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1.
Int J Biol Macromol ; 269(Pt 1): 131881, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38677705

ABSTRACT

This work focuses on the precipitation of lignin from kraft black liquor (BL) along with its valorization into lignin nanoparticles (LNP). Two organic acids namely, acetic acid, and lactic acid were used for the precipitation of lignin as an alternative to sulfuric acid. An optimization study was carried out to determine the effect of three key variables, namely acid type, temperature, and pH, on the isolation yield and purity of lignin. The study showed that all factors primarily influenced the lignin yield, while the purity of precipitated lignin varied only around 1 % between minimum to maximum purity. Further, the acid precipitation method was selected for the preparation of LNP. The study aimed to observe the effect of pH, lignin concentration, and surfactant concentration over the properties of the prepared nanoparticles. The results showed that a smaller nanoparticle size and maximization of phenolic content was achieved with a lignin concentration of 35 mg/mL, a surfactant concentration of 10 % (w/w lignin), and a pH of 5. Additionally, the antibacterial activity of LNPs against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa bacteria was evaluated. The results showed only minor activity against Staphylococcus aureus. Overall, the study demonstrates the potential method for precipitation and valorization of lignin through the production of LNP with desirable properties.


Subject(s)
Chemical Precipitation , Lignin , Nanoparticles , Lignin/chemistry , Nanoparticles/chemistry , Hydrogen-Ion Concentration , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Temperature , Acids/chemistry , Surface-Active Agents/chemistry
2.
Environ Sci Pollut Res Int ; 31(14): 20941-20952, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38381291

ABSTRACT

Zinc and copper have been used as growth promotors in alternative to antibiotics in pig's diet. The aim was the ascertainment of the Zn and Cu concentrations in piglets' liver and kidney and their impact in the reduced susceptibility to Zn, Cu, and antibiotics in enterococci, used as microbiota biomarker. Zn and Cu were determined in the livers and kidneys of 43 piglets slaughtered in Portugal, by flame atomic absorption spectrometry. Enterococci were isolated from feces for determining the identification of species (E. faecalis, E. faecium, and Enterococcus spp.); susceptibility to vancomycin, ciprofloxacin, linezolid, tigecycline, ampicillin, imipenem, and metals; and Cu tolerance genes. In piglets with Zn and Cu high or toxic levels, enterococci had reduced susceptibility to ions, reinforced by the presence of Cu tolerance genes and by resistance to antibiotics. The study relevance is to show the relationship between these metals' levels and decreased susceptibility to Cu, Zn, and antibiotics by enterococci. From the results, it could be supposed that the piglets were being fed with high doses of Zn and Cu which could select more resistant bacteria to both antibiotics and metals that could spread to environment and humans.


Subject(s)
Copper , Enterococcus , Humans , Animals , Swine , Anti-Bacterial Agents/pharmacology , Liver , Kidney , Feces/microbiology , Zinc , Microbial Sensitivity Tests , Enterococcus faecalis/genetics , Drug Resistance, Bacterial
3.
Biol Trace Elem Res ; 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38147233

ABSTRACT

Metal ions such as zinc and copper have been used as alternatives to antibiotics, to improve animal health and growth rates in pig farming. This study aims to determine antibiotic residues and Zn concentration in piglets' livers (n = 56) and kidneys (n = 60); and to examine the correlation between the use of Zn and antibiotics, and resistance to Zn and antibiotics of Escherichia coli isolated from piglets' faeces (n = 60). Samples were collected from randomly selected healthy piglets (n = 60); antibiotic residues were quantified by ultra-high-performance-liquid-chromatography time-of-flight mass spectrometry (UHPLC-ToF-MS); Zn was quantified using flame atomic absorption spectrometry (FAAS); microbiological methods were used for E. coli isolation, antibiotic susceptibility, and Zn minimal inhibitory concentration; and Real-Time PCR was used for gene detection. The presence of antibiotic residues and Zn concentrations in the liver was found to be negatively correlated, whilst no significant difference was observed in the kidney. In E. coli isolated from piglet faeces considered to be susceptible or multi-drug-resistant, no significant difference was found between Zn concentrations in the liver and in the kidney, which appears to indicate that Zn accumulated in the liver and in the kidney does not promote resistance to antibiotics in E. coli. The isolates showed tolerance to Zn which would suggest that antibiotic resistance and phenotypic tolerance to Zn in these isolates are not related. The genes zitB and zntA associated to Zn tolerance, were predominantly found in the more resistant Zn isolates. The findings provide insights on how Zn use in pig production maintains antibiotic resistance and metal tolerance in bacteria, with implications for One Health.

