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1.
Braz. j. biol ; 83: e247016, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1339416

RESUMO

Abstract Pheretima posthuma (Vaillant, 1868), a native earthworm of Pakistan and Southeast Asia, has wide utilization in vermicomposting and bioremediation process. In this study, P. posthuma coelomic fluid (PCF) and body paste (PBP) was evaluated as antibacterial agent against ampicillin (AMP) resistant five Gram positive and four Gram negative clinical isolates. The antibacterial effect of different doses (i.e. 25-100 µg/ml) of PCF and PBP along with AMP and azithromycin (AZM) (negative and positive controls, respectively) were observed through disc diffusion and micro-dilution methods. All nine clinical isolates were noticed as AMP resistant and AZM sensitive. Antibacterial effects of PCF and PBP were dose dependent and zone of inhibitions (ZI) against all clinical isolates were between 23.4 ± 0.92 to 0 ± 00 mm. The sensitivity profile of PCF and PBP against clinical isolates was noticed as 44.44 and 55.56%, respectively. Both PCF and PBP showed bacteriostatic (BTS) action against S. aureus, S. pyogenes, K. pneumonia, N. gonorrhoeae. Moreover, the cumulative BTS potential of PCF and PBP against all isolates was 66.67 and 55.56%, respectively. The MICs of PCF and PBP were ranged from 50-200 µg/ml against selected isolates. The bacterial growth curves indicated that PCF and PBP inhibited the growth of all isolates at their specific MIC concentrations. However, PBP has better antibacterial potential compared to PCF against selected isolates. Therefore, it is concluded that both PCF and PBP of P. posthuma possess antibacterial and BTS potential against ampicillin resistant clinical isolates. This organism might be considered as a second choice of antibacterial agents and can further be utilized in pharmaceutical industries for novel drug manufacturing by prospecting bioactive potential agents.


Resumo Pheretima posthuma (Vaillant, 1868), uma minhoca nativa do Paquistão e sudeste da Ásia, tem ampla utilização em processos de vermicompostagem e biorremediação. Neste estudo, o fluido celômico de P. posthuma (PCF) e a pasta corporal (PBP) foram avaliados como agente antibacteriano contra cinco isolados clínicos Gram-positivos e quatro Gram-negativos resistentes à ampicilina (AMP). O efeito antibacteriano de diferentes doses (ou seja, 25-100 µg / ml) de PCF e PBP juntamente com AMP e azitromicina (AZM) (controles negativo e positivo, respectivamente) foi observado por meio de métodos de difusão em disco e microdiluição. Todos os nove isolados clínicos foram notados como resistentes a AMP e sensíveis a AZM. Os efeitos antibacterianos de PCF e PBP foram dependentes da dose e a zona de inibição (ZI) contra todos os isolados clínicos foi entre 23,4 ± 0,92 a 0 ± 00 mm. O perfil de sensibilidade do PCF e PBP contra isolados clínicos foi observado como 44,44% e 55,56%, respectivamente. Tanto o PCF quanto o PBP mostraram ação bacteriostática (BTS) contra S. aureus, S. pyogenes, K. pneumonia, N. gonorrhoeae. Além disso, o potencial BTS cumulativo de PCF e PBP contra todos os isolados foi de 66,67% e 55,56%, respectivamente. Os MICs de PCF e PBP variaram de 50-200 µg / ml contra isolados selecionados. As curvas de crescimento bacteriano indicaram que o PCF e o PBP inibiram o crescimento de todos os isolados em suas concentrações específicas de MIC. No entanto, PBP tem melhor potencial antibacteriano em comparação com PCF contra isolados selecionados. Portanto, conclui-se que tanto o PCF quanto o PBP de P. posthuma possuem potencial antibacteriano e BTS contra isolados clínicos resistentes à ampicilina. Esse organismo pode ser considerado como uma segunda escolha de agentes antibacterianos e pode ainda ser utilizado nas indústrias farmacêuticas para a fabricação de novos medicamentos por meio da prospecção de agentes com potencial bioativo.


