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1.
BMC Microbiol ; 24(1): 312, 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39182027

RESUMO

BACKGROUND: More than a century has passed since it was discovered that many bacteria produce indole, but research into the actual biological roles of this molecule is just now beginning. The influence of indole on bacterial virulence was extensively investigated in indole-producing bacteria like Escherichia coli. To gain a deeper comprehension of its functional role, this study investigated how indole at concentrations of 0.5-1.0 mM found in the supernatant of Escherichia coli stationary phase culture was able to alter the virulence of non-indole-producing bacteria, such as Pseudomonas aeruginosa, Proteus mirabilis, and Klebsiella pneumoniae, which are naturally exposed to indole in mixed infections with Escherichia coli. RESULTS: Biofilm formation, antimicrobial susceptibility, and efflux pump activity were the three phenotypic tests that were assessed. Indole was found to influence antibiotic susceptibly of Pseudomonas aeruginosa, Proteus mirabilis and Klebsiella pneumoniae to ciprofloxacin, imipenem, ceftriaxone, ceftazidime, and amikacin through significant reduction in MIC with fold change ranged from 4 to 16. Biofilm production was partially abrogated in both 32/45 Pseudomonas aeruginosa and all eight Proteus mirabilis, while induced biofilm production was observed in 30/40 Klebsiella pneumoniae. Moreover, acrAB and oqxAB, which encode four genes responsible for resistance-nodulation-division multidrug efflux pumps in five isolates of Klebsiella pneumoniae were investigated genotypically using quantitative real-time (qRT)-PCR. This revealed that all four genes exhibited reduced expression indicated by 2^-ΔΔCT < 1 in indole-treated isolates compared to control group. CONCLUSION: The outcomes of qRT-PCR investigation of efflux pump expression have established a novel clear correlation of the molecular mechanism that lies beneath the influence of indole on bacterial antibiotic tolerance. This research provides novel perspectives on the various mechanisms and diverse biological functions of indole signaling and how it impacts the pathogenicity of non-indole-producing bacteria.


Assuntos
Antibacterianos , Biofilmes , Escherichia coli , Indóis , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/metabolismo , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Indóis/metabolismo , Indóis/farmacologia , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Antibacterianos/farmacologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Regulação para Baixo , Proteus mirabilis/genética , Proteus mirabilis/efeitos dos fármacos , Proteus mirabilis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Virulência/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo
2.
Virol J ; 21(1): 130, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38840177

RESUMO

BACKGROUND: Limited data is available regarding the severity and mortality of Mpox in individuals with immunocompromised conditions. Therefore, we performed this meta-analysis to understand the impact of HIV- or non-HIV-associated immunosuppression on the severity of Mpox requiring hospitalization and mortality. METHODS: A thorough literature search was performed from 2022 up to January 2024. The results were presented as odds ratios (ORs). We only included patients who required hospitalization for severity rather than isolation. RESULTS: A total of 34 studies were included in this analysis. Our analysis did not find a significant difference in the hospitalization risk between HIV-positive individuals and those who were HIV-negative (OR = 1.03; P = 0.85; 7 studies; CD4 count of fewer than 200 cells/µL was less than 0.5% across all studies). Patients with a CD4 count lower than 200 cells/µL or an unsuppressed RNA viral load (> 200 copies/ml) had a significantly higher hospitalization risk (OR = 5.3, P < 0.001) and (OR = 3, P < 0.001), respectively. Most of the reported deaths were reported in patients with HIV with CD4 counts below 200 cells/µL, with some fatal cases occurring in non-HIV immunosuppressed patients, particularly organ transplant recipients. Based on the autopsy findings, Mpox was confirmed in multiple organs, particularly the digestive tract, lung, and testes. Furthermore, some studies documented cases of death that were suspected to be related to hemophagocytic lymphohistiocytosis (HLH) and immune reconstitution inflammatory syndrome (IRIS). Most of the death reports showed concomitant non-Mpox infections at the time of hospitalization and death CONCLUSIONS: Our finding shows that Mpox acts as an opportunistic pathogen in immunocompromised individuals. These individuals should be prioritized for early care and closely monitored for signs of deteriorating clinical conditions. Clinical manifestations and autopsy findings strongly suggest Mpox dissemination to multiple organs, particularly the digestive tract, and lungs. However, the presence of concomitant non-Mpox infections complicates the assessment of the attribution of Mpox to death. Caution should be exercised when interpreting data suggesting poorer outcomes in individuals with non-HIV immunosuppression, as current evidence is scarce and further research is needed.