4.
Antioxidants (Basel) ; 12(2)2023 Jan 22.
Article in English | MEDLINE | ID: mdl-36829810

ABSTRACT

Chritmum maritimum, sea fennel, is a facultative halophyte used in salads, soups, and sauces, as well as used to prepare medicinal juices and aqueous extracts (AE) to treat several ailments. Its essential oil (EO) is used as a spice and aromatizing. In this work, the nutritional (crude protein, fiber, lipids, and ashes content) and HPLC-PDA phenolic profiles were determined. Furthermore, the antioxidant potential of the infusion and of the decoction, as well as the antibacterial activity of both, the AE and EO, were assessed against food-contaminating bacteria. The composition of the EO was also established. Sea fennel exhibited considerable fiber (34.3 ± 1.92%) and mineral content (23.6 ± 4.8%). AE contains chlorogenic acid as the major phenolic compound, 49.7 ± 0.8 mg/g in the infusion dry extract and (26.8 ± 0.9 mg/g in the decoction dry extract). EO contains high amounts of monoterpene hydrocarbons, namely γ-terpinene and sabinene. In regards to the antioxidant activity, IC50 values for the infusion and decoction were, respectively: 36.5 ± 1.4 µg/mL and 44.7 ± 4.4 µg/mL in the DPPH assay; 37.3 ± 2.6 µg/mL and 38.4 ± 1.8 µg/mL, in the ABTS assay. EO is particularly active against Bacillus cereus and Lactobacillus plantarum. The results support the use of sea fennel AE and EO as a potential alternative preservative ingredient for feeds, foods, pharmaceutical, and cosmetic industries, due to the antioxidant activity of infusion and decoction, and antibacterial properties of essential oil.

5.
Foods ; 11(8)2022 Apr 16.
Article in English | MEDLINE | ID: mdl-35454745

ABSTRACT

Fresh cheese composition favors the growth of microorganisms and lipid oxidation, leading to a short shelf life. Whey protein concentrates can be used to produce active films in which green tea (Camellia sinensis L.) extract, rich in bioactive compounds, namely catechins, can be incorporated. Thus, the main objective of this study was to evaluate the efficacy of an edible active film, incorporated with green tea extract, to preserve goat and mixture (goat and sheep) fresh cheeses. Our results demonstrated that Portuguese green teas (antioxidant activity coefficient-AAC = 746.7) had superior antioxidant capacity to that of the evaluated Asian green tea (AAC = 650). Furthermore, green tea produced from the leaves of the new Portuguese Chá Camélia tea plantation had the highest potential to retain the antioxidant capacity (97.3%). Additionally, solid-liquid extractions led to extracts with higher antioxidant activity (AAC = 1500), but Soxhlet extractions presented higher yield (43%). Furthermore, the active film incorporated with Portuguese green tea extract exhibited a high antioxidant capacity (AAC ≈ 595.4). In addition, the active film effectively delayed the lipid oxidation of the evaluated fresh cheeses (3.2 mg MDA Eq/kg) when compared with the control (4.2 mg MDA Eq/kg). Moreover, the active films effectively inhibited the growth of microorganisms, especially E. coli (1.5 × 10 CFU/g), when compared with the blank (2.2 × 102 CFU/g). This study suggests that the new whey protein film incorporated with Portuguese green tea extract has the potential to be used to extend fresh cheese shelf life.

6.
J Environ Manage ; 296: 113255, 2021 Oct 15.
Article in English | MEDLINE | ID: mdl-34280837

ABSTRACT

Sewage sludge (SS) is a global environmental, social, and economic problem that requires a sustainable management approach. Still, the production of other industrial wastes, such as lime mud (LM), has recently gained considerable attention to avoid landfilling. This work aims to present a new approach for converting SS and LM into value-added products within the circular economy perspective. In particular, the effect of LM and calcined lime mud (CLM) as drying adjuvants and SS sanitation agents are investigated. Two out of three SS samples show Escherichia coli contamination above the Portuguese limit established for soil application, while no Salmonella spp. was detected in the searched samples. The addition of CLM to SS in a ratio between 0.05 and 0.15 g CLM/gwb, lead to complete elimination of the microbiological contamination in almost all cases. Contrarily, the use of LM does not seem efficient to act as a sanitation agent. Both LM and CLM show a positive impact on the drying process when compared to the raw SS, increasing the drying rate, and reducing the drying time. The most favourable drying conditions to maximize the drying rate and minimize the drying time (until 30% of moisture) are 130 °C, 0.15 g adj/gwb, and 2.5 mm of plate thickness. The thermal treatment (100 and 130 °C) without adjuvants reduces the microbiological contamination below the legal limit. Overall, a beneficial effect is observed by adding CLM to SS, open the possibility of producing a safer organic soil improver.


