Performance of two methods of carbapenem-resistant Enterobacterales surveillance on a kidney transplant ward: selective culture of and real-time PCR directly from rectal swabs.

BACKGROUND: Infection with carbapenem-resistant Enterobacterales (CRE) is associated with a high mortality rate in kidney transplant recipients, and colonization with CRE is one of the major risk factors for CRE infection. There is, therefore, a need to improve the capacity to detect colonization with CRE among inpatients. METHODS: In this prospective study, we compared the performance of real-time PCR for carbapenemase directly from rectal swabs with that of conventional CRE surveillance culture in all patients admitted to a kidney transplant ward between February 2019 and March 2020. Surveillance culture and real-time PCR were performed at admission and weekly until hospital discharge. Two perineum-rectal swabs were collected: one for culture and one for PCR. RESULTS: We collected 905 paired samples for CRE surveillance from 399 patients, of whom 347 (87.0%) were kidney transplant recipients and 52 were waiting list patients. CRE was detected by culture and/or PCR in 75 patients (18.8%). Positivity for CRE was identified by PCR in 62 (15.5%) of the 399 patients and by culture in 55 (13.8%); 20 (5.0%) of the patients tested positive only on PCR, and 13 (3.3%) tested positive only on culture. The most common carbapenemase and species were, respectively, blaKPC (in 85.5%) and Klebsiella pneumoniae (in 80.0%). Infection with CRE occurred in 21.6% of the colonized patients, those cases occurred only among kidney transplant recipients. None of the patients who tested negative on culture developed CRE infection. CONCLUSION: In conclusion, the two methods are complementary and could be useful in a scenario of high CRE prevalence.

The role of therapy with aminoglycoside in the outcomes of kidney transplant recipients infected with polymyxin- and carbapenem-resistant Enterobacteriaceae.

Kidney transplant recipients are at risk for infections due to carbapenem-resistant Enterobacteriaceae (CRE). Polymyxin-resistant CRE (PR-CRE) infections are especially difficult to treat. The aim of this study was to characterize PR-CRE infections among kidney transplant recipients and identify risk factors for treatment failure. This retrospective cohort study involved all kidney transplant recipients with PR-CRE infection between 2013 and 2017 at our center. Minimal inhibitory concentrations for polymyxin B were determined by broth microdilution. Carbapenem-resistant genes (blaKPC, blaNDM, and blaOXA-48), aminoglycoside-resistance genes, and polymyxin-resistant gene mcr-1 were identified by polymerase chain reaction. All but one of the 47PR-CRE infections identified were due to Klebsiella pneumoniae. The most common type of infection (in 54.3%) was urinary tract infection (UTI). Monotherapy was used in 10 cases. Combined treatment regimens included double-carbapenem therapy in 19 cases, oral fosfomycin in 19, and amikacin in 13. Treatment failure occurred in 21 cases (45.7%). Clinical success was achieved 78.9% of patients who used aminoglycosides versus 37.0% of those who not used this drug (p = 0.007). Multivariate analysis showed diabetes mellitus to be a risk factor for treatment failure; amikacin use and UTI were found to be protective. Nine strains were RmtB producers. Although aminoglycosides constitute an important therapeutic option for PR-CRE infection, the emergence of aminoglycoside resistance could have a major impact on the management of CRE infection.

Outbreak of IMP-producing carbapenem-resistant Enterobacter gergoviae among kidney transplant recipients.

OBJECTIVES: The objective of this study was to investigate a prolonged outbreak of carbapenem-resistant Enterobacter gergoviae (CREG) involving kidney transplant recipients (KTRs) between 2009 and 2014. METHODS: A case-control study was undertaken. Controls (n = 52) were selected from CREG-negative KTRs. Surveillance cultures for CREG were collected weekly. Colonization was defined as isolation of CREG from surveillance samples or from clinical specimens, with no evidence of infection. We also investigated infection control practices at the facility. RESULTS: Of 26 identified cases, 13 had had no known contact with another CREG-positive patient before the first positive culture. Seven patients (27%) developed infection. The site most often colonized was the urinary tract. During the study period two clusters were identified, one in 2009 and another in 2013-14. DNA sequencing revealed blaIMP-1 in all CREG tested. No environmental or hand cultures tested positive for CREG. An audit of infection control practices detected flaws in the handling and cleaning of urinary tract devices. Multivariate analysis identified advanced age, ureteral stent use, retransplantation and male gender as risk factors for CREG acquisition. CONCLUSIONS: An outbreak among KTRs caused by an unusual species of MDR bacteria may have resulted from a common source of contamination related to urinary tract devices.