Assuntos
Infecções por HIV , Hospitalização , Hospedeiro Imunocomprometido , Mpox , Humanos , Hospitalização/estatística & dados numéricos , Infecções por HIV/mortalidade , Infecções por HIV/complicações , Infecções por HIV/imunologia , Contagem de Linfócito CD4 , Mpox/epidemiologia , Mpox/mortalidade , Surtos de Doenças , Terapia de Imunossupressão/efeitos adversos , Carga Viral
3.
Cureus ; 16(1): e51838, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38327928

RESUMO

BACKGROUND:  Community-acquired urinary tract infection (UTI) is one of the most common infectious diseases nowadays. Alarming increased levels of antimicrobial resistance are developing globally which limit treatment options and may lead to life-threatening problems. AIM: Our study aimed to collect surveillance data on non-hospitalized Egyptian UTI cases and to develop strategies against multidrug-resistant pathogens (MDR). According to our knowledge, this is the first study to screen this high number (15,252 urine samples) in a short period (three months), providing valuable data on resistance profiles in non-hospitalized Egyptian UTI patients. METHODS: A total of 15,252 urine samples were collected from different patients. Positive cultures were identified using a semi-quantitative method. Kirby-Bauer's disc diffusion method was used for antibiotic susceptibility testing, the double disc diffusion method was used for extended-spectrum beta-lactamases-producing strains, and the Chi-square test was used for statistical data processing. RESULTS: The results showed 61% positive cultures, females accounted for 67.5%. Infants and elderly patients showed the highest positive cultures (74.4% and 69.2%, respectively). Despite Escherichia coli being the most common uropathogen (47.19%), Klebsiella species(24.42%) were the most MDR and extended-spectrum ß-lactamase (ESBL)-producing organisms. E. coli and Klebsiella spp. displayed increased resistance to cephalosporins (75% and 81%, respectively). In contrast, both organisms displayed high sensitivity to carbapenems. Unlike Klebsiella spp., E. coli was highly sensitive (92%) to first-line treatment (nitrofurantoin) for UTI. Moreover, trimethoprim/sulfamethoxazole showed higher sensitivity rates compared to other nations. CONCLUSION:  Despite Escherichia coli being the most often identified bacteria in our isolates Klebsiella spp. displayed higher resistance to the majority of tested antibiotics. Fortunately, trimethoprim/sulfamethoxazole significantly increased sensitivity, especially against E. coli. However, both species showed high rates of cephalosporin resistance. Moreover, It is important to promote Egypt's national action plan for antimicrobial resistance in collaboration with the World Health Organization, especially in the community to minimize the chance of bacterial resistance in the Egyptian community.

4.
Braz J Microbiol ; 55(1): 297-308, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37979131

RESUMO

The exposure of bacteria to sub-inhibitory concentrations of antibiotics is of biological significance since it can occur in vivo under many circumstances, including low-dose treatment, poor adherence to a regimen, poor drug penetration, drug-drug interactions, and antibiotic resistance of the pathogen. In this study, we investigated the effects of subinhibitory concentrations of four antibiotics: ampicillin, ceftriaxone, gentamicin, and norfloxacin, which are commonly used in clinical settings and on cell morphology and biofilm formation in Staphylococcus aureus as one of the leading causes of nosocomial and biofilm-associated infections. Nine clinical S. aureus biofilm-producing isolates and two known biofilm-producing reference strains, S. aureus ATCC 29213 and S. aureus ATCC 6538, were used in this study. Sub-MICs of beta-lactam antibiotics (ampicillin and ceftriaxone) significantly induced biofilm formation in S. aureus ATCC 29213 and S. aureus ATCC 6538 and in six clinical isolates out of the nine selected isolates when compared with the antibiotic-free control group (P < 0.05), with an approximately 2- to 2.5-fold increase. Gentamicin and norfloxacin induced biofilms in S. aureus ATCC 29213 and S. aureus ATCC 6538, while gentamicin and norfloxacin induced biofilms only in three and two of the nine tested isolates, respectively (P < 0.05). The chemical nature of the biofilm matrix produced by half the MIC of ceftriaxone in the six isolates that showed increased biofilm was all non-polysaccharide in composition (PIA-independent). Gene expression of biofilm-encoding genes atl and sarA in biofilms of the two tested strains (S. aureus ATCC 6538) and clinical strain (S. aureus 16) showed a significant upregulation after exposure to half MIC of ceftriaxone. Additionally, the bacterial cell morphological changes in planktonic cells caused by half MIC of ceftriaxone were evaluated by scanning electron microscopy, which demonstrated a significant cell enlargement when compared with the antibiotic-free control (P < 0.05), and some deformed cells were also noticed. In S. aureus clinical isolates, sub-MICs of ampicillin, ceftriaxone, gentamicin, and norfloxacin may stimulate substantial production of biofilm, which could have important clinical significance and make infection treatment challenges. Further, in vivo research is needed to fully comprehend how sub-MIC of antibiotics can affect biofilm formation in clinical settings. Additionally, more research is required to reveal the clinical implications of the morphological alterations in S. aureus brought on by exposure to ceftriaxone at concentrations below its MIC.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Ceftriaxona/farmacologia , Norfloxacino/farmacologia , Antibacterianos/farmacologia , Infecções Estafilocócicas/microbiologia , Ampicilina/farmacologia , Gentamicinas/farmacologia , Biofilmes , Testes de Sensibilidade Microbiana
5.
Infect Drug Resist ; 15: 3459-3475, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35813084