Subject(s)
Decontamination , Sewage , Calcium Compounds , Oxides
7.
Microb Drug Resist ; 27(12): 1742-1749, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34191606

ABSTRACT

Considering the concept of "One Health," the aim of this study was to determine susceptibility profiles of Escherichia coli in piglets' intestinal microbiota from different farms in Portugal. Beyond antimicrobial susceptibility, the occurrence of multiple antibiotic resistance and detection of phenotypic/genotypic extended-spectrum beta-lactamases (ESBLs) and plasmid mediated AmpC beta-lactamases (pAmpC) were done. From 10 different pig farms, 340 E. coli isolates were obtained from 75 feces samples. Susceptibility to amoxicillin-clavulanic acid (AMC), piperacillin (PIP), cefoxitin (FOX), ceftazidime (CAZ), cefepime (FEP), aztreonam (AZT), imipenem (IP), amikacin (AK), ciprofloxacin (CIP), and trimethoprim-sulfamethoxazole (SXT) was determined. Five-gene panel for amplification of bla genes was used for ESBL (TEM, SHV, CTX-M) and pAmpC (CMY-2, ACC). Among E. coli isolates, 209 were distributed in three resistance profiles: 57.7% MDR, 3.5% extensively drug-resistance (XDR) (resistant to CIP, SXT, and beta-lactams, except IP, with variability to AK) and 0.3% pandrug-resistance (PDR) (resistant to all antibiotics used). pAmpC and/or ESBLs genes were presented in 65% of the isolates. Presence of different associations of bla genes in the same isolate was the most observed (31%), and the most common were an ESBL (TEM) and a pAmpC (CMY-2). Presence of three or four bla genes in various associations were detected. These isolates were very resistant, especially those with four genes, which were resistant to beta-lactams (except IP), CIP, and SXT. This study showed a surprisingly high rate of MDR E. coli isolated in Portuguese piglets, with enzymes that impair activity of the most used antibiotics in human therapeutic.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli/drug effects , Escherichia coli/genetics , Animals , Bacterial Proteins , Feces/microbiology , Gastrointestinal Microbiome , Genes, Bacterial , Microbial Sensitivity Tests , Plasmids , Swine , beta-Lactamases/genetics
8.
Microorganisms ; 8(3)2020 Mar 07.
Article in English | MEDLINE | ID: mdl-32155983

ABSTRACT

This work aims to evaluate the microbiological contamination of sewage sludge (SS) collected in urban wastewater treatment plants (WWTP) from Portugal. Two types of SS were considered: urban mixed (UM) and from anaerobic digestion (AD). The two types of samples were characterized in relation to the main physical and chemical parameters, as well as the microbiological contamination (Escherichia coli and Salmonella spp). Then, sanitation tests were conducted through thermal drying and chemical treatments. Towards a circular economy, industrial alkaline wastes (green liquor dregs - GLD, lime mud, coal fly ash, eggshell) were tested as alternatives to lime. Only six out of nineteen samples complied with the legal limits for both microorganisms. However, drying at 130 °C sanitized selected samples below the E. coli limit, regardless of the initial moisture or contamination. Additionally, CaO (obtained from eggshell) led to the complete elimination of E. coli at any dosage studied (0.05-0.15 g/g SSwet basis). GLD evidenced the ability to reduce E. coli contamination at room temperature, but not enough to comply with the legal limit. In general, this work highlights the need to sanitize the SS before its application to the soil, and the positive role of some wastes on this goal.

