RESUMO
Insoluble phosphorous compounds solubilization by soil bacteria is of great relevance since it puts available the phosphorus to be used by plants. The production of organic acids is the main microbiological mechanism by which insoluble inorganic phosphorus compounds are solubilized. In Gram negative bacteria, gluconic acid is synthesized by the activity of the holoenzyme glucose dehydrogenase-pyrroloquinoline quinine named GDH-PQQ. The use of marker genes is a very useful tool to evaluate the persistence of the introduced bacteria and allow to follow-up the effect of biotic and abiotic factors on these beneficial microorganisms in the soil. In previous studies we detected the presence of the pqqE gene in a great percentage of both non-culturable and culturable native soil bacteria. The objective of this study was to analyze the phylogeny of the sequence of pqqE gene and its potential for the study of phosphate solubilizing bacteria from pure and mixed bacterial cultures and rhizospheric soil samples. For this, the presence of the pqqE gene in the genome of phosphate solubilizing bacteria that belong to several bacteria was determined by PCR. Also, this gene was analyzed from mixed bacterial cultures and rhizospheric soil associated to peanut plants inoculated or not with phosphate solubilizing bacteria. For this, degenerate primers designed from several bacterial genera and specific primers for the genus Pseudomonas spp., designed in this study, were used. DNA template used from simple or mixed bacterial cultures and from rhizospheric soil samples was obtained using two different DNA extraction techniques. Results indicated that pqqE gene amplification product was found in the genome of all Gram negative phosphate solubilizing bacteria analyzed. It was possible to detect this gene in the DNA obtained from mixed cultures where these bacteria grew in interaction with other microorganisms and in that obtained from rhizospheric soil samples inoculated or not with these bacteria. The phylogenetic analysis indicated that pqqE gene is a conserved gene within related genera. In conclusion, pqqE gene could be a potential marker for the study of phosphate solubilizing bacterial populations.
Assuntos
Fosfatos , Filogenia , Microbiologia do Solo , Fosfatos/metabolismo , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Negativas/classificação , Solubilidade , Marcadores Genéticos , Rizosfera , Plantas/microbiologiaRESUMO
Bacterial antibiotic resistance is a public health problem affecting humans and animals. This study focuses on identifying Gram-negative bacilli (GNB) (MALDI-TOF MS and Klebsiella MALDI TypeR) resistant to antimicrobials in freshly emitted feces of healthy captive and rescued wild birds from a zoo in Brazil. Birds from the zoo and rescued from sixteen different orders were investigated. Resistant bacteria from feces were selected (MacConkey agar with 2⯵g/mL cefotaxime). Genomic similarity and plasmid were investigated by Pulsed-Field Gel Electrophoresis of XbaI fragments (XbaI-PFGE) and S1-PFGE. Polymerase Chain Reaction (PCR) was performed to search for beta-lactamase genes. From 80 birds included, 26 from the zoo (50â¯%) and 18 rescued wild birds (64â¯%) presented cefotaxime-resistant GNB. E. coli and Klebsiella spp were the most prevalent species. Among 65 isolates from the zoo and rescued wild birds, 75â¯% were considered multidrug-resistant (MDR). The majority of the isolates were extended-spectrum beta-lactamases (ESBL) producing and resistant to enrofloxacin. blaCTX-M-GROUP-1, blaTEM, and blaSHV were the most detected genes, and blaKPC was detected in K. pneumoniae complex. According to genomic similarity results, some identical profiles were found in birds with no known contact among the zoo or rescued birds. Several isolates carried one to three plasmids (15-350â¯kb). The presence of multidrug-resistant (MDR) isolates from healthy captive and wild birds brings novel data on the dissemination of these elements to the environment.