RESUMO

Background: Fungi are rich source of biologically active metabolites aimed for the improvement of human health through the prevention of various diseases, including infections and inflammatory disorders. Aim: We aimed to in vitro examine the anti-SARS CoV-2 activity of the aqueous extract of each Pleurotus (P.) ostreatus, Lentinula (L.) edodes and Agaricus (A.) bisporus edible mushroom followed by docking analysis of certain metabolites against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-main protease (protease Mpro). Methods: Antiviral and cytotoxic effects were tested on hCoV-19/Egypt/NRC-3/2020/Vero-E6 cells and analyzed via (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide Assay (MTT) assay. Ligand-protein and protein-protein docking studies were performed to explore the interaction of different mushroom extracts at the binding site of protease Mpro. Molecular dynamics (MD) simulations were performed on the most promising ligand-target complexes to investigate their dynamic properties and confirm docking results. Results: Substantial antiviral activities with an IC50 of 39.19, 26.17, and 10.3.3 µg/mL and a selectivity index (SI) of 4.34, 3.44, and 1.5 for P. ostreatus, L. edodes and A. bisporus, were observed, respectively. Docking analysis revealed that, catechin from three mushroom isolates, chlorogenic acid from A. bisporus, kamperferol of P. ostreatus and quercetin from L. edodes, with a C-DOCKER interaction energy in the range of 22.8-37.61 (Kcal/mol) with protease compared to boceprevir ligand of 41.6 (Kcal/mol). Docking of superoxide dismutase, catalase from the three mushrooms, tyrosinase from A. bisporus showed ligand contact surface area with the protein as 252.74 Å2 while receptor contact surface area was 267.23 Å2. Conclusion: P. ostreatus, L. edodes and A. bisporus have potential and remarkable in vitro antiviral activities against SARS-CoV-2. Quercetin from L. edodes, Kaempferol from P. ostreatus, chlorogenic acid and ascorbic acid, catechin, superoxide dismutase and catalase of the three mushrooms extracts were effectively bounded to Mpro of SARS-CoV-2 as conferred by docking analysis.

6.
Sci Rep ; 12(1): 12423, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35859110

RESUMO

Mushrooms are nutritious foods that are widely cultivated all over the world. They are rich in a range of compounds linked to improving functions of the immune system including carotenoids, alkaloids, lectins, enzymes, folates, fats, organic acids, minerals, polysaccharides, phenolics, proteins, tocopherols, terpenoids, and volatile compounds. In this study we investigated, the immunomodulatory activity in rats of the aqueous extracts of five of the most common edible mushrooms belonging to Family Basidiomycota-white-rot fungi including, Lentinula edodes, Agaricus bisporus, Pleurotus ostreatus, Pleurotus columbinus, and Pleurotus sajor-caju. Male Wistar albino rats were assigned to thirteen groups and Immunosuppression was induced by oral administration of dexamethasone (0.1 mg/kg), followed by oral administration of the mushroom extracts at low (200 mg/kg) and high (400 mg/kg) doses. A positive control group received the immune stimulant Echinacea extract Immulant® at (30 mg/kg), while the negative control group received only saline. From each animal, in each group, blood samples were collected after 15 days for complete blood counts and for measurement of immunologic parameters, including lysozyme activity, nitric oxide (NO) production and serum cytokines including tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ) and interleukin 1 beta (IL-1ß) levels. Results have shown that white blood cells (WBCs) and lymphocytic counts were significantly boosted by high doses of each of the five mushroom extracts (207-289% increase for WBC and 153-175% for lymphocytes) with a significant increase in lysozyme activity (110-136% increase), NO concentration (159-232% increase) and cytokines as compared to the negative control group. Histopathological examination of the rats' spleen and thymus tissues has shown marked lymphocytic proliferation that was more obvious at the higher doses. In conclusion, our results showed that the five edible mushroom extracts revealed significant immunostimulatory effects preclinically particularly, at the higher doses (400 mg/kg) which can be considered the effective dose.