9.
BMC Microbiol ; 19(1): 62, 2019 03 19.
Article in English | MEDLINE | ID: mdl-30890149

ABSTRACT

BACKGROUND: Nontuberculous mycobacteria (NTM) are ubiquitous in nature and recognized agents of opportunistic infection, which is often aggravated by their intrinsic resistance to antimicrobials, poorly defined therapeutic strategies and by the lack of new drugs. However, evaluation of their prevalence in anthropogenic environments and the associated antimicrobial resistance profiles have been neglected. In this work, we sought to determine minimal inhibitory concentrations of 25 antimicrobials against 5 NTM isolates recovered from a tertiary-care hospital surfaces. Antimicrobial susceptibilities of 5 other Corynebacterineae isolated from the same hospital were also determined for their potential clinical relevance. RESULTS: Our phylogenetic study with each of the NTM isolates confirm they belong to Mycobacterium obuense, Mycobacterium mucogenicum and Mycobacterium paragordonae species, the latter initially misidentified as strains of M. gordonae, a species frequently isolated from patients with NTM disease in Portugal. In contrast to other strains, the M. obuense and M. mucogenicum examined here were resistant to several of the CLSI-recommended drugs, suggestive of multidrug-resistant profiles. Surprisingly, M. obuense was susceptible to vancomycin. Their genomes were sequenced allowing detection of gene erm (erythromycin resistance methylase) in M. obuense, explaining its resistance to clarithromycin. Remarkably, and unlike other strains of the genus, the Corynebacterium isolates were highly resistant to penicillin, ciprofloxacin and linezolid. CONCLUSIONS: This study highlights the importance of implementing effective measures to screen, accurately identify and control viable NTM and closely related bacteria in hospital settings. Our report on the occurrence of rare NTM species with antibiotic susceptibility profiles that are distinct from those of the corresponding Type strains, along with unexpected resistance mechanisms detected seem to suggest that resistance may be more common than previously thought and also a potential threat to frail and otherwise vulnerable inpatients.


Subject(s)
Anti-Bacterial Agents/pharmacology , Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial , Nontuberculous Mycobacteria/drug effects , Nontuberculous Mycobacteria/isolation & purification , Corynebacterium/drug effects , Equipment and Supplies, Hospital/microbiology , Humans , Microbial Sensitivity Tests , Mycobacterium Infections, Nontuberculous/microbiology , Patients' Rooms , Phylogeny , Portugal , Tertiary Care Centers/statistics & numerical data
10.
J Glob Antimicrob Resist ; 17: 300-304, 2019 06.
Article in English | MEDLINE | ID: mdl-30658199

ABSTRACT

OBJECTIVES: Helicobacter pylori is one of the most prevalent global pathogens colonising an estimated 50% of the world's population. Although metronidazole (MTZ) is an important antibiotic playing a relevant role in various H. pylori eradication therapies, its frequent consumption results in an increased frequency of resistance with a consequent negative impact on treatment efficacy. Mutations on genes encoding NADPH nitroreductases, commonly known as rdxA gene (oxygen-insensitive) and frxA gene (flavinreductase) have been associated to H. pylori resistance to metrodinazole. The aim of this study was to evaluate the mutation profile of rdxA and frxA genes in a population of 38 H. pylori isolates with phenotypic patterns of susceptibility and resistance to this antibiotic. METHODS: Touchdown PCR with the purpose of amplifying rdxA and frxA genes in one PCR was used. Sequence data were made by pair-wise sequence alignment and were examined in terms of codons, and comparison was achieved regarding amino acids. RESULTS: Although repeated mutations occurred in positions 118, 131, 172 and 183 of rdxA and in positions 72, 73, 110, 126 and 193 of frxA, it must be highlighted that the mutations are widespread along these two genes in this population. Furthermore, six MTZ-resistant isolates did not present any mutation in the frxA gene. CONCLUSIONS: This work appears to confirm that mutations in rdxA and frxA alone are unable to explain MTZ resistance in H. pylori isolates and therefore additional mechanisms may exist and should be investigated.


Subject(s)
Bacterial Proteins/genetics , Drug Resistance, Bacterial/genetics , Helicobacter pylori/genetics , Metronidazole/pharmacology , Nitroreductases/genetics , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/drug effects , Helicobacter pylori/drug effects , Humans , Microbial Sensitivity Tests , Mutation , Portugal , Sequence Analysis, Protein
11.
Eur J Pharm Biopharm ; 96: 65-75, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26192459