Assuntos
Animais , Oligoquetos , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Ampicilina/farmacologia , Antibacterianos/farmacologia
2.
Zhongguo Zhong Yao Za Zhi ; 47(12): 3380-3385, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-35851132

RESUMO

The lack of rationality evaluation method for drug combination has long restricted its clinical application. In view of this, this study took Shuanghuanglian Injection as model drug and established a "physical-chemical-biological" sequential analysis method, which is expected to provide clues for improving the safety and effectiveness of clinical drug combination. With the methods of insoluble particle testing, isothermal titration calorimetry(ITC), and real time cellular analysis(RTCA), the rationality of Shuanghuanglian Injection combined with Ampicillin Sodium for Injection was assessed. The results showed that the number of insoluble particles>10 µm in the solution of the combination met the standard of Chinese Pharmacopoeia, while the number of insoluble particles>25 µm did not meet the standard. ITC detection demonstrated that the change of Gibbs free energy(ΔG) was less than 0 during the fusion process, indicating that the process was spontaneous and enthalpy-driven reaction. Therefore, the interaction between the two was mainly chemical reaction, and the internal substances may change. RTCA found that Shuanghuanglian Injection alone and Ampicillin Sodium for Injection alone basically had no inhibitory effect on the growth of HEK293 T cells, while the combination of the two suppressed the growth of HEK293 T cells, suggesting that the combination was toxic to HEK293 T cells. This study showed that Shuanghuanglian Injection and Ampicillin Sodium for Injection reacted, yielding toxicity. This suggested that the two should not be combined for application. With the "physical-chemical-biological" sequential analysis, the molecular interaction of drugs was clarified. The method can be further applied for evaluating the rationality of other Chinese and western medicine injections.


Assuntos
Ampicilina , Medicamentos de Ervas Chinesas , Ampicilina/farmacologia , Calorimetria , Combinação de Medicamentos , Medicamentos de Ervas Chinesas/química , Células HEK293 , Humanos , Injeções
3.
Front Cell Infect Microbiol ; 12: 869339, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35646717

RESUMO

Listeria monocytogenes is an opportunistic intracellular pathogen causing an infection termed listeriosis. Despite the low incidence of listeriosis, the high mortality rate in individuals at risk makes this bacterium one of the most dangerous foodborne pathogens. Reports about a relapse of infection after antibiotic treatment suggest that the bacteria may be able to evade antibiotic treatment and persist as a dormant, antibiotic-tolerant subpopulation. In this study, we observed intracellular generation of antibiotic-resistant L-forms of Listeria monocytogenes following Ampicillin treatment of Listeria monocytogenes infected cells. Detection and identification of intracellular Listeria L-forms was performed by a combination of fluorescence in-situ hybridization and confocal laser scanning microscopy. Using micromanipulation, it was possible to isolate single intracellular L-form cells that following transfer into fresh medium gave rise to pure cultures. In conclusion, the results obtained here provide strong evidence that antibiotic treatment of infected host cells can induce the formation of L-forms from intracellular Listeria monocytogenes. Furthermore, our results suggest that intracellular L-forms persist inside host cells and that they represent viable bacteria, which are still able to grow and proliferate.


Assuntos
Listeria monocytogenes , Listeriose , Ampicilina/farmacologia , Antibacterianos/farmacologia , Humanos , Listeriose/tratamento farmacológico , Listeriose/microbiologia
4.
J Pak Med Assoc ; 72(6): 1053-1056, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35751308

RESUMO

OBJECTIVE: To assess resistance-loss due to plasmid elimination under experimental conditions, including withdrawal of antibiotics and administration of starvation conditions. METHODS: The experimental study was conducted at the Department of Pathology, King Edward Medical University, Lahore, Pakistan, from July to December 2019. A single sensitive clinical isolate of escherichia coli, showing resistance towards ampicillin was collected and separately sub-cultured in three different culture broths: tryptic soya broth, minimal broth and control broth for a period of one month under standard laboratory conditions. Minimum inhibitory concentrations of the strains were calculated after every seven days to check antibiotic susceptibility. RESULTS: Minimum inhibitory concentrations of the initial escherichia coli strain measured on Day 1 was 6mg/mL and it became sensitive after continual sub-culturing in the absence of antibiotics in 21 days. Due to starvation conditions, the bacterial strain exhibited sensitivity to an even lower antibiotic concentration of 1.5mg/mL on the 28th day. Bacterial growth inhibition zones determined by disc diffusion method using an ampicillin disc of 10µg/mL showed no zone of inhibition. CONCLUSIONS: Provision of starvation conditions and withdrawal of antibiotic allowed the escherichia coli strain to exhibit gradual loss of resistance over a period of time.