Assuntos
Agaricus , Muramidase , Animais , Citocinas , Echinacea , Masculino , Extratos Vegetais , Ratos , Ratos Wistar
7.
Molecules ; 26(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34361776

RESUMO

In this study, we examined aqueous extracts of the edible mushrooms Pleurotus ostreatus (oyster mushroom) and Lentinula edodes (shiitake mushroom). Proteome analysis was conducted using LC-Triple TOF-MS and showed the expression of 753 proteins by Pleurotus ostreatus, and 432 proteins by Lentinula edodes. Bioactive peptides: Rab GDP dissociation inhibitor, superoxide dismutase, thioredoxin reductase, serine proteinase and lectin, were identified in both mushrooms. The extracts also included promising bioactive compounds including phenolics, flavonoids, vitamins and amino acids. The extracts showed promising antiviral activities, with a selectivity index (SI) of 4.5 for Pleurotus ostreatus against adenovirus (Ad7), and a slight activity for Lentinula edodes against herpes simplex-II (HSV-2). The extracts were not cytotoxic to normal human peripheral blood mononuclear cells (PBMCs). On the contrary, they showed moderate cytotoxicity against various cancer cell lines. Additionally, antioxidant activity was assessed using DPPH radical scavenging, ABTS radical cation scavenging and ORAC assays. The two extracts showed potential antioxidant activities, with the maximum activity seen for Pleurotus ostreatus (IC50 µg/mL) = 39.46 ± 1.27 for DPPH; 11.22 ± 1.81 for ABTS; and 21.40 ± 2.20 for ORAC assays. This study encourages the use of these mushrooms in medicine in the light of their low cytotoxicity on normal PBMCs vis à vis their antiviral, antitumor and antioxidant capabilities.


Assuntos
Antineoplásicos/química , Antioxidantes/química , Antivirais/química , Proteínas Fúngicas/química , Pleurotus/química , Proteoma/química , Cogumelos Shiitake/química , Aminoácidos/química , Aminoácidos/isolamento & purificação , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Antivirais/isolamento & purificação , Antivirais/farmacologia , Benzotiazóis/antagonistas & inibidores , Compostos de Bifenilo/antagonistas & inibidores , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Misturas Complexas/química , Flavonoides/química , Flavonoides/isolamento & purificação , Proteínas Fúngicas/classificação , Proteínas Fúngicas/isolamento & purificação , Humanos , Lectinas/química , Lectinas/isolamento & purificação , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Especificidade de Órgãos , Fenóis/química , Fenóis/isolamento & purificação , Picratos/antagonistas & inibidores , Pleurotus/metabolismo , Cultura Primária de Células , Proteoma/classificação , Proteoma/isolamento & purificação , Serina Proteases/química , Serina Proteases/isolamento & purificação , Cogumelos Shiitake/metabolismo , Ácidos Sulfônicos/antagonistas & inibidores , Superóxido Dismutase/química , Superóxido Dismutase/isolamento & purificação , Tiorredoxina Dissulfeto Redutase/química , Tiorredoxina Dissulfeto Redutase/isolamento & purificação , Vitaminas/química , Vitaminas/isolamento & purificação , Água/química
8.
J Fungi (Basel) ; 7(8)2021 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-34436184