Impact of an Antimicrobial Stewardship Program Intervention Associated with the Rapid Identification of Microorganisms by MALDI-TOF and Detection of Resistance Genes in ICU Patients with Gram-Negative Bacteremia.

Combination of strategies for rapid diagnostics tests (RDT) with real-time intervention could improve patient outcomes. We aimed to assess the impact on clinical outcomes, antimicrobial consumption, and costs in patients with gram-negative bacteremia. We designed a quasi-experimental study among 216 episodes of gram-negative bacteremia using RDT (MALDI-TOF and detection of resistance genes) directly from blood culture bottles combined with real-time communication of results. Our study did not demonstrate impact on 30-day mortality (25% vs. 35%; p = 0.115). Hospital and ICU length of stay were significantly lower in the intervention period ((44 days vs. 39 days; p = 0.005) and (17 days vs. 13 days; p = 0.033)), respectively. The antimicrobial consumption was 1381 DOT/1000 days in the pre-intervention period compared to 1262 DOT/1000 days in the intervention period (p = 0.032). Antimicrobials against gram-positive and carbapenems had a significantly reduced consumption in the intervention period. Our intervention showed no impact on 30 days-mortality, but demonstrated an impact on hospital and ICU length of stay, as well as antimicrobials consumption and costs. Knowledge of resistance genes adds value and information for safe decision making that can result in direct and indirect benefits related to the economic burden of antibiotic overuse and bacterial resistance.

Genomic Characterization of mcr-1.1-Producing Escherichia coli Recovered From Human Infections in São Paulo, Brazil.

Polymyxins are one of most important antibiotics available for multidrug-resistant Gram-negative infections. Diverse chromosomal resistance mechanisms have been described, but the polymyxin resistance phenotype is not yet completely understood. The objective of this study was to characterize colistin resistant mcr-1-producing strains isolated from human infections over one year in a hospital setting (Hospital das Clínicas, São Paulo, Brazil). We isolated 490 colistin-resistant Gram-negative rods, of which eight were mcr-1.1-positive Escherichia coli, the only species with this result, indicating a low incidence of the mcr-1 production mechanism among colistin-resistant isolates. All mcr-1.1 positive isolates showed similarly low MICs for colistin and were susceptible to most antibiotics tested. The isolates showed diversity of MLST classification. The eight mcr-1.1-positive E. coli genomes were sequenced. In seven of eight isolates the mcr-1.1 gene is located in a contig that is presumed to be a part of an IncX4 plasmid; in one isolate, it is located in a contig that is presumed to be part of an IncHI2A plasmid. Three different genomic contexts for mcr-1.1 were observed, including a genomic cassette mcr-1.1-pap2 disrupting a DUF2806 domain-containing gene in six isolates. In addition, an IS1-family transposase was found inserted next to the mcr-1.1 cassette in one isolate. An mcr-1.1-pap2 genomic cassette not disrupting any gene was identified in another isolate. Our results suggest that plasmid dissemination of hospital-resident strains took place during the study period and highlight the need for continued genomic surveillance.

KPC-producing Enterobacterales with uncommon carbapenem susceptibility profile in Vitek 2 system.

KPC-producing K. pneumoniae is an endemic challenge. Seven KPC-producing Enterobacterales showed unusual carbapenems susceptibility profile. These strains were resistance at least one carbapenem and the ertapenem MIC was lower than imipenem and/or meropenem MICs using Vitek 2™ system (bioMerieux). When E-test™ and disk diffusion methods were performed the carbapenems showed susceptible results.

Diagnostic performance of the Xpert Carba-R™ assay directly from rectal swabs for active surveillance of carbapenemase-producing organisms in the largest Brazilian University Hospital.