Assuntos
Antibacterianos , Escherichia coli , Ampicilina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética
5.
Appl Environ Microbiol ; 88(12): e0033322, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35638841

RESUMO

The remarkable ability of Agrobacterium tumefaciens to transfer DNA to plant cells has allowed the generation of important transgenic crops. One challenge of A. tumefaciens-mediated transformation is eliminating the bacteria after plant transformation to prevent detrimental effects to plants and the release of engineered bacteria to the environment. Here, we use a reverse-genetics approach to identify genes involved in ampicillin resistance, with the goal of utilizing these antibiotic-sensitive strains for plant transformations. We show that treating A. tumefaciens C58 with ampicillin led to increased ß-lactamase production, a response dependent on the broad-spectrum ß-lactamase AmpC and its transcription factor, AmpR. Loss of the putative ampD orthologue atu2113 led to constitutive production of AmpC-dependent ß-lactamase activity and ampicillin resistance. Finally, one cell wall remodeling enzyme, MltB3, was necessary for the AmpC-dependent ß-lactamase activity, and its loss elicited ampicillin and carbenicillin sensitivity in the A. tumefaciens C58 and GV3101 strains. Furthermore, GV3101 ΔmltB3 transforms plants with efficiency comparable to that of the wild type but can be cleared with sublethal concentrations of ampicillin. The functional characterization of the genes involved in the inducible ampicillin resistance pathway of A. tumefaciens constitutes a major step forward in efforts to reduce the intrinsic antibiotic resistance of this bacterium. IMPORTANCE Agrobacterium tumefaciens, a significant biotechnological tool for production of transgenic plant lines, is highly resistant to a wide variety of antibiotics, posing challenges for various applications. One challenge is the efficient elimination of A. tumefaciens from transformed plant tissue without using levels of antibiotics that are toxic to the plants. Here, we present the functional characterization of genes involved in ß-lactam resistance in A. tumefaciens. Knowledge about proteins that promote or inhibit ß-lactam resistance will enable the development of strains to improve the efficiency of Agrobacterium-mediated plant genetic transformations. Effective removal of Agrobacterium from transformed plant tissue has the potential to maximize crop yield and food production, improving the outlook for global food security.


Assuntos
Agrobacterium tumefaciens , Resistência beta-Lactâmica , Agrobacterium tumefaciens/fisiologia , Ampicilina/farmacologia , Antibacterianos/farmacologia , Glicosiltransferases , Plantas Geneticamente Modificadas/genética , Resistência beta-Lactâmica/genética , beta-Lactamases/genética
6.
Microbiol Spectr ; 10(3): e0257921, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35536039

RESUMO

Antibiotics are important for the treatment and prevention of invasive Haemophilus influenzae disease. Reduced susceptibility to clinically relevant drugs, except ampicillin, has been uncommon in the United States. Susceptibility of 700 invasive H. influenzae isolates, collected through population-based surveillance during 2016, was assessed for 15 antibiotics using broth microdilution, according to the CLSI guidelines; a subset of 104 isolates were also assessed for rifampin susceptibility using Etest. Genomes were sequenced to identify genes and mutations known to be associated with reduced susceptibility to clinically relevant drugs. A total of 508 (72.6%) had reduced susceptibility to at least one antibiotic and more than half of the isolates exhibited reduced susceptibility to only one (33.6%) or two (21.6%) antibiotic classes. All tested isolates were susceptible to rifampin, a chemoprophylaxis agent, and <1% (n = 3) of isolates had reduced susceptibility to third generation cephalosporins, which are recommended for invasive disease treatment. In contrast, ampicillin resistance was more common (28.1%) and predominantly associated with the detection of a ß-lactamase gene; 26.2% of isolates in the collection contained either a TEM-1 or ROB-1 ß-lactamase gene, including 88.8% of ampicillin-resistant isolates. ß-lactamase negative ampicillin-resistant (BLNAR) isolates were less common and associated with ftsI mutations; resistance to amoxicillin-clavulanate was detected in <2% (n = 13) of isolates. The proportion of reduced susceptibility observed was higher among nontypeable H. influenzae and serotype e than other serotypes. US invasive H. influenzae isolates remain predominantly susceptible to clinically relevant antibiotics except ampicillin, and BLNAR isolates remain uncommon. IMPORTANCE Antibiotics play an important role for the treatment and prevention of invasive Haemophilus influenzae disease. Antimicrobial resistance survey of invasive H. influenzae isolates collected in 2016 showed that the US H. influenzae population remained susceptible to clinically relevant antibiotics, except for ampicillin. Detection of approximately a quarter ampicillin-resistant and ß-lactamase containing strains demonstrates that resistance mechanisms can be acquired and sustained within the H. influenzae population, highlighting the continued importance of antimicrobial resistance surveillance for H. influenzae to monitor susceptibility trends and mechanisms of resistance.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Haemophilus influenzae , Ampicilina/farmacologia , Ampicilina/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Haemophilus/tratamento farmacológico , Infecções por Haemophilus/epidemiologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/genética , Humanos , Testes de Sensibilidade Microbiana , Rifampina/farmacologia , Rifampina/uso terapêutico , Estados Unidos/epidemiologia , beta-Lactamases/genética
7.
Molecules ; 27(9)2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35566294