RESUMO

In this study, we investigated aqueous extracts of three edible mushrooms: Agaricus bisporus (white button mushroom), Pleurotus columbinus (oyster mushroom), and Pleurotus sajor-caju (grey oyster mushroom). The extracts were biochemically characterized for total carbohydrate, phenolic, flavonoid, vitamin, and protein contents besides amino acid analysis. Triple TOF proteome analysis showed 30.1% similarity between proteomes of the two Pleurotus spp. All three extracts showed promising antiviral activities. While Pleurotus columbinus extract showed potent activity against adenovirus (Ad7, selectivity index (SI) = 4.2), Agaricus bisporus showed strong activity against herpes simplex II (HSV-2; SI = 3.7). The extracts showed low cytotoxicity against normal human peripheral blood mononuclear cells (PBMCs) and moderate cytotoxicity against prostate (PC3, DU-145); colorectal (Colo-205); cecum carcinoma (LS-513); liver carcinoma (HepG2); cervical cancer (HeLa); breast adenocarcinoma (MDA-MB-231 and MCF-7) as well as leukemia (CCRF-CEM); acute monocytic leukemia (THP1); acute promyelocytic leukemia (NB4); and lymphoma (U937) cell lines. Antioxidant activity was evaluated using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging, 2,2'-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid) ABTS radical cation scavenging, and oxygen radical absorbance capacity (ORAC) assays. The three extracts showed potential antioxidant activities with the maximum activity recorded for Pleurotus columbinus (IC50 µg/mL) = 35.13 ± 3.27 for DPPH, 13.97 ± 4.91 for ABTS, and 29.42 ± 3.21 for ORAC assays.

9.
FEMS Microbiol Lett ; 368(4)2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33580963

RESUMO

Staphylococcus aureus and Cutibacterium acnes are involved in several tissue infections and can encounter mesenchymal stem cells (MSCs) during their role in tissue regenerative process. C. acnes and S. aureus internalization by three types of MSCs derived from bone marrow, dental pulp and Wharton's jelly; and bacterial biofilm production were compared. Internalization rates ranged between 1.7-6.3% and 0.8-2.7% for C. acnes and S. aureus, respectively. While C. acnes strains exhibited limited cytotoxic effect on MSCs, S. aureus were more virulent with marked effect starting after only 3 h of interaction. Both bacteria were able to produce biofilms with respectively aggregated and monolayered structures for C. acnes and S. aureus. The increase in C. acnes capacity to develop biofilm following MSCs' internalization was not linked to the significant increase in number of live bacteria, except for bone marrow-MSCs/C. acnes CIP 53.117 with 79% live bacteria compared to the 36% before internalization. On the other hand, internalization of S. aureus had no impact on its ability to form biofilms composed mainly of living bacteria. The present study underlined the complexity of MSCs-bacteria cross-interaction and brought insights into understanding the MSCs behavior in response to bacterial infection in tissue regeneration context.


Assuntos
Células-Tronco Mesenquimais/microbiologia , Propionibacterium acnes/fisiologia , Staphylococcus aureus/fisiologia , Biofilmes/crescimento & desenvolvimento , Sobrevivência Celular , Citoplasma/microbiologia , Interações Hospedeiro-Patógeno , Humanos , Infecções Relacionadas à Prótese/microbiologia
10.
Microorganisms ; 8(9)2020 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-32932750

RESUMO

Cutibacterium acnes is an opportunistic pathogen involved in Bone and Prosthesis Infections (BPIs). In this study, we observed the behavior of commensal and BPI C. acnes strains in the bone environment through bacterial internalization by osteoblast-like cells and biofilm formation. For the commensal strains, less than 1% of the bacteria were internalized; among them, about 32.7 ± 3.9% persisted intracellularly for up to 48 h. C. acnes infection seems to have no cytotoxic effect on bone cells as detected by LDH assay. Interestingly, commensal C. acnes showed a significant increase in biofilm formation after osteoblast-like internalization for 50% of the strains (2.8-fold increase). This phenomenon is exacerbated on a titanium support, a material used for medical devices. For the BPI clinical strains, we did not notice any increase in biofilm formation after internalization despite a similar internalization rate by the osteoblast-like cells. Furthermore, fluorescent staining revealed more live bacteria within the biofilm after osteoblast-like cell interaction, for all strains (BPIs and commensal). The genomic study did not reveal any link between their clinical origin and phylotype. In conclusion, we have shown for the first time the possible influence of internalization by osteoblast-like cells on commensal C. acnes.