ABSTRACT

The aim of this work was the development of innovative levofloxacin-loaded swellable microspheres (MS) for the dry aerosol therapy of pulmonary chronicPseudomonas aeruginosainfections in Cystic Fibrosis patients. In a first step, a factorial design was applied to optimize formulations of chitosan-based MS with glutaraldehyde as crosslinker. After optimization, other crosslinkers (genipin, glutaric acid and glyceraldehyde) were tested. Analyses of MS included aerodynamic and swelling properties, morphology, drug loading, thermal and chemical characteristics,in vitroantibacterial activity and drug release studies. The prepared MS presented a drug content ranging from 39.8% to 50.8% of levofloxacin in an amorphous or dispersed state, antibacterial activity and fast release profiles. The highest degree of swelling was obtained for MS crosslinked with glutaric acid and genipin. These formulations also presented satisfactory aerodynamic properties, making them a promising alternative, in dry-powder inhalers, to levofloxacin solution for inhalation.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Chitosan/chemistry , Cross-Linking Reagents/chemistry , Drug Carriers/chemistry , Levofloxacin/administration & dosage , Respiratory Therapy/methods , Technology, Pharmaceutical/methods , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Cystic Fibrosis/drug therapy , Cystic Fibrosis/microbiology , Drug Liberation , Humans , Levofloxacin/chemistry , Levofloxacin/therapeutic use , Microspheres , Particle Size , Powder Diffraction , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Spectroscopy, Fourier Transform Infrared , Surface Properties
13.
BMC Gastroenterol ; 15: 23, 2015 Feb 15.
Article in English | MEDLINE | ID: mdl-25886722

ABSTRACT

BACKGROUND: Empiric triple treatments for Helicobacter pylori (H. pylori) are increasingly unsuccessful. We evaluated factors associated with failure of these treatments in the central region of Portugal. METHODS: This single-center, prospective study included 154 patients with positive (13)C-urea breath test (UBT). Patients with no previous H. pylori treatments (Group A, n = 103) received pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and clarithromycin (CLARI) 500 mg 12/12 h, for 14 days. Patients with previous failed treatments (Group B, n = 51) and no history of levofloxacin (LVX) consumption were prescribed pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and LVX 250 mg 12/12 h, for 10 days. H. pylori eradication was assessed by UBT 6-10 weeks after treatment. Compliance and adverse events were assessed by verbal and written questionnaires. Risk factors for eradication failure were determined by multivariate analysis. RESULTS: Intention-to-treat and per-protocol eradication rates were Group A: 68.9% (95% CI: 59.4-77.1%) and 68.8% (95% CI: 58.9-77.2%); Group B: 52.9% (95% CI: 39.5-66%) and 55.1% (95% CI: 41.3-68.2%), with 43.7% of Group A and 31.4% of Group B reporting adverse events. Main risk factors for failure were H. pylori resistance to CLARI and LVX in Groups A and B, respectively. Another independent risk factor in Group A was history of frequent infections (OR = 4.24; 95% CI 1.04-17.24). For patients with no H. pylori resistance to CLARI, a history of frequent infections (OR = 4.76; 95% CI 1.24-18.27) and active tobacco consumption (OR = 5.25; 95% CI 1.22-22.69) were also associated with eradication failure. CONCLUSIONS: Empiric first and second-line triple treatments have unacceptable eradication rates in the central region of Portugal and cannot be used, according to Maastricht recommendations. Even for cases with no H. pylori resistance to the used antibiotics, results were unacceptable and, at least for CLARI, are influenced by history of frequent infections and tobacco consumption.


Subject(s)
2-Pyridinylmethylsulfinylbenzimidazoles/therapeutic use , Amoxicillin/therapeutic use , Clarithromycin/therapeutic use , Helicobacter Infections/drug therapy , Helicobacter pylori , Levofloxacin/therapeutic use , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Breath Tests , Drug Resistance, Bacterial/genetics , Drug Therapy, Combination/methods , Female , Helicobacter pylori/genetics , Humans , Male , Medication Adherence , Middle Aged , Nitroimidazoles/therapeutic use , Pantoprazole , Portugal , Prospective Studies , Proton Pump Inhibitors/therapeutic use , Treatment Failure , Young Adult
14.
Dig Dis Sci ; 60(1): 74-85, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25142169