RESUMO

This study was focused on synthesizing, characterizing, and evaluating the antimicrobial effect of polymer nanoparticles (NPs) loaded with ampicillin. For this, the NPs were produced through polymeric self-assembly in aqueous media assisted by high-intensity sonication, using anionic polymers corresponding to the sodium salts of poly(maleic acid-co-vinylpyrrolidone) and poly(maleic acid-co-vinylpyrrolidone) modified with decyl-amine, here named as PMA-VP and PMA-VP-N10, respectively. The polymeric NPs were analyzed and characterized through the formation of polymeric pseudo-phases utilizing pyrene as fluorescent probe, as well as by measurements of particle size, zeta potential, polydispersity index, and encapsulation efficiency. The antimicrobial effect was evaluated by means of the broth microdilution method employing ampicillin sensitive and resistant Staphylococcus aureus strains. The results showed that PMA-VP and PMA-VP-N10 polymers can self-assemble, forming several types of hydrophobic pseudo-phases with respect to the medium pH and polymer concentration. Likewise, the results described that zeta potential, particle size, polydispersity index, and encapsulation efficiency are extremely dependent on the medium pH, whereas the antimicrobial activity displayed an interesting recovery of antibiotic activity when ampicillin is loaded in the polymeric NPs.


Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Ampicilina/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Maleatos , Nanopartículas/química , Tamanho da Partícula , Polímeros/química , Staphylococcus aureus
8.
Emerg Infect Dis ; 28(6): 1110-1116, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35608550

RESUMO

Annually, Shigella spp. cause ≈188 million cases of diarrheal disease globally, including 500,000 cases in the United States; rates of antimicrobial resistance are increasing. To determine antimicrobial resistance and risk factors in San Diego, California, USA, we retrospectively reviewed cases of diarrheal disease caused by Shigella flexneri and S. sonnei diagnosed during 2017-2020. Of 128 evaluable cases, S. flexneri was slightly more common than S. sonnei; most cases were in persons who were gay or bisexual cisgender men, were living with HIV, were unhoused, or used methamphetamines. Overall, rates of resistance to azithromycin, fluoroquinolones, ampicillin, and trimethoprim/sulfamethoxazole (TMP/SMX) were comparable to the most recent national data reported from the Centers for Disease Control and Prevention; 55% of isolates were resistant to azithromycin, 23% to fluoroquinolones, 70% to ampicillin, and 83% to TMP/SMX. The rates that we found for TMP/SMX were slightly higher than those in national data.


Assuntos
Anti-Infecciosos , Disenteria Bacilar , Shigella , Ampicilina/farmacologia , Ampicilina/uso terapêutico , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Azitromicina/farmacologia , Azitromicina/uso terapêutico , California/epidemiologia , Diarreia , Farmacorresistência Bacteriana , Disenteria Bacilar/epidemiologia , Fluoroquinolonas/farmacologia , Fluoroquinolonas/uso terapêutico , Humanos , Masculino , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Shigella sonnei , Combinação Trimetoprima e Sulfametoxazol/farmacologia , Estados Unidos
9.
BMC Microbiol ; 22(1): 127, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35549853