11.
Biomed Res Int ; 2019: 6736897, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467906

RESUMO

The aim of this study was to investigate the mechanisms responsible for resistance to antimicrobials in a collection of enterobacterial isolates recovered from two hospitals in Saudi Arabia. A total of six strains isolated from different patients showing high resistance to carbapenems was recovered in 2015 from two different hospitals, with four being Klebsiella pneumoniae and two Enterobacter cloacae. All isolates except one K. pneumoniae were resistant to tigecycline, but only one K. pneumoniae was resistant to colistin. All produced a carbapenemase according to the Carba NP test, and all were positive for the EDTA-disk synergy test for detection of MBL. Using PCR followed by sequencing, the four K. pneumoniae isolates produced the carbapenemase NDM-1, while the two E. cloacae isolates produced the carbapenemase VIM-1. Genotyping analysis by Multilocus Sequence Typing (MLST) showed that three out of the four K. pneumoniae isolates were clonally related. They had been recovered from the same hospital and belonged to Sequence Type (ST) ST152. In contrast, the fourth K. pneumoniae isolate belonged to ST572. Noticeably, the NDM-1-producing K. pneumoniae additionally produced an extended-spectrum ß-lactamase (ESBL) of the CTX-M type, together with OXA-1 and TEM-1. Surprisingly, the three clonally related isolates produced different CTX-M variants, namely, CTX-M-3, CTX-M-57, and CTX-M-82, and coproduced QnrB, which confers quinolone resistance, and the 16S rRNA methylase RmtC, which confers high resistance to all aminoglycosides. The AAC(6')-Ib acetyltransferase was detected in both K. pneumoniae and E. cloacae. Mating-out assays using Escherichia coli as recipient were successful for all isolates. The bla NDM-1 gene was always identified on a 70-kb plasmid, whereas the bla VIM-1 gene was located on either a 60-kb or a 150-kb plasmid the two E. cloacae isolates, respectively. To the best of our knowledge, this is the first report of the coexistence of an MBL (NDM-1), an ESBL (CTX-M), a 16S rRNA methylase (RmtC), an acetyltransferase (AAC[6']-Ib), and a quinolone resistance enzyme (QnrB) in K. pneumoniae isolates recovered from different patients during an outbreak in a Saudi Arabian hospital.


Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Klebsiella/tratamento farmacológico , beta-Lactamases/genética , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/genética , Enterobacter cloacae/patogenicidade , Infecções por Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/microbiologia , Feminino , Humanos , Infecções por Klebsiella/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidade , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Arábia Saudita/epidemiologia
12.
Biomed Res Int ; 2018: 4208762, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30662908

RESUMO

Here, 210 healthy participants including community personnel (70), clinical students (68), and healthcare workers (HCWs) (72) from the eastern region of Saudi Arabia were studied. Sixty-three Staphylococcus aureus isolates were obtained from the nares of 37% of the community personnel and 26% of the clinical students and HCWs. Methicillin-resistant S. aureus (MRSA) was found in 16% (10 isolates) of the 63 isolates; six were from HCWs. Molecular characterization revealed high clonal diversity among the isolates, with 19 different spa types, 12 clonal complexes (CCs), and seven sequence types (STs) detected. The most common strain type was USA900, CC15, and t084, seen in 11 methicillin-susceptible S. aureus (MSSA) isolates. Moreover, three novel spa types in six isolates and one novel ST in two isolates were identified, most from HCWs. Interestingly, 29 isolates were mecA positive by PCR, whereas only 10 isolates were MRSA by disk diffusion (cefoxitin resistant). Of the 19 MSSA mecA-positive isolates, 16 were PBP2a negative, leaving three unique isolates from HCWs that were mecA and PBP2a positive yet cefoxitin susceptible. Our findings highlight the importance of phenotypically and genotypically characterizing S. aureus strains isolated from healthy communities to monitor the risk of possible cross-transmission to hospitalized patients. The identified strains showed a clonal lineage relationship with previously reported S. aureus and MRSA strains acquired from hospital settings.


Assuntos
Infecção Hospitalar/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Cavidade Nasal/microbiologia , Infecções Estafilocócicas/microbiologia , Adulto , Antibacterianos/uso terapêutico , Cefoxitina/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Feminino , Pessoal de Saúde , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Arábia Saudita , Infecções Estafilocócicas/tratamento farmacológico , Estudantes , Adulto Jovem
13.
Microb Drug Resist ; 23(5): 556-562, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27854148