ABSTRACT

BACKGROUND: Outcome of Helicobacter pylori (H. pylori) infection results from interaction of multiple variables including host, environmental and bacterial-associated virulence factors. AIM: This study aimed to investigate the correlation of cagA, cagE, vacA, iceA and babA2 genotypes with gastric histopathology and disease phenotype in the central region of a South-European country. METHODS: This prospective study involved 148 infected patients (110 female; mean age 43.5 ± 13.4 years) submitted to endoscopy with corpus and antrum biopsies. H. pylori was cultured and DNA extracted from the isolates. Genotypes were determined by PCR. Histopathological features were graded according to the updated Sydney system and OLGA/OLGIM classification. Only patients with single H. pylori genotypes and complete histopathological results were included. RESULTS: Antrum samples presented higher degrees of atrophy, intestinal metaplasia, chronic inflammation and neutrophil activity. Genotype distribution was as follows: cagA-31.8 %; cagE-45.9 %; vacA s1a-24.3 %; vacA s1b-19.6 %; vacA s1c-0.7 %; vacA s2-55.4 %; vacA m1-20.9 %; vacA m2-79.1 %; vacA s1m1-18.9 %; vacA s1m2-25.7 %; vacA s2m1-2 %; vacA s2m2-53.4 %; iceA1-33.8 %; iceA2-66.2 %; babA2-12.2 %. CagA genotype was significantly associated with higher degrees of intestinal metaplasia, neutrophil activity, chronic inflammation and OLGIM stages. BabA2 was linked with higher H. pylori density. Strains with vacA s1m1 or vacA s1m1 + cagA positive genotypes had a significant association with peptic ulcer and vacA s2m2 with iron-deficient anemia. CONCLUSIONS: cagA, vacA s1m1 and babA2 genotypes are relatively rare in the central region of Portugal. cagA-positive strains are correlated with more severe histopathological modifications. This gene is commonly associated with vacA s1m1, and such isolates are frequently found in patients with peptic ulcer.


Subject(s)
Bacterial Proteins/genetics , Gastritis/microbiology , Helicobacter Infections/genetics , Helicobacter Infections/pathology , Helicobacter pylori/genetics , Adhesins, Bacterial/genetics , Adolescent , Adult , Aged , Antigens, Bacterial/genetics , Female , Gastritis/genetics , Gastritis/pathology , Humans , Male , Middle Aged , Phenotype , Portugal , Prospective Studies , Seroepidemiologic Studies , Stomach/pathology , Virulence , Young Adult
15.
Microb Drug Resist ; 21(2): 194-200, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25372011

ABSTRACT

Multidrug-resistant (MDR) Pseudomonas aeruginosa isolates are increasing worldwide and greatly limit therapeutic options, particularly when considering extensively drug-resistant (XDR) or pandrug-resistant isolates. The resistance profile of P. aeruginosa isolates from a Portuguese central hospital was surveyed during 10 years (n=3,778). About 39.9% were classified as MDR and 2.9% as XDR. Statistical analysis (Mann-Whitney test and regression modeling) revealed a decrease in total MDR rates over time but an increase in XDR rates. This suggests a tendency for higher proportions of XDR isolates in the future, which is of great concern. Isolates of nosocomial origin presented similar results to total population but, when analyzing them according to the different wards of origin, it was still observed a trend of increase in MDR rates in some wards, particularly pneumology, neurology, and neurosurgery. Similar analysis considering the nosocomial specimen source revealed a negative trend of evolution in MDR rates of respiratory origin and a positive trend over time in XDR rates of isolates collected from urine. Regarding the association of antibiotic resistance to MDR and XDR profiles, it was observed a negative relation over time between imipenem resistance and MDR and gentamicin resistance and XDR, suggesting that resistance to these antibiotics may predict the absence of MDR or XDR in P. aeruginosa isolates, respectively. Similar studies in other European hospitals should be performed to give further information to physicians, important for their empirical antibiotherapy regimens.


Subject(s)
Drug Resistance, Multiple, Bacterial/drug effects , Drug Resistance, Multiple, Bacterial/physiology , Pseudomonas aeruginosa/isolation & purification , Adolescent , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Cross Infection/epidemiology , Cross Infection/microbiology , Female , Gentamicins/therapeutic use , Hospitals , Humans , Imipenem/therapeutic use , Male , Middle Aged , Pseudomonas Infections/drug therapy , Pseudomonas aeruginosa/drug effects , Young Adult
16.
Helicobacter ; 19(2): 90-7, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24506175