Assuntos
Animais Selvagens , Antibacterianos , Aves , Fezes , beta-Lactamases , Animais , Brasil/epidemiologia , Aves/microbiologia , Antibacterianos/farmacologia , Fezes/microbiologia , Animais Selvagens/microbiologia , beta-Lactamases/genética , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/classificação , Testes de Sensibilidade Microbiana/veterinária , Farmacorresistência Bacteriana Múltipla/genética , Animais de Zoológico/microbiologia , Plasmídeos/genética , Farmacorresistência Bacteriana/genéticaRESUMO
Prompt and precise identification of carbapenemase-producing organisms is crucial for guiding clinical antibiotic treatments and limiting transmission. Here, we propose modifying the Blue Carba test (BCT) and Carba NP-direct (CNPd) to identify molecular carbapenemase classes, including dual carbapenemase strains, by adding specific Class A and Class B inhibitors. We tested 171 carbapenemase-producing Gram-negative bacilli strains-21 in Class A (KPC, NMC, SME), 58 in Class B (IMP, VIM, NDM, SPM), and 92 with dual carbapenemase production (KPC+NDM, KPC+IMP, KPC+VIM), all previously positive with BCT or CNPd. We also included 13 carbapenemase non-producers. ß-lactamases were previously characterized by PCR. The improved BCT/CNPd methods detect imipenem hydrolysis from an imipenem-cilastatin solution, using pH indicators and Class A (avibactam) and/or Class B (EDTA) inhibitors. Results were interpreted visually based on color changes. CNPd achieved 99.4% sensitivity and 100% specificity in categorizing carbapenemases, while BCT had 91.8% sensitivity and 100% specificity. Performance varied by carbapenemase classes: both tests classified all Class A-producing strains. For Class B, the CNP test identified 57/58 strains (98.3%), whereas the BCT test, 45/58 strains (77.6%), with non-fermenters posing the greatest detection challenge. For Classes A plus B dual producers, both tests performed exceptionally well, with only one indeterminate strain for the BCT. The statistical comparison showed both methods had similar times to a positive result, with differences based on the carbapenemase class or bacterial group involved. This improved assay rapidly distinguishes major Class A or Class B carbapenemase producers among Gram-negative bacilli, including dual-class combinations, in less than 2 hours. IMPORTANCE: Rapid and accurate identification of carbapenemase-producing organisms is of vital importance in guiding appropriate clinical antibiotic treatments and curbing their transmission. The emergence of negative bacilli carrying multiple carbapenemase combinations during and after the severe acute respiratory syndrome coronavirus 2 pandemic has posed a challenge to the conventional biochemical tests typically used to determine the specific carbapenemase type in the isolated strains. Several initiatives have aimed to enhance colorimetric methods, enabling them to independently identify the presence of Class A or Class B carbapenemases. Notably, no previous efforts have been made to distinguish both classes simultaneously. Additionally, these modifications have struggled to differentiate between carriers of multiple carbapenemases, a common occurrence in many Latin American countries. In this study, we introduced specific Class A and Class B carbapenemase inhibitors into the Blue Carba test (BCT) and Carba NP-direct (CNP) colorimetric assays to identify the type of carbapenemase, even in cases of multiple carbapenemase producers within these classes. These updated assays demonstrated exceptional sensitivity and specificity (≥ 90%) all within a rapid turnaround time of under 2 hours, typically completed in just 45 minutes. These in-house enhancements to the BCT and CNP assays present a rapid, straightforward, and cost-effective approach to determining the primary carbapenemase classes. They could serve as a viable alternative to molecular biology or immuno-chromatography techniques, acting as an initial diagnostic step in the process.
Assuntos
Antibacterianos , Proteínas de Bactérias , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , beta-Lactamases , beta-Lactamases/análise , beta-Lactamases/metabolismo , Proteínas de Bactérias/metabolismo , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/classificação , Humanos , Antibacterianos/farmacologia , Sensibilidade e Especificidade , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/diagnóstico , Imipenem/farmacologiaRESUMO
In this study, the genetic differences and clinical impact of the carbapenemase-encoding genes among the community and healthcare-acquired infections were assessed. This retrospective, multicenter cohort study was conducted in Colombia and included patients infected with carbapenem-resistant Gram-negative rods between 2017 and 2021. Carbapenem resistance was identified by Vitek, and carbapenemase-encoding genes were identified by whole-genome sequencing (WGS) to classify the alleles and sequence types (STs). Descriptive statistics were used to determine the association of any pathogen or gene with clinical outcomes. A total of 248 patients were included, of which only 0.8% (2/248) had community-acquired infections. Regarding the identified bacteria, the most prevalent pathogens were Pseudomonas aeruginosa and Klebsiella pneumoniae. In the WGS analysis, 228 isolates passed all the quality criteria and were analyzed. The principal carbapenemase-encoding gene was blaKPC, specifically blaKPC-2 [38.6% (88/228)] and blaKPC-3 [36.4% (83/228)]. These were frequently detected in co-concurrence with blaVIM-2 and blaNDM-1 in healthcare-acquired infections. Notably, the only identified allele among community-acquired infections was blaKPC-3 [50.0% (1/2)]. In reference to the STs, 78 were identified, of which Pseudomonas aeruginosa ST111 was mainly related to blaKPC-3. Klebsiella pneumoniae ST512, ST258, ST14, and ST1082 were exclusively associated with blaKPC-3. Finally, no particular carbapenemase-encoding gene was associated with worse clinical outcomes. The most identified genes in carbapenemase-producing Gram-negative rods were blaKPC-2 and blaKPC-3, both related to gene co-occurrence and diverse STs in the healthcare environment. Patients had several systemic complications and poor clinical outcomes that were not associated with a particular gene.IMPORTANCEAntimicrobial resistance is a pandemic and a worldwide public health problem, especially carbapenem resistance in low- and middle-income countries. Limited data regarding the molecular characteristics and clinical outcomes of patients infected with these bacteria are available. Thus, our study described the carbapenemase-encoding genes among community- and healthcare-acquired infections. Notably, the co-occurrence of carbapenemase-encoding genes was frequently identified. We also found 78 distinct sequence types, of which two were novel Pseudomonas aeruginosa, which could represent challenges in treating these infections. Our study shows that in low and middle-income countries, such as Colombia, the burden of carbapenem resistance in Gram-negative rods is a concern for public health, and regardless of the allele, these infections are associated with poor clinical outcomes. Thus, studies assessing local epidemiology, prevention strategies (including trials), and underpinning genetic mechanisms are urgently needed, especially in low and middle-income countries.