RESUMO

This study was conducted to investigate the molecular epidemiology of resistance in Acinetobacter baumannii isolates collected at a hospital in Riyadh, Saudi Arabia, from January through December 2010. Twenty-seven A. baumannii were highly resistant (MIC90 > 256 µg/ml) to ceftazidime, cefepime, and aztreonam. Imipenem resistance was seen in 24 isolates, of which 18 had an minimum inhibitory concentration (MIC) >32 µg/mL. Ciprofloxacin, gentamicin, and amikacin resistance was found in 93%, 52%, and 37% of all the isolates, respectively. Moreover, 8 (30%) isolates showed colistin resistance, and 15 (56%) were found to have MICs ≥4 µg/mL for tigecycline. The frequency of ADC, GES-1, GES-11, and GES-5 were 96.3% (n = 26), 18.5% (n = 5), 11% (n = 3), and 3.7% (n = 1), respectively. OXA-23 was found in 63% (n = 17) of the isolates; ISAba1 was found upstream of OXA-23 in 16. OXA-24/40 was detected in only one strain. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis revealed that the 27 strains were distributed in 8 sequence types (STs) and 16 clonal pulsotypes (A-P). Five singleton STs were identified, including ST15 and ST113-ST116. The emergence of multidrug-resistant A. baumannii is becoming a major concern in Saudi Arabia. Metallo-ß-lactamases have no role in carbapenem resistance in this collection. The spread of OXA-23 in our strains occurred across different STs and pulsotypes, unlike what has been observed in many other countries. PFGE typing was more discriminatory than MLST. The high frequency of colistin and tigecycline resistance found in the isolates calls for continuous monitoring. This study describes the first identification of GES-5 conferring carbapenem resistance in A. baumannii.


Assuntos
Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Hospitais , beta-Lactamases/genética , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Carbapenêmicos/farmacologia , Cefalosporinas/farmacologia , Ciprofloxacina/farmacologia , Células Clonais , Colistina/farmacologia , Eletroforese em Gel de Campo Pulsado , Expressão Gênica , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Testes de Sensibilidade Microbiana , Minociclina/análogos & derivados , Minociclina/farmacologia , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Arábia Saudita/epidemiologia , Sorogrupo , Tigeciclina , beta-Lactamases/metabolismo
14.
Microb Drug Resist ; 23(1): 115-121, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27183378

RESUMO

Acinetobacter baumannii is currently considered as one of the most common successful pathogens in the healthcare system due to its ability to quickly develop resistance. Ten carbapenem-resistant A. calcoaceticus-baumannii complex were isolated from the eastern region, Saudi Arabia in 2014. All isolates were resistant to ciprofloxacin, however, 8 of 10 isolates were tigecycline resistant. Susceptibility test was also carried out for three aminoglycosides, resistance to gentamicin was 80%, amikacin was 90%, and tobramycin was 50%. Colistin susceptibility was seen in all isolates. The 10 isolates harbored blaOXA-23-like and ISAba1 and 9 of them also carried blaADC. Three isolates of 10 harbored blaNDM-1 coding for NDM metallo-ß-lactamase (MBL) with coexistence of blaADC together with either blaGES or blaTEM or both. Those three isolates exhibited negative Etest MBL screening test. Pulsed-field gel electrophoresis revealed the high clonal variability of the isolates, although two isolates were indistinguishable. The risk of dissemination of carbapenem resistance through presence of ISAba1 upstream of OXA-23-like in all isolates raises the concern about emergence of higher carbapenem prevalence rates in the future in our region. This study also demonstrated the importance of molecular surveillance to provide accurate and reliable data about the resistance rates of A. baumannii. Finally, the high incidence of NDM-1 among our isolates requires a routine surveillance to monitor the future prevalence of this enzyme in the region.


Assuntos
Infecções por Acinetobacter/epidemiologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética , Regulação Bacteriana da Expressão Gênica , Plasmídeos/metabolismo , beta-Lactamases/genética , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Carbapenêmicos/farmacologia , Ciprofloxacina/farmacologia , Eletroforese em Gel de Campo Pulsado , Transferência Genética Horizontal , Humanos , Testes de Sensibilidade Microbiana , Minociclina/análogos & derivados , Minociclina/farmacologia , Filogenia , Plasmídeos/química , Plasmídeos/classificação , Reação em Cadeia da Polimerase , Prevalência , Vigilância em Saúde Pública , Arábia Saudita/epidemiologia , Tigeciclina , beta-Lactamases/metabolismo
15.
Can J Infect Dis Med Microbiol ; 2016: 4379686, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27597874