RESUMO

BACKGROUND: The discovery of new molecules with antimicrobial properties has been a promising approach, mainly when related to substances produced by bacteria. The use of substances produced by bees has evidenced the antimicrobial action in different types of organisms. Thus, the use of bacteria isolated from larval food of stingless bees opens the way for the identification of the new molecules. The effect of supernatants produced by these bacteria was evaluated for their ability to inhibit the growth of bacteria of clinical interest. Furthermore, their effects were evaluated when used in synergy with antibiotics available in the pharmaceutical industry. RESULTS: A few supernatants showed an inhibitory effect against susceptible and multiresistant strains in the PIC assay and the modulation assay. Emphasizing the inhibitory effect on multidrug-resistant strains, 7 showed an effect on multidrug-resistant Escherichia coli (APEC), Klebsiella pneumoniae carbapenemase (KPC), multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Staphylococcus aureus (MRSA) in the PIC assay. Of the supernatants analyzed, some presented synergism for more than one species of multidrug-resistant bacteria. Nine had a synergistic effect with ampicillin on E. coli (APEC) or S. aureus (MRSA), 5 with penicillin G on E. coli (APEC) or KPC, and 3 with vancomycin on KPC. CONCLUSION: In summary, the results indicate that supernatants produced from microorganisms can synthesize different classes of molecules with potent antibiotic activity against multiresistant bacteria. Thus, suggesting the use of these microorganisms for use clinical tests to isolate the molecules produced and their potential for use.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Staphylococcus aureus , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Bactérias , Abelhas , Brasil , Escherichia coli , Klebsiella pneumoniae , Larva , Testes de Sensibilidade Microbiana
10.
Int J Mol Sci ; 23(9)2022 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-35563620

RESUMO

Cefotaximase-Munich (CTX-M) extended-spectrum beta-lactamases (ESBLs) are commonly associated with Gram-negative, hospital-acquired infections worldwide. Several beta-lactamase inhibitors, such as clavulanate, are used to inhibit the activity of these enzymes. To understand the mechanism of CTX-M-15 activity, we have determined the crystal structures of CTX-M-15 in complex with two specific classes of beta-lactam compounds, desfuroylceftiofur (DFC) and ampicillin, and an inhibitor, clavulanic acid. The crystal structures revealed that Ser70 and five other residues (Lys73, Tyr105, Glu166, Ser130, and Ser237) participate in catalysis and binding of those compounds. Based on analysis of steady-state kinetics, thermodynamic data, and molecular docking to both wild-type and S70A mutant structures, we determined that CTX-M-15 has a similar affinity for all beta-lactam compounds (ceftiofur, nitrocefin, DFC, and ampicillin), but with lower affinity for clavulanic acid. A catalytic mechanism for tested ß-lactams and two-step inhibition mechanism of clavulanic acid were proposed. CTX-M-15 showed a higher activity toward DFC and nitrocefin, but significantly lower activity toward ampicillin and ceftiofur. The interaction between CTX-M-15 and both ampicillin and ceftiofur displayed a higher entropic but lower enthalpic effect, compared with DFC and nitrocefin. DFC, a metabolite of ceftiofur, displayed lower entropy and higher enthalpy than ceftiofur. This finding suggests that compounds containing amine moiety (e.g., ampicillin) and the furfural moiety (e.g., ceftiofur) could hinder the hydrolytic activity of CTX-M-15.


Assuntos
Antibacterianos , beta-Lactamases , Ampicilina/farmacologia , Antibacterianos/química , Cefalosporinas , Ácido Clavulânico/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , beta-Lactamases/metabolismo
11.
J Equine Vet Sci ; 115: 104020, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35605881

RESUMO

The pharmacokinetics of ampicillin-cloxacillin, given as single intravenously dose of 10 mg.kg-1 (5 mg.kg-1 of ampicillin plus 5 mg.kg-1 of cloxacillin) was examined in clinically presented Indian thoroughbred horses (n = 6) in order to design appropriate dosing strategies. Drug concentrations in plasma were determined by high performance liquid chromatography (HPLC) and pharmacokinetic parameters were derived by non-compartmental analysis using WinNonlin software. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ampicillin-cloxacillin against quality control strains of Escherichia coli and Staphylococcus aureus, grown in Muller Hinton Broth, were determined by broth microdilution method. For ampicillin, area under plasma drug concentration time curve (AUC) was 15.2 ± 0.54 µg.h.ml-1, mean residence time (MRT) was 1.33 ± 0.06 h and clearance (Cl) was 0.33 ± 0.01 L.h-1.kg-1. For cloxacillin, AUC was 18.0 ± 0.9 µg.h.ml-1, MRT was 1.28 ± 0.02 h and Cl was 0.28 ± 0.01 L.h-1.kg-1. MIC of ampicillin-cloxacillin combination against E. coli and S. aureus was determined to be 0.4 µg.ml-1. PK-PD integration indicated that to maintain %T > MIC value 50% for bacteria with MIC ≤ 0.4 µg.ml-1, an appropriate intravenous dosage regimen of ampicillin-cloxacillin combination in horses would be 15 mg.kg-1 (i.e. 7.5 mg.kg-1 of ampicillin plus 7.5 mg.kg-1 of cloxacillin), to be repeated at 12 h intervals. Safety profile of the recommended regimen did not significantly alter any of the 16 biochemical or haematological parameters studied.