ABSTRACT

INTRODUCTION: Helicobacter pylori resistance to antibiotics is steadily increasing and multidrug-resistant strains are common and difficult to eliminate, mainly in countries where bismuth, tetracycline, furazolidone, and rifabutin are unavailable. AIM: To evaluate the efficacy and safety of a triple therapy with proton-pump inhibitor (PPI), amoxicillin, and doxycycline in patients with multidrug-resistant H. pylori. PATIENTS AND METHODS: This prospective study involved 16 patients (13 females; mean age - 50 ± 11.3 years) infected by H. pylori with known resistance to clarithromycin, metronidazole, and levofloxacin, but susceptibility to amoxicillin and tetracycline. All patients were previously submitted to upper endoscopy with gastric biopsies for H. pylori culture and susceptibility testing by Etest. Mutations in 23S rRNA and gyrA genes were determined by real-time PCR. A 10-day eradication regimen with PPI (double-standard dose b.i.d.), amoxicillin (1000 mg b.i.d.), and doxycycline (100 mg b.i.d.) was prescribed after pretreatment with PPI during 3 days. Eradication success was assessed by (13) C-urea breath test 6-10 weeks after treatment. Compliance and adverse events were determined through phone contact immediately after treatment and specific written questionnaires. RESULTS: Only one patient did not complete treatment due to adverse events. Another four patients experienced mild side effects not affecting compliance. The control (13) C-urea breath test was positive in all patients. Per-protocol and intention-to-treat eradication rates were 0%. CONCLUSIONS: Although safe, a triple-therapy protocol with high-dose PPI, amoxicillin, and doxycycline is useless for multidrug-resistant H. pylori eradication.


Subject(s)
Amoxicillin/therapeutic use , Anti-Bacterial Agents/therapeutic use , Doxycycline/therapeutic use , Helicobacter Infections/drug therapy , Proton Pump Inhibitors/therapeutic use , Adult , Aged , Amoxicillin/adverse effects , Breath Tests , Clarithromycin/pharmacology , DNA Gyrase/genetics , Disease Eradication/methods , Doxycycline/adverse effects , Drug Resistance, Multiple, Bacterial , Drug Therapy, Combination/adverse effects , Drug Therapy, Combination/methods , Female , Helicobacter pylori/drug effects , Helicobacter pylori/genetics , Humans , Levofloxacin/pharmacology , Male , Metronidazole/pharmacology , Microbial Sensitivity Tests , Middle Aged , Mutation , Prospective Studies , Proton Pump Inhibitors/adverse effects , RNA, Ribosomal, 23S/genetics , Treatment Failure
17.
Microb Drug Resist ; 19(5): 392-6, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23758589

ABSTRACT

Metallo-beta-lactamases (MBLs) can confer broad-spectrum beta-lactam resistance, including carbapenems. The aim of this work was to document the occurrence of MBLs in 122 imipenem-resistant Pseudomonas aeruginosa isolates collected in two Portuguese central hospitals, to determine their antimicrobial susceptibility, and to observe if there were intra- and interhospital epidemic spread. About 20.5% of these isolates presented blaVIM-2, which was found to be widespread in both hospitals. Clonal diversity was observed within hospitals, and no interhospital spread was observed. Ten of the blaVIM-2-positive isolates (44%), from both hospitals, presented one or two class 1 integrons. Two of those contained a VIM-2 gene, one from each hospital, which is indicative for the possibility of MBL gene transfer. No interhospital spread of integrons was observed. Regular screening and surveillance is needed to prevent spread of this worrisome resistance determinant.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Cross Infection/epidemiology , Imipenem/therapeutic use , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/genetics , beta-Lactam Resistance/genetics , beta-Lactamases/genetics , Cross Infection/drug therapy , Cross Infection/microbiology , Gene Transfer, Horizontal , Hospitals, Urban , Humans , Integrons , Microbial Sensitivity Tests , Molecular Epidemiology , Portugal/epidemiology , Prevalence , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/enzymology , Pseudomonas aeruginosa/isolation & purification , beta-Lactam Resistance/drug effects , beta-Lactamases/metabolism
18.
Cad Saude Publica ; 24(6): 1429-38, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18545768

ABSTRACT

This study aimed to determine the prevalence of acute lower respiratory illness and to identify associated factors among children less than five years of age in the city of Rio Grande, southern Brazil. Using a cross-sectional survey, a standardized household questionnaire was applied to mothers or guardians. Information was collected on household conditions, socioeconomic status, and parental smoking. Prenatal care attendance, nutritional status, breastfeeding pattern, and use of health services for the children were also investigated. Data analysis was based on prevalence ratios and logistic regression, using a conceptual framework. Among 771 children studied, 23.9% presented acute lower respiratory illness. The main risk factors were previous episodes of acute lower respiratory infection or wheezing, crowding, maternal schooling less than five years, monthly family income less than US$ 200, four or more people per room, asthma in family members, and maternal smoking. Mothers 30 years or older were identified as a protective factor. These results can help define specific measures to reduce morbidity and mortality due to acute lower respiratory illness in this setting.


