with cancer. METHODS: Patients with S. maltophilia BSI or pneumonia admitted from 1 Jan. 2000 to 31 Dec. 2016 were identified at the Instituto Nacional de Cancerología (INCan), a tertiary-care oncology hospital in Mexico City. RESULTS: During the study period, there were 171 isolates identified. The mean age of the whole group was 46.9 ± 17.4 years; 99 (57.9%) were women. There were 95 BSI: 64 ambulatory catheter-related BSI (CRBSI), 20 nosocomial CRBSI, and 11 secondary BSI. Mortality was higher in nosocomial CRBSI (40%) vs. that in ambulatory CRBSI (7.8%) (p = 0.001). There were 76 pneumonia episodes; all were nosocomial acquired; 46 (60.5%) ventilator-associated. From all the group, nine strains (5.2%) were resistant to sulfamethoxazole/trimethoprim/(SMX/TMP). At the first month, 54 patients (31.6%) have died, 38 due to pneumonia (70%) and 16 due to BSI (30%, p < 0.001). Multivariate analysis showed that removal of central venous catheter was associated with a favorable outcome in patients with bacteremia. For patients with pneumonia, age ≥ 65 years and inappropriate antimicrobial treatment were risk factors associated with 30-day mortality. CONCLUSIONS: S. maltophilia related with ambulatory CRBSI have a better prognosis than other sources of BSI. Older patients with pneumonia who do not receive appropriate antibiotics have higher mortality. SMX/TMP is still the antibiotic of choice.

Impact of inappropriate antifungal therapy according to current susceptibility breakpoints on Candida bloodstream infection mortality, a retrospective analysis.

BACKGROUND: The mortality of Candida Bloodstream Infection (CBSI) remains high. Antifungal susceptibility breakpoints were recently updated for Candida species, the impact remains unknown. In this study we evaluated the impact of inappropriate antifungal treatment according to recent breakpoints on 30-day mortality of CBSI. METHODS: From June 2008 to July 2014, data on CBSI episodes from two tertiary-care centers, treated > 72 h were analyzed. Antifungal therapy and 30-day mortality were registered. Inappropriate antifungal treatment according to current Clinical & Laboratory Standards Institute (CLSI) breakpoints was adjusted with 30-day mortality-related co-variates. RESULTS: One hundred forty-nine episodes of CBSI were analyzed. The most frequent species were: C. albicans (40%), C. tropicalis (23%) and C. glabrata complex (20%). According to the 2012 CLSI, 10.7% received inappropriate treatment. The 30-day mortality was 38%; severe sepsis [Odds ratio (OR) 3.4; 95% CI 1.3-8.4], cirrhosis (OR 36; 95% CI 12.2-605), early central venous catheter removal (OR 0.23; 95% CI 0.08-0.66) and previous antifungal therapy (OR 0.15; 95%CI 0.03-0.62), were associated with 30-day mortality by multivariate analysis. Inappropriate antifungal treatment was not (OR 0.19; 95% CI 0.03-1.2). CONCLUSIONS: Appropriate antifungal therapy according to CLSI 2012 did not have an impact on mortality. Mortality of CBSI remains high due to disease severity and comorbidities; early antifungal therapy and catheter removal may reduce it.

[Purple urine bag syndrome: An uncommon manifestation of urinary tract infection]. / Síndrome de la bolsa de orina morada (SBOM): una manifestación infrecuente de infección de vías urinarias (IVU).

CASE REPORT: A 57-year-old paraplegic male diagnosed with non-Hodgkin's lymphoma and complete spinal cord compression arrived at our clinic because of fever and purple discoloration of the urine. We diagnosed purple urine bag syndrome (PUBS) and treated him with oral ciprofloxacin and urinary catheter replacement. DISCUSSION: PUBS is an unusual phenomenon that occurs predominantly in bedridden patients with long-term urinary catheters, presenting as a purple discoloration of the urine bag. Its pathogenesis involves the metabolism of indoxyl sulfate by sulfatase-producing bacteria. Knowledge of this entity is important in order to avoid unnecessary diagnostic workup and treatment.

A polyclonal outbreak of bloodstream infections by Enterococcus faecium in patients with hematologic malignancies.

BACKGROUND: Enterococcus faecium causes bloodstream infection (BSI) in patients with hematologic malignancies (HMs). We studied the clinical features and outcomes of patients with HM with vancomycin-sensitive E faecium (VSE) and vancomycin-resistant E faecium (VRE) BSI and determined the genetic relatedness of isolates and circumstances associated with the upsurge of E faecium BSI. METHODS: Case-control study of patients with HM and E faecium-positive blood culture from January 2008-December 2012; cases were patients with VRE and controls were VSE isolates. The strains were tested for Van genes by polymerase chain reaction amplification and we performed pulsed-field gel electrophoresis to determine genetic relatedness. RESULTS: Fifty-eight episodes of E faecium BSI occurred: 35 sensitive and 23 resistant to vancomycin. Mortality was 46% and 57%, attributable 17% and 40%, respectively. Early stage HM was associated with VSE (P = .044), whereas an episode of BSI within the 3 months before the event (P = .039), prophylactic antibiotics (P = .013), and vancomycin therapy during the previous 3 months (P = .001) was associated with VRE. The VanA gene was identified in 97% of isolates studied. E faecium isolates were not clonal. CONCLUSIONS: E faecium BSI was associated with high mortality. This outbreak of VRE was not clonal; it was associated with antibiotic-use pressure and highly myelosuppressive chemotherapy.