BACKGROUND: The global spread of carbapenemase-producing organisms (CPO) has been considered by international health authorities as a critical public health concern. Brazil has a high CPO prevalence according to distinct publications but many routine microbiology laboratories have only phenotypic resources to evaluate this epidemiological situation, which is time-consuming and detects only carbapenem-resistant isolates missing CPO susceptible expressing a slightly decreased susceptibility. New molecular platforms can detect CPO faster but a local evaluation is essential. AIM: To evaluate the performance of CPO detection direct from rectal swabs with the Xpert Carba-R™ assay (Cepheid, Sunnyvale, CA) in the largest Brazilian University Hospital. METHODS: A prospective diagnostic accuracy study of CPO was performed with the collection of rectal swabs from patients admitted into the Intensive Care Unit (ICU) and into the Emergency Department (ED) between April and July 2016. The Xpert Carba-R™ assay results were compared with carbapenem-resistant Enterobacterales (CRE) surveillance cultures plus in-house PCR carbapenemase detection (reference method). In case of discordant results between methods, additional tests were performed. The limit of detection (LoD) for the CRE culture and the Xpert Carba-R™ assay were performed with contrived isolates of known carbapenemases genes. RESULTS: A total of 921 clinical rectal swabs were analyzed being 21% (196/921) from the ICU and 79% (725/921) from the ED. Overall, the Xpert Carba-R™ assay detected 9.9% (91/921) of CPOs being 9.5% (87/921) positive only for blaKPC and 0.4% (4/921) positive only for blaNDM. The reference method detected 9.1% (84/921) CPO being 77 (8.4%) blaKPC, 5 blaVIM (0.5%) and 2 blaNDM (0.2%). No IMP or OXA-48 like gene was detected. Overall, twelve samples, 1.3% (10 blaKPC, 2 blaNDM) were Xpert Carba-R™ positive but negative by the reference method. Five isolates (0.5%) were positive for blaVIM only by in-house PCR and confirmed to be blaVIM-2 by DNA sequencing. The Kappa value, sensitivity, specificity, positive/negative predictive values and accuracy of the Xpert Carba-R™ assay were; 0.893 (95% confidence interval [CI], 0.842-0.944), 94% (86.7-98.0), 98.6% (97.5-99.3), 86.8% (78.1-93.0), 99.4% (98.6-99.8) and 98.2% (97.3-99.1), respectively. The LoD for blaKPC of the Xpert Carba-R™ assay and the CRE cultures were 101 CFU/swab. CONCLUSION: The Xpert Carba-R™ assay is an accurate test to detect CPO directly from the rectal swabs with significant lower turnaround time (TAT) when compared to the reference method (CRE culture plus in-house PCR). Xpert Carba-R™ may, therefore, be regarded as a good and fast epidemiological tool.

Capnocytophaga sputigena bloodstream infection in hematopoietic stem cell transplantations: two cases report and review of the literature.

Capnocytophaga is a group of facultative anaerobic gram-negative bacteria present in the oral cavity of humans, dogs and cats, as part of their normal oral flora. Here, we described two cases of bloodstream infections (BSI) caused by Capnocytophaga in neutropenic autologous hematopoietic stem cell transplantation (auto-HSCT) patients with mucositis (Grade I and Grade III) identified by Maldi-Tof. They were successfully treated with ß-lactam (meropenem and piperacillin-tazobactam). The species C. sputigena was confirmed by 16S rRNA gene sequencing in one patient. The review of literature showed that C. ochraceae was the most frequent species causing BSI in auto-HSCT patients and that the patients usually presented mucositis and were neutropenic at the onset of the infection.

Multidrug-resistant Klebsiella pneumoniae: genetic diversity, mechanisms of resistance to polymyxins and clinical outcomes in a tertiary teaching hospital in Brazil.

Increased resistance to polymyxin in Klebsiella pneumoniae (ColRKP) has been observed. Molecular epidemiology, as well as the clinical impact of these difficult to treat pathogens need to be better characterized. We present the clinical outcomes of 28 patients infected by ColRKP in a tertiary hospital. Isolates with MIC >2 by Vitek 2 were confirmed by the microdilution broth test. Polymerase chain reaction (PCR) was performed for blaKPC, blaNDM, blaOXA-48 and blamcr-1 genes in the isolates, and Whole Genome Sequencing (WGS) was performed in six isolates. Seventeen (61%) patients were female and the mean age was 50 years old. In-hospital and 30-day mortality were 64% (18/28) and 53% (15/28), respectively. Central line-associated bloodstream infection in addition to bacteremia episodes due to other sources were the most frequent (61%). Mean APACHE and Charlson comorbidity index were 16 and 5, respectively. Twenty patients (71%) received at least one active drug and ten (35%) received two drugs: tigecycline 46% (13/28); amikacin 21% (6/28) and fosfomycin 3% (1 case). Twenty-six out of 28 tested cases were positive for blaKPC. Eight different clusters were identified. Four STs were detected (ST11, ST23, ST340, and ST437). Mutations on pmrA, arnB, udg, and yciM genes were present in all six isolates submitted to WGS; lpxMand mgrB mutations were also detected in all but one isolate. In conclusion, we observed resistance to polymyxin in severely ill patients mostly from intensive care units and/or immunosuppressed patients with high mortality rates in whom a diversity of ColRKP clusters was identified and might indicate selective pressure.