Assuntos
Antibacterianos , Proteínas de Bactérias , Bactérias Gram-Negativas , Infecções por Bactérias Gram-Negativas , Pseudomonas aeruginosa , beta-Lactamases , Humanos , Colômbia/epidemiologia , beta-Lactamases/genética , beta-Lactamases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estudos Retrospectivos , Masculino , Feminino , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Pessoa de Meia-Idade , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/classificação , Antibacterianos/farmacologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/enzimologia , Adulto , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Idoso , Infecção Hospitalar/microbiologia , Infecção Hospitalar/epidemiologia , Carbapenêmicos/farmacologia , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/epidemiologia , Sequenciamento Completo do Genoma , Adolescente , Adulto JovemRESUMO
BACKGROUND: Aquatic matrices impacted by sewage may shelter carbapenem-resistant (CR) Gram-negative bacilli (GNB) harboring resistance genes of public health concern. In this study, sewage treatment plants (STPs) servicing well-defined catchment areas were surveyed for the presence of CR-GNB bearing carbapenemase genes (blaKPC or blaNDM). RESULTS: A total of 325 CR-GNB were recovered from raw (RS) and treated (TS) sewage samples as well as from water body spots upstream (UW) and downstream (DW) from STPs. Klebsiella-Enterobacter (KE) group amounted to 116 isolates (35.7%). CR-KE isolates were recovered from TS, DW (35.7%) and RS samples (44.2%) (p = 0.001); but not from UW samples. KE isolates represented 65.8% of all blaKPC or blaNDM positive strains. The frequency of blaKPC-or-NDM strains was positively associated with the occurrence of district hospitals located near STPs, as well as with the number of hospitalizations and of sewer connections serviced by the STPs. blaKPC-or-NDM strains were recovered from ST samples in 7 out of 14 STPs, including four tertiary-level STPs; and from 6 out of 13 DW spots whose RS samples also had blaKPC-or-NDM strains. CONCLUSIONS: Clinically relevant GNB bearing blaKPC-or-NDM resist sewage treatments and spread into environmental aquatic matrices mainly from STPs impacted by hospital activities.