Assuntos
Escherichia coli , Staphylococcus aureus , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Cloxacilina/farmacologia , Cavalos
12.
Microb Pathog ; 168: 105573, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35588966

RESUMO

Vibrio parahaemolyticus is strongly resistant to ampicillin (AMP). In this study, AMP-resistant genes in V. parahaemolyticus ATCC33846 were characterized. Transcriptomic analysis of V. parahaemolyticus exposed to AMP revealed 4608 differentially transcribed genes, including 670 significantly up-regulated genes and 655 significantly down-regulated genes. Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, significantly modulated genes in ATCC33846 under AMP stimulation were observed in the following categories: microbial metabolism in diverse environments, metabolic pathways, bacterial secretion system, citrate cycle, biofilm formation, oxidative phosphorylation, ribosome, citrate cycle, pyruvate metabolism, carbon metabolism, nitrogen metabolism, fatty acid metabolism and tryptophan metabolism. The genes VPA0510, VPA0252, VPA0699, VPA0768, VPA0320, VP0636, VPA1096, VPA0947 and VP1775 were significantly up-regulated at the similar level to blaA in V. parahaemolyticus under AMP stimulation, and their overexpression in V. parahaemolyticus could increase its resistance to AMP. These results indicate that AMP has a global influence on V. parahaemolyticus cells. The findings would provide new insights into the resistant mechanism of V. parahaemolyticus to AMP, which would be helpful for developing novel drugs for treating V. parahaemolyticus infection.


Assuntos
Vibrio parahaemolyticus , Monofosfato de Adenosina , Ampicilina/farmacologia , Citratos , Perfilação da Expressão Gênica , Vibrio parahaemolyticus/genética
13.
Eur J Clin Microbiol Infect Dis ; 41(6): 961-969, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35585442

RESUMO

Haemophilus influenzae is a human-specific pathogen responsible for respiratory tract infections, meningitis, and sepsis. The study aimed to characterize antibiotic resistance in H. influenzae strains isolated from patients with lower respiratory tract infections over 15 years in Poland. The minimum inhibitory concentrations (MICs) of clinically relevant antibiotics were determined by broth microdilution method. Screening for beta-lactam resistance was performed in all isolates following EUCAST recommendation. Finally, relevant changes in penicillin-binding protein 3 (PBP3) were detected by PCR screening. Of the 1481 isolates collected between 2005 and 2019, 12.6%, 0.2%, 17.1%, and 0.2% were resistant to ampicillin, amoxicillin/clavulanate, cefuroxime, and ceftriaxone, respectively. Among them, 74.4% (1102/1481) of isolates were categorized as BLNAS (ß-lactamase negative, ampicillin-susceptible), 13.0% (192/1481) as BLNAS with modified PBP3 (mutations in ftsI gene), 2.6% (39/1481) as BLNAR (ß-lactamase negative, ampicillin-resistant), and 0.2% had PBP3 modifications typical for high-BLNAR. Production of ß-lactamase characterized 9.7% of isolates (8.6% BLPAR-ß-lactamase-positive, ampicillin-resistant, and 1.1% BLPACR-ß-lactamase-positive, amoxicillin-clavulanate resistant). Three isolates with PBP3 modifications typical for high-BLNAR proved resistant to ceftriaxone (MIC > 0.125 mg/L). Resistance to ciprofloxacin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole was observed in 0.1%, 0.5%, 1.6%, and 24.7% of isolates, respectively. This is the first report of Polish H. influenzae isolates resistant to third-generation cephalosporins. Polish H. influenzae isolates demonstrate similar susceptibility trends as in many other countries. The substantial proportion of ß-lactam-resistant isolates and the emergence of those resistant to third-generation cephalosporins are of great concern and should be under surveillance.