Subject(s)
Child Welfare , Health Surveys , Respiratory Tract Infections/epidemiology , Brazil/epidemiology , Child, Preschool , Epidemiologic Methods , Female , Humans , Infant , Infant, Newborn , Male , Maternal Age , Mothers , Prenatal Care , Social Class , Socioeconomic Factors
19.
Cad. saúde pública ; 24(6): 1429-1438, jun. 2008. ilus, tab
Article in English | LILACS | ID: lil-484199

ABSTRACT

This study aimed to determine the prevalence of acute lower respiratory illness and to identify associated factors among children less than five years of age in the city of Rio Grande, southern Brazil. Using a cross-sectional survey, a standardized household questionnaire was applied to mothers or guardians. Information was collected on household conditions, socioeconomic status, and parental smoking. Prenatal care attendance, nutritional status, breastfeeding pattern, and use of health services for the children were also investigated. Data analysis was based on prevalence ratios and logistic regression, using a conceptual framework. Among 771 children studied, 23.9 percent presented acute lower respiratory illness. The main risk factors were previous episodes of acute lower respiratory infection or wheezing, crowding, maternal schooling less than five years, monthly family income less than US$ 200, four or more people per room, asthma in family members, and maternal smoking. Mothers 30 years or older were identified as a protective factor. These results can help define specific measures to reduce morbidity and mortality due to acute lower respiratory illness in this setting.


Este estudo teve por objetivo determinar a prevalência de doenças respiratórias agudas baixas e identificar fatores associados à sua ocorrência entre crianças menores de cinco anos de idade em Rio Grande, Rio Grande do Sul, Brasil. Realizou-se estudo transversal de base populacional com aplicação de questionário em nível domiciliar às mães ou responsáveis pelas crianças. Foram coletadas informações sobre características sócio-econômicas, condições de habitação da família e tabagismo dos pais; sobre as crianças, investigou-se padrão de amamentação e dieta, estado nutricional, assistência à gestação e ao parto e utilização de serviços de saúde. A análise incluiu cálculo das razões de prevalência e regressão logística conforme modelo hierárquico previamente estabelecido. Dentre as 771 crianças estudadas, 23,9 por cento apresentavam doenças respiratórias agudas baixas. Os principais fatores de risco identificados foram antecedente de infecção respiratória, sibilância anterior, aglomeração, escolaridade materna menor que cinco anos, renda familiar menor que dois salários mínimos mensais, quatro ou mais pessoas no quarto da criança, história de asma na família e tabagismo materno. Idade materna igual ou superior a trinta anos mostrou-se protetor. Esses resultados podem contribuir para estabelecer medidas específicas visando a reduzir a morbimortalidade por doenças respiratórias agudas baixas nessa população.


Subject(s)
Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Child Welfare , Health Surveys , Respiratory Tract Infections/epidemiology , Brazil/epidemiology , Epidemiologic Methods , Maternal Age , Mothers , Prenatal Care , Social Class , Socioeconomic Factors
20.
Int J Antimicrob Agents ; 31(4): 375-9, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18276121

ABSTRACT

The increased incidence of Pseudomonas aeruginosa isolated from patients with cystic fibrosis (CF) along with an increase in its multidrug resistance makes therapeutic management very problematic. Careful identification and accurate studies of susceptibility to antibiotics are critical for improving therapeutic measures and for facilitating our understanding of the epidemiology of this pathogen. Fifteen P. aeruginosa isolates obtained from five CF children in the Paediatric Hospital of Coimbra were studied. Isolates from a female patient were resistant to all agents tested except colistin. A VIM-2 enzyme inserted in integron In58 was detected, and this isolate presented a unique random amplified polymorphic DNA (RAPD) type. Others isolates were susceptible to beta-lactams, and each isolate had a different RAPD type. VIM-2 confers resistance to the majority of beta-lactams and is associated with other gene cassettes coding for enzymes that inactivate aminoglycosides. Person-to-person transmission of these isolates is not well understood, therefore it is important to design infection control policies to avoid acquisition and dissemination of multiresistant strains.


Subject(s)
Cystic Fibrosis/microbiology , Pseudomonas aeruginosa/drug effects , beta-Lactamases/metabolism , Adolescent , Child , Child, Preschool , DNA, Bacterial/genetics , Humans , Infant , Microbial Sensitivity Tests , Pseudomonas aeruginosa/enzymology , Reverse Transcriptase Polymerase Chain Reaction , beta-Lactamases/biosynthesis
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