Assuntos
Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana/genética , Bactérias Gram-Negativas/isolamento & purificação , Hospitais de Distrito , Microbiologia da Água , beta-Lactamases/genética , Brasil , Área Programática de Saúde , Farmacorresistência Bacteriana/efeitos dos fármacos , Monitoramento Ambiental , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/microbiologia , Hospitalização , Humanos , Esgotos/microbiologia , Purificação da ÁguaRESUMO
Due to their phylogenetic proximity to humans, nonhuman primates (NHPs) are considered an adequate choice for a basic and preclinical model of sepsis. Gram-negative bacteria are the primary causative of sepsis. During infection, bacteria continuously release the potent toxin lipopolysaccharide (LPS) into the bloodstream, which triggers an uncontrolled systemic inflammatory response leading to death. Our previous research has demonstrated in vitro and in vivo using a mouse model of septic shock that Fh15, a recombinant variant of the Fasciola hepatica fatty acid binding protein, acts as an antagonist of Toll-like receptor 4 (TLR4) suppressing the LPS-induced proinflammatory cytokine storm. The present communication is a proof-of concept study aimed to demonstrate that a low-dose of Fh15 suppresses the cytokine storm and other inflammatory markers during the early phase of sepsis induced in rhesus macaques by intravenous (i.v.) infusion with lethal doses of live Escherichia coli. Fh15 was administered as an isotonic infusion 30 min prior to the bacterial infusion. Among the novel findings reported in this communication, Fh15 (i) significantly prevented bacteremia, suppressed LPS levels in plasma, and the production of C-reactive protein and procalcitonin, which are key signatures of inflammation and bacterial infection, respectively; (ii) reduced the production of proinflammatory cytokines; and (iii) increased innate immune cell populations in blood, which suggests a role in promoting a prolonged steady state in rhesus macaques even in the presence of inflammatory stimuli. This report is the first to demonstrate that a F. hepatica-derived molecule possesses potential as an anti-inflammatory drug against sepsis in an NHP model. IMPORTANCE Sepsis caused by Gram-negative bacteria affects 1.7 million adults annually in the United States and is one of the most important causes of death at intensive care units. Although the effective use of antibiotics has resulted in improved prognosis of sepsis, the pathological and deathly effects have been attributed to the persistent inflammatory cascade. There is a present need to develop anti-inflammatory agents that can suppress or neutralize the inflammatory responses and prevent the lethal consequences of sepsis. We demonstrated here that a small molecule of 14.5 kDa can suppress the bacteremia, endotoxemia, and many other inflammatory markers in an acute Gram-negative sepsis rhesus macaque model. These results reinforce the notion that Fh15 constitutes an excellent candidate for drug development against sepsis.
Assuntos
Anti-Inflamatórios/administração & dosagem , Bacteriemia/tratamento farmacológico , Fasciola hepatica/metabolismo , Proteínas de Ligação a Ácido Graxo/administração & dosagem , Bactérias Gram-Negativas/fisiologia , Proteínas de Helminto/administração & dosagem , Animais , Anti-Inflamatórios/metabolismo , Bacteriemia/genética , Bacteriemia/imunologia , Bacteriemia/microbiologia , Citocinas/genética , Citocinas/imunologia , Modelos Animais de Doenças , Fasciola hepatica/química , Fasciola hepatica/genética , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Humanos , Macaca mulatta , Masculino , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologiaRESUMO
In this Research Communication we evaluate the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify 380 bacteria isolated from cases of bovine mastitis in Brazil. MALDI-TOF MS identifications were compared to previous identifications by biochemical tests and 16S rRNA sequencing. MALDI-TOF MS achieved a typeability of 95.5%. The accuracy of MALDI-TOF MS for the identification of Staphylococcus isolates was 93.2%. The agreement between MALDI-TOF MS and biochemical identification of Streptococcus agalactiae was 96%, however, the agreement between these techniques for identifying other catalase-negative, Gram-positive cocci was lower. Agreement in identifying Gram-negative bacteria at the genus level was 90.5%. Our findings corroborate that MALDI-TOF MS is an accurate, rapid and simple technique for identifying bovine mastitis pathogens. The availability of this methodology in some research institutions would represent a significant step toward increasing the diagnosis and epidemiological studies of bovine mastitis and other animal infectious diseases in Brazil.
Assuntos
Mastite Bovina/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/veterinária , Animais , Brasil , Bovinos , Feminino , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/genética , Leite/microbiologia , RNA Ribossômico 16S/genética , Sensibilidade e Especificidade , Análise de Sequência de RNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Staphylococcus/genética , Streptococcus agalactiae/genéticaRESUMO
Introduction. Bloodstream infection is one of the most frequent and challenging hospital-acquired infections and it is associated with high morbidity, mortality and additional use of healthcare resources.Hypothesis/Gap Statement: Bloodstream infections have consequences for the patient, such as the evolution to mortality and inappropriate empirical antibiotic prescription, especially when caused by multidrug-resistant Gram-negative bacilli.Objective. To assess the impact of bloodstream infection and the status of multidrug resistance (MDR) in the evolution of patients who received inappropriate initial antibiotic therapy.Methods. A retrospective surveillance was conducted on nosocomial bloodstream infections caused by Gram-negative bacilli (GNB) from January 2012 to December 2018 in an adult intensive care unit of a Brazilian tertiary teaching hospital.Results. We identified 270 patients with GNB nosocomial bacteremia. Non-survivors were older (with an average age of 58.8 years vs 46.9 years, P=<0.0001), presented more severe illnesses, were immunosuppressed (73.7 vs 37.6%, P=<0.0001), were more likely to have septic shock (55.8 vs 22.4%, P=<0.0001) and had an increased usage of mechanical ventilators (98.6 vs 89.6%, P=0.0013) than survivors. In a logistic regression model, inappropriate empirical antibiotic therapy was not an independent predictor of mortality, different from mechanical ventilator (P=<0.0001; OR=28.0; 95% CI=6.3-123.6), septic shock (P=0.0051; OR=2.5; 95% CI=1.3-4.9) and immunosuppression (P=0.0066; OR=2.6; 95% CI=1.3-5.2). In contrast, in a separate model, MDR was strongly associated with the prescription of inappropriate initial antibiotic therapy (P=0.0030; OR=5.3; 95% CI=1.7-16.1). The main isolated pathogens were Acinetobacter baumannii (23.6â%) and Klebsiella pneumoniae (18.7â%). The frequency of MDR organisms was high (63.7â%), especially among non-fermenting bacilli (60.9â%), highlighting A. baumannii (81.6â%) and Pseudomonas aeruginosa (41.8â%).Conclusion. Illness severity (septic shock and immunosuppression) and mechanical ventilation were identified as predictors of mortality. Additionally, MDR was a major determinant of inappropriate antibiotic empirical therapy, but not associated with mortality, and both characteristics were not statistically associated with death.