Assuntos
Infecções por Haemophilus , Infecções Respiratórias , Combinação Amoxicilina e Clavulanato de Potássio , Ampicilina/farmacologia , Antibacterianos/farmacologia , Ceftriaxona , Farmacorresistência Bacteriana , Infecções por Haemophilus/epidemiologia , Infecções por Haemophilus/microbiologia , Haemophilus influenzae/genética , Humanos , Testes de Sensibilidade Microbiana , Polônia/epidemiologia , Infecções Respiratórias/epidemiologia , beta-Lactamases/genética
14.
Infect Immun ; 90(6): e0011922, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35587200

RESUMO

Antibiotic resistance of pathogenic bacteria has emerged as a major threat to public health worldwide. While stable resistance due to the acquisition of genomic mutations or plasmids carrying antibiotic resistance genes is well established, much less is known about the temporary and reversible resistance induced by antibiotic treatment, such as that due to treatment with bacterial cell wall-inhibiting antibiotics such as ampicillin. Typically, ampicillin concentration in the blood and other tissues gradually increases over time after initiation of the treatment. As a result, the bacterial population is exposed to a concentration gradient of ampicillin during the treatment of infectious diseases. This is different from in vitro drug testing, where the organism is exposed to fixed drug concentrations from the beginning until the end. To mimic the mode of antibiotic exposure of microorganisms within host tissues, we cultured the wild-type, ampicillin-sensitive Salmonella enterica serovar Typhi Ty2 strain (S. Typhi Ty2) in the presence of increasing concentrations of ampicillin over a period of 14 days. This resulted in the development of a strain that displayed several features of the so-called L-form of bacteria, including the absence of the cell wall, altered shape, and lower growth rate compared with the parental form. Studies of the pathogenesis of S. Typhi L-form showed efficient infection of the murine and human macrophage cell lines. More importantly, S. Typhi L-form was also able to establish infection in a mouse model to the extent comparable to its parental form. These results suggested that L-form generation following the initiation of treatment with antibiotics could lead to drug escape of S. Typhi and cell to cell (macrophages) spread of the bacteria, which sustain the infection. Oral infection by the L-form bacteria underscores the potential of rapid disease transmission through the fecal-oral route, highlighting the need for new approaches to decrease the reservoir of infection.


Assuntos
Ampicilina , Salmonella typhi , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Linhagem Celular , Macrófagos/microbiologia , Camundongos , Salmonella typhi/genética
15.
Nat Biomed Eng ; 6(7): 910-921, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35411114

RESUMO

Antibiotic-induced alterations in the gut microbiota are implicated in many metabolic and inflammatory diseases, increase the risk of secondary infections and contribute to the emergence of antimicrobial resistance. Here we report the design and in vivo performance of an engineered strain of Lactococcus lactis that altruistically degrades the widely used broad-spectrum antibiotics ß-lactams (which disrupt commensal bacteria in the gut) through the secretion and extracellular assembly of a heterodimeric ß-lactamase. The engineered ß-lactamase-expression system does not confer ß-lactam resistance to the producer cell, and is encoded via a genetically unlinked two-gene biosynthesis strategy that is not susceptible to dissemination by horizontal gene transfer. In a mouse model of parenteral ampicillin treatment, oral supplementation with the engineered live biotherapeutic minimized gut dysbiosis without affecting the ampicillin concentration in serum, precluded the enrichment of antimicrobial resistance genes in the gut microbiome and prevented the loss of colonization resistance against Clostridioides difficile. Engineered live biotherapeutics that safely degrade antibiotics in the gut may represent a suitable strategy for the prevention of dysbiosis and its associated pathologies.


Assuntos
Clostridioides difficile , Disbiose , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Disbiose/induzido quimicamente , Disbiose/tratamento farmacológico , Disbiose/prevenção & controle , Camundongos , beta-Lactamases/metabolismo
16.
J Antibiot (Tokyo) ; 75(6): 354-359, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35459856

RESUMO

Epsilon-poly-L-lysine (EPL) is an antimicrobial peptide with low mammalian toxicity; thus, it is commonly used as food preservative. Here, the capacity of EPL to improve the efficacy of the antibiotics ampicillin (AMP), gentamycin (GEN), tetracycline (TCN), and methicillin (MET) against four bacterial pathogens, namely Pseudomonas aeruginosa PAO1, Klebsiella pneumoniae CG43, MET-sensitive Staphylococcus aureus ATCC 25923 (MSSA), and MET-resistant S. aureus ATCC 33591 (MRSA), was investigated. Some antibiotic-EPL combinations, i.e., AMP-EPL, GEN-EPL, and TCN-EPL, were particularly active against the pathogens through synergy, partial synergy, or additive effects. Additionally, MET-EPL displayed a partial synergistic effect against MRSA. GEN-EPL had the most powerful antimicrobial effect against MSSA: it eradicated the bacterium within an hour. Conversely, AMP-EPL and MET-EPL were the least potent combinations against MRSA, and TCN-EPL was least potent against K. pneumoniae; for these combinations, bactericidal activities occurred >10 h after initial treatments. All antibiotic-EPL treatments showed inhibitory activities against P. aeruginosa biofilm formation and enhanced preformed biofilm disruption in vitro. Similarly, the inhibition of biofilm formation on a porcine skin model was observed. Moreover, no significant cytotoxicity was detected for any antibiotic-EPL treatment in tests using Balb/3t3 fibroblasts. Given the rise in antibiotic-resistant bacteria, combining antibiotics with EPL may enhance antibiotic effectiveness, as shown in this study, while helping to avoid antimicrobial resistance.