RESUMO

Background. This study described various molecular and epidemiological characters determining antibiotic resistance patterns in Pseudomonas aeruginosa isolates. Methods. A total of 34 carbapenem-resistant P. aeruginosa clinical isolates were isolated from samples collected at a tertiary hospital in Riyadh, Saudi Arabia, from January to December 2011. Susceptibility testing, serotyping, molecular characterization of carbapenem resistance, and pulsed-field gel electrophoresis (PFGE) were performed. Results. All isolates were resistant to ceftazidime, and more than half were highly resistant (minimum inhibitory concentration (MIC) > 256 mg/L). Fifteen isolates had MIC values ≥64 mg/L for any of the carbapenems examined. Vietnamese extended-spectrum ß-lactamase (VEB-1) (n = 16/34) and oxacillinase (OXA-10) (n = 14/34) were the most prevalent extended-spectrum ß-lactamase and penicillinase, respectively. Verona imipenemase (VIM-1, VIM-2, VIM-4, VIM-11, and VIM-28) and imipenemase (IMP-7) variants were found in metallo-ß-lactamase producers. A decrease in outer membrane porin gene (oprD) expression was seen in nine isolates, and an increase in efflux pump gene (MexAB) expression was detected in five isolates. Six serotypes (O:1, O:4, O:7, O:10, O:11, and O:15) were found among the 34 isolates. The predominant serotype was O:11 (16 isolates), followed by O:15 (nine isolates). PFGE analysis of the 34 carbapenem-resistant P. aeruginosa isolates revealed 14 different pulsotypes. Conclusions. These results revealed diverse mechanisms conferring carbapenem resistance to P. aeruginosa isolates from Saudi Arabia.

16.
Biomed Res Int ; 2016: 3704150, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27340657

RESUMO

Background. Extended-spectrum ß-lactamases (ESßLs) and AmpC ß-lactamases cause ß-lactam resistance in Escherichia coli. Fecal colonization by ESßL- and/or AmpC-positive E. coli is a source of nosocomial infections. Methods. In order to investigate inpatient fecal colonization by ESßLs and AmpC, antibiotic sensitivity tests were conducted and minimum inhibitory concentrations (MICs) were determined using the disk diffusion method and E-test, respectively. Characterization of ESßL and AmpC was performed using E-test strips, and a set of PCRs and DNA sequence analyses were used to characterize the ESßL and AmpC genes. Results. The whole collection of E. coli isolates (n = 50) was sensitive to imipenem, tigecycline, colistin, and fosfomycin, while 26% of the isolates showed reduced susceptibility to ceftazidime (MIC ≥ 4 µg/mL). ESßL was phenotypically identified in 26% (13/50) of cases, while AmpC activity was detected in two ESßL-producing E. coli isolates. All ESßL-producing E. coli were positive for the CTX-M gene, eleven isolates carried bla CTX-M-15, and two isolates carried bla CTX-M-14 gene. Two CTX-M-positive E. coli isolates carried bla CMY-2. Conclusions. The alimentary tract is a significant reservoir for ESßL- and/or AmpC-producing E. coli, which may lead to nosocomial infection.


Assuntos
Proteínas de Bactérias/metabolismo , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Fezes/microbiologia , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Humanos , Testes de Sensibilidade Microbiana
17.
Jpn J Infect Dis ; 67(5): 382-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25241690

RESUMO

Two multidrug-resistant Pseudomonas aeruginosa strains harboring blaVIM were isolated from a hospital in Egypt and were indistinguishable by pulsed-field gel electrophoresis. Sequence analysis revealed a novel VIM ß-lactamase, VIM-28. Additional sequencing of integron revealed that the blaVIM-28 gene cassette had an unusual arrangement of class 1 integron structure, located directly downstream of the integrase gene "intI1" and oriented divergently from it. The new organization of integron also comprised the aacA7 and smr-2 gene cassettes in that order. A complete ISPa21 containing a tnpA gene flanked by two 13-bp inverted repeats was located directly upstream of the 3'-CS conserved region of the integron containing qacEΔ1/sul1 genes. The blaVIM-28-containing class 1 integron was found to have a chromosomal origin in both strains. In conclusion, the presence of a new variant of blaVIM, blaVIM-28, on a new organization of class 1 integron having ISPa21 increases the possibility of dissemination of resistance genes within the integron in P. aeruginosa among hospitalized patients in Egypt.


Assuntos
Integrons , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/genética , beta-Lactamases/genética , Farmacorresistência Bacteriana Múltipla , Egito , Eletroforese em Gel de Campo Pulsado , Ordem dos Genes , Humanos , Dados de Sequência Molecular , Tipagem Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Análise de Sequência de DNA
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