Emergence of colistin resistance in the largest university hospital complex of São Paulo, Brazil, over five years.

Colistin resistance involving Gram-negative bacilli infections is a challenge for health institutions around of the world. Carbapenem-resistance among these isolates makes colistin the last therapeutic option for this treatment. Colistin resistance among Enterobacteriaceae, Acinetobacter spp., and Pseudomonas spp. was evaluated between 2010 and 2014 years, at Hospital das Clínicas, São Paulo, Brazil. Over five years 1346 (4.0%) colistin resistant Gram-negative bacilli were evaluated. Enterobacteriaceae was the most frequent (86.1%) pathogen isolated, followed by Acinetobacter spp. (7.6%), and Pseudomonas spp. (6.3%). By temporal analysis there was a trend for an increase of colistin resistance among Enterobacteriaceae, but not among non-fermentative isolates. Among 1346 colistin resistant isolates, carbapenem susceptibility was observed in 21.5%. Colistin resistance in our hospital has been alarmingly increased among Klebsiella pneumoniae isolates in both KPC positive and negative, thus becoming a therapeutic problem.

Plasmid-mediated mcr-1 in carbapenem-susceptible Escherichia coli ST156 causing a blood infection: an unnoticeable spread of colistin resistance in Brazil?

OBJECTIVE: We describe an IncX4 pHC891/16mcr plasmid carrying mcr-1 in a colistin-resistant and carbapenem-susceptible E. coli isolate (HC891/16), ST156, which caused a blood infection in a Brazilian patient with gallbladder adenocarcinoma. METHODS: Strain HC891/16 was subjected to whole genome sequencing using the MiSeq Platform (Illumina, Inc., USA). Assembly was performed using Mira and ABACAS. RESULTS: The isolates showed resistance only to ciprofloxacin, ampicillin and cefoxitin, and whole-genome sequencing revealed the presence of aac(6')Ib-cr and blaTEM1. CONCLUSION: Our findings warn of the possible silent dissemination of colistin resistance by carbapenem-susceptible mcr-1 producers, as colistin susceptibility is commonly tested only among carbapenem-resistant isolates.

The modified Hodge test is a useful tool for ruling out Klebsiella pneumoniae carbapenemase.

OBJECTIVE: Enterobacteriaceae bacteria harboring Klebsiella pneumoniae carbapenemase are a serious worldwide threat. The molecular identification of these pathogens is not routine in Brazilian hospitals, and a rapid phenotypic screening test is desirable. This study aims to evaluate the modified Hodge test as a phenotypic screening test for Klebsiella pneumoniae carbapenemase. METHOD: From April 2009 to July 2011, all Enterobacteriaceae bacteria that were not susceptible to ertapenem according to Vitek2 analysis were analyzed with the modified Hodge test. All positive isolates and a random subset of negative isolates were also assayed for the presence of blaKPC. Isolates that were positive in modified Hodge tests were sub-classified as true-positives (E. coli touched the ertapenem disk) or inconclusive (distortion of the inhibition zone of E. coli, but growth did not reach the ertapenem disk). Negative results were defined as samples with no distortion of the inhibition zone around the ertapenem disk. RESULTS: Among the 1521 isolates of Enterobacteriaceae bacteria that were not susceptible to ertapenem, 30% were positive for blaKPC, and 35% were positive according to the modified Hodge test (81% specificity). Under the proposed sub-classification, true positives showed a 98% agreement with the blaKPC results. The negative predictive value of the modified Hodge test for detection was 100%. KPC producers showed high antimicrobial resistance rates, but 90% and 77% of these isolates were susceptible to aminoglycoside and tigecycline, respectively. CONCLUSION: Standardizing the modified Hodge test interpretation may improve the specificity of KPC detection. In this study, negative test results ruled out 100% of the isolates harboring Klebsiella pneumoniae carbapenemase 2. The test may therefore be regarded as a good epidemiological tool.

