Several studies have demonstrated a diversity of bacterial species in human milk, even in aseptically collected samples. The present study evaluated potential probiotic bacteria isolated from human milk and associated maternal variables. Milk samples were collected from 47 healthy women and cultured on selective and universal agar media under aerobic and anaerobic conditions. Bacterial isolates were counted and identified by Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry and then tested for probiotic properties. Total bacteria in human milk ranged from 1.5 to 4.0 log CFU/mL. The higher bacterial counts were found in colostrum (mean = 3.9 log CFU/mL, 95% CI 3.14-4.22, p = 0.00001). The most abundant species was Staphylococcus epidermidis (n = 76). The potential probiotic candidates were Lactobacillus gasseri (n = 4), Bifidobacterium breve (n = 1), and Streptococcus salivarius (n = 4). Despite the small sample size, L. gasseri was isolated only in breast milk from mothers classified into a normal weight range and after a vaginally delivered partum. No potential probiotics showed antagonism against pathogens, but all of them agglutinated different pathogens. Nine bacterial isolates belonging to the species L. gasseri, B. breve, and S. salivarius were selected as potential probiotics. The present study confirms the presence in breast milk of a bacterial microbiota that could be the source of potential probiotic candidates to be used in the formula of simulated maternal milk.

The carbapenem-hydrolyzing class D ␤-lactamase OXA-253 was identified in an Acinetobacter baumannii clinical isolate belonging to sequence type 113 (ST113) in Brazil. OXA-253 shares 93.8% amino acid identity with OXA-143. The bla OXA-253 gene is located on a ca. 20-kb plasmid. The genetic environment of the bla OXA-253 gene shares the highest identity with ubiquitous GR2 group plasmids usually carrying bla OXA-24/-40 genes.A cinetobacter baumannii strains are frequently associated with nosocomial infections, and their resistance to carbapenems has risen in recent decades (1, 2). The main mechanisms of resistance to carbapenems of A. baumannii are efflux pumps, porin mutations, overexpression of the chromosomally encoded OXA-51-like ␤-lactamase, and the biosynthesis of acquired carbapenem-hydrolyzing class D ␤-lactamases (CHDLs) (oxacillinases) (3). To date, five main groups of CHDLs have been identified in A. baumannii, the intrinsic chromosomally encoded OXA-51-like enzyme and the acquired chromosomally encoded and plasmidencoded OXA-23-like, OXA-40-like, OXA-58-like, and OXA-143-like enzymes (3). OXA-143 was first described in 2009 from an A. baumannii strain isolated in Brazil in 2004 (2). In this study, we report an A. baumannii clinical strain producing OXA-253, a variant of OXA-143. The genetic environment of the plasmidborne bla OXA-253 gene is detailed.The clinical isolate A. baumannii 25 was recovered from a perineal swab in the intensive care unit in Minas Gerais Hospital, Brazil. MICs were determined by Etest (bioMérieux, La Balmeles-Grottes, France). Isolate 25 was resistant to all ␤-lactams, including carbapenems, and had reduced susceptibility to cefepime according to the CLSI guidelines (4) ( Table 1). It was also resistant to fluoroquinolones (ciprofloxacin), and susceptible to aminoglycosides (gentamicin, tobramycin, amikacin, and netilmicin), and tetracycline. A modified version of the CarbaNP test (5) and the CarbAcinetoNP test (P. Nordmann, personal communication) was performed and showed a carbapenemase activity. PCR experiments, performed as previously described for screening of bla , bla , bla OXA-58 and bla OXA-143 genes (6), identified a bla OXA-143 -like gene. Further sequencing of the PCR product identified the bla OXA-253 gene (GenBank number KC479324) and showed 95% nucleotide identity with the bla OXA-143 gene. The deduced protein sequence showed 17 amino acid differences between OXA-143 and OXA-253 (93.8% identity) (Fig. 1). Those amino acid changes do not occur in the conserved residues STFK (position 70 to 73) and KSG (position 216 to 218) of class D ␤-lactamases or in the FGN structural element (position 144 to 146) of carbapenem-hydrolyzing class D ␤-lactamases (CHDLs) (Fig. 1).Plasmid extraction from A. baumannii 25 performed by the Kieser technique yielded two plasmids of ca. 70 and 20 kb (7). The gene encoding the OXA-253 determinant from A. baumannii 25 was transferred to Escherichia coli TOP10 by electroporation. The resulting E. coli TOP10 strain harboring the plasmid o...

Objective:To compare cutaneous and nasal population levels between patients colonized and infected by multidrug-resistant organisms in two intensive care units.Methods:A prospective cohort study was performed in adult intensive care units of two hospitals in Belo Horizonte, Brazil (April 2012 to February 2013). Clinical and demographic data were first collected by reviewing patients’ charts. Then, samples collected with nasal, groin, and perineum swabs were cultivated in selective media for 48 h at 37°C. After isolation, determination of antimicrobial susceptibility and biochemical identification were performed.Results:A total of 53 cases of colonization were observed by the following bacteria in decreasing frequencies: imipenem-resistant Acinetobacter baumannii (50.9%), vancomycin-resistant Enterococcus faecalis (43.4%), extended-spectrum beta-lactamase–producing Klebsiella pneumoniae (37.7%), imipenem-resistant Pseudomonas aeruginosa (32.1%), oxacillin-resistant Staphylococcus aureus (7.5%), and imipenem-resistant Klebsiella pneumoniae (5.7%). Among these colonization cases, 26 (49.0%) were followed by infection with bacteria phenotypically similar to those of the colonization. A relation between high population levels of colonization by most of the multidrug-resistant organisms at anatomical sites and a subsequent infection was observed. After colonization/infection, bacterial population levels decreased progressively and spontaneously until disappearance by day 45 in all the anatomical sites and for all the multidrug-resistant organisms.Conclusion:There was a correlation between high population levels of colonization by multidrug-resistant organisms at anatomical sites and a subsequent infection. Reduction in multidrug-resistant organism populations after colonization at anatomical sites could be a preventive measure to reduce evolution to infection as well as transmission of these bacteria between patients in intensive care unit.

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Background: Recently, the probable involvement of surfaces from the hospital environment as a disseminating source of resistant bacteria has been highlighted. The aim of the study was to compare resistant microorganisms isolated from inanimate surfaces, equipments and patient blood culture samples in an Intensive Care Unit from Belo Horizonte, Brazil. Methods: A cross-sectional study was performed from July to October 2009. Data sources were microbiologic samples from environment and patient blood culture. Duplicate samples were obtained by swabs from up to seven different touch sites around two different patients in four different days. Jointly with the environmental samples, bacterial isolates from an adult ICU patients' routine blood cultures were obtained from hospital laboratory. The samples were identified, tested for sensitivity and compared by rep-PCR test to verify similarity. Results: Difference among the averages of Colony Forming Units was found within the environment samples (p < 0.004). In the environment were identified antibiotic resistant microorganisms such as Vancomycin resistant Enterococcus faecalis, imipenem and ciprofloxacin Pseudomonas aeruginosa and multidrug-resistant Acinetobacter baumannii. Similarities (60%-80%) were established among environmental and blood culture samples. Conclusion: The environmental sampling showed different averages of contamination of the surfaces and equipment. The similarity among the bacterial isolates of patients' blood cultures and environmental samples reinforces the hypothesis of the horizontal transference of pathogens.