Assuntos
Bacteriemia/microbiologia , Infecção Hospitalar/microbiologia , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Bacteriemia/mortalidade , Brasil , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/mortalidade , Farmacorresistência Bacteriana Múltipla , Feminino , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/mortalidade , Hospitais de Ensino/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Centros de Atenção Terciária/estatística & dados numéricos , Adulto JovemRESUMO
To assess the performance of the drop test for polymyxin B resistance detection among Enterobacterales and non-fermentative gram-negative rods resistant to carbapenems. Seven hundred and fifteen carbapenem-resistant isolates were tested: 628 Enterobacterales species and 87 non-fermentative gram-negative rods. For the polymyxin drop test, concentrations range from 0.25 to 8.0 µg/mL. Broth microdilution, as gold standard, was performed using in-house-prepared panels and interpreted according to the CLSI guidelines. Results were interpreted in terms of categorical agreements and discrepancies. Accuracy for a drop of polymyxin B at 2.0, 4.0 and 8.0 was calculated as better cutoff for resistance determination. No very major error was observed among all isolates, and 95.5% of agreement was observed among Enterobacterales, particularly for Klebsiella pneumoniae. A higher accuracy (95.1%) was obtained when a single drop of polymyxin B at 4.0 µg/mL was applied. Polymyxin drop test presented >95% of categorical agreement, without very major errors, for KPC-producing K. pneumoniae isolates. An accuracy of 95.1% was obtained with a single drop at 4.0 µg/mL polymyxin B. Polymyxin B drop is an easy and feasible test and may allow a reduction on the turnaround time for polymyxin resistance detection and impacting on early implementation of accurate therapeutic interventions.
Assuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/microbiologia , Polimixina B/farmacologia , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/classificação , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/isolamento & purificação , Humanos , Testes de Sensibilidade MicrobianaRESUMO
INTRODUCTION: The mother plays a fundamental role in the constitution and regulation of her child's healthy microbiota, however, preterm newborns are separated from their mothers soon after birth and transferred to Neonatal Intensive Care Units, being exposed the constant risk for the development of multidrug-resistant microorganisms' infections. The aim of this study was to explore the multidrug-resistant microorganism colonization of hospitalized babies and their mothers in the neonatal unit context. METHODOLOGY: A prospective case study conducted with hospitalized babies and their mothers in the Neonatal Unit at a university hospital. The sample was composed of 433 binomials (mother-child). Colonization culture samples were taken at the moment of the baby's discharge, via two swabs in the oral, nasal, axillary, inguinal, and rectal regions. RESULTS: The colonization incidence among the binomials, 30 (6.9%) were both colonized by multi-resistant microorganisms. Mothers of colonized babies (24.4%) demonstrated a higher chance of colonization in comparison to mothers of non-colonized babies (11.9%) (p = 0.002). Relationships were drawn between baby colonization and prematurity, extremely low birth weight, and non-exclusive maternal breastfeeding (p<0.05). ESBL-producing Gram-negative microorganisms were more frequent in the cultures of the binomials, with 35.9% of the babies colonized with Klebsiella spp. ESBL and 42.0% of the mothers with Escherichia coli ESBL. Furthermore, 50% of the binomials were colonized with E. coli ESBL. CONCLUSION: The prematurity, extremely low birth weight, and non-exclusive breastfeeding at hospital discharge were associated with baby colonization by multidrug-resistant microorganism. Furthermore, mothers of colonized children presented higher chances of colonization.