Emergence of colistin resistance in the largest university hospital complex of São Paulo, Brazil, over five years

Abstract Colistin resistance involving Gram-negative bacilli infections is a challenge for health institutions around of the world. Carbapenem-resistance among these isolates makes colistin the last therapeutic option for this treatment. Colistin resistance among Enterobacteriaceae, Acinetobacter spp., and Pseudomonas spp. was evaluated between 2010 and 2014 years, at Hospital das Clínicas, São Paulo, Brazil. Over five years 1346 (4.0%) colistin resistant Gram-negative bacilli were evaluated. Enterobacteriaceae was the most frequent (86.1%) pathogen isolated, followed by Acinetobacter spp. (7.6%), and Pseudomonas spp. (6.3%). By temporal analysis there was a trend for an increase of colistin resistance among Enterobacteriaceae, but not among non-fermentative isolates. Among 1346 colistin resistant isolates, carbapenem susceptibility was observed in 21.5%. Colistin resistance in our hospital has been alarmingly increased among Klebsiella pneumoniae isolates in both KPC positive and negative, thus becoming a therapeutic problem.

Plasmid-mediated mcr-1 in carbapenem-susceptible Escherichia coli ST156 causing a blood infection: an unnoticeable spread of colistin resistance in Brazil?

OBJECTIVE: We describe an IncX4 pHC891/16mcr plasmid carrying mcr-1 in a colistin-resistant and carbapenem-susceptible E. coli isolate (HC891/16), ST156, which caused a blood infection in a Brazilian patient with gallbladder adenocarcinoma. METHODS: Strain HC891/16 was subjected to whole genome sequencing using the MiSeq Platform (Illumina, Inc., USA). Assembly was performed using Mira and ABACAS. RESULTS: The isolates showed resistance only to ciprofloxacin, ampicillin and cefoxitin, and whole-genome sequencing revealed the presence of aac(6')Ib-cr and blaTEM1. CONCLUSION: Our findings warn of the possible silent dissemination of colistin resistance by carbapenem-susceptible mcr-1 producers, as colistin susceptibility is commonly tested only among carbapenem-resistant isolates.

The modified Hodge test is a useful tool for ruling out Klebsiella pneumoniae carbapenemase

OBJECTIVE: Enterobacteriaceae bacteria harboring Klebsiella pneumoniae carbapenemase are a serious worldwide threat. The molecular identification of these pathogens is not routine in Brazilian hospitals, and a rapid phenotypic screening test is desirable. This study aims to evaluate the modified Hodge test as a phenotypic screening test for Klebsiella pneumoniae carbapenemase. METHOD: From April 2009 to July 2011, all Enterobacteriaceae bacteria that were not susceptible to ertapenem according to Vitek2 analysis were analyzed with the modified Hodge test. All positive isolates and a random subset of negative isolates were also assayed for the presence of blaKPC. Isolates that were positive in modified Hodge tests were sub-classified as true-positives (E. coli touched the ertapenem disk) or inconclusive (distortion of the inhibition zone of E. coli, but growth did not reach the ertapenem disk). Negative results were defined as samples with no distortion of the inhibition zone around the ertapenem disk. RESULTS: Among the 1521 isolates of Enterobacteriaceae bacteria that were not susceptible to ertapenem, 30% were positive for blaKPC, and 35% were positive according to the modified Hodge test (81% specificity). Under the proposed sub-classification, true positives showed a 98% agreement with the blaKPC results. The negative predictive value of the modified Hodge test for detection was 100%. KPC producers showed high antimicrobial resistance rates, but 90% and 77% of these isolates were susceptible to aminoglycoside and tigecycline, respectively. CONCLUSION: Standardizing the modified Hodge test interpretation may improve the specificity of KPC detection. In this study, negative test results ruled out 100% of the isolates harboring Klebsiella pneumoniae carbapenemase 2. The test may therefore be regarded as a good epidemiological tool.

O uso de plantas nativas de cerrados da regiäo de Bauru, na medicina popular - o pequi (Caryocar brasiliensi Camb.) / The use for native plants of \"cerrados in the region of Bauru in popular medicine - the souari nut (Caryocar brasiliense Camb.)

Dentro do Projeto Medicina Popular, lançado pela Fundaçäo Projeto Rondon em 1985, desenvolveu-se juntamente com a Universidade do Sagrado Coraçäo um trabalho visando extrair o máximo de informaçöes sobre as propriedades farmacológicas e nutricionais das espécies nativas existentes nos cerrados do município de Bauru - SP. Esta primeira comunicaçäo, além da apresentaçäo do programa, inclui também os primeiros resultados do programa, inclui também os primeiros resultados da pesquisa bibliográfica feita com o pequi (Caryocar brasiliense Camb.)