Assuntos
Antibacterianos , Staphylococcus aureus Resistente à Meticilina , Monofosfato de Adenosina , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias , Gentamicinas/farmacologia , Mamíferos , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Polilisina/farmacologia , Pseudomonas aeruginosa , Suínos
17.
Vet Microbiol ; 269: 109428, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35427993

RESUMO

The association between changes in the respiratory microbiota and Bovine Respiratory Disease (BRD) in dairy calves is not well understood. We investigated characteristics of the nasopharyngeal (NP) microbiota associated with BRD following Pasteurella multocida infection. We also evaluated the effect of ampicillin on the respiratory microbiota. Calves (n = 30) were inoculated with P. multocida and randomly allocated into an antibiotic group (AMP; n = 17) or placebo group (PLAC; n = 11) when lung lesions developed. Deep NP swabs (DNPS) were collected before and after challenge. Monitoring was performed daily until euthanasia at day 14. Swabs and tissue samples were collected for analysis. The V4 hypervariable region of the 16 S rRNA gene was amplified and sequenced on an Illumina MiSeq. Increased species abundance in the pre-challenge DNPS was associated with a decrease in cumulative respiratory disease over 14 days post-infection. While NP beta diversity was affected by infection, antibiotic therapy showed no effect on the alpha and beta diversity nor the relative abundance (RA) of genera in the NP tonsil, lymph node and lung microbiota. Antibiotic therapy was associated with an increased RA of NP Pasteurella spp. and a decreased RA of NP Prevotella spp. Common taxa among all samples included GIT-associated bacteria, which suggests a possible link between the GIT microbiota and respiratory microbiota in dairy calves.


Assuntos
Doenças dos Bovinos , Microbiota , Pasteurella multocida , Doenças Respiratórias , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Bactérias/genética , Bovinos , Doenças dos Bovinos/microbiologia , Pulmão/microbiologia , Pasteurella multocida/genética , Doenças Respiratórias/veterinária
18.
Am J Health Syst Pharm ; 79(13): 1056-1065, 2022 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-35299243

RESUMO

PURPOSE: The purpose of this review is to describe the theory behind and data supporting use of aminopenicillins in the treatment of ampicillin-resistant enterococcal urinary tract infections. SUMMARY: Aminopenicillin concentrations in the urine may be high enough to achieve bacterial eradication and clinical cure for infections affecting the lower genitourinary tract, even in the context of in vitro resistance based on established susceptibility breakpoints. A literature search was conducted to identify original research articles describing the use of aminopenicillins in the treatment of urinary tract infections caused by ampicillin-resistant Enterococcus species. Three published retrospective cohort studies were identified, all of which reported that aminopenicillins had similar rates of clinical cure as other antibiotic classes prescribed for the treatment of enterococcal urinary tract infections. CONCLUSION: Both pharmacokinetic/pharmacodynamic principles and limited retrospective clinical data support the use of aminopenicillins in the treatment of lower urinary tract infections caused by Enterococcus species, even when the isolates have a minimum inhibitory concentration that exceeds the susceptibility breakpoint.


Assuntos
Infecções por Bactérias Gram-Positivas , Infecções Urinárias , Ampicilina/farmacologia , Ampicilina/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Enterococcus , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia
19.
Microbiol Spectr ; 10(2): e0190421, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35311555

RESUMO

Oral antibiotics remain the therapy of choice for severe bacterial infections; however, antibiotic use disrupts the intestinal microbiota, increasing the risk of colonization by intestinal pathogens. Currently, our understanding of antibiotic-mediated disturbances of the microbiota remains at the level of bacterial families or specific species, and little is known about the effect of antibiotics on potentially beneficial and pathogenic bacteria under the conditions of gut microbiota dysbiosis. Additionally, the question of whether the effects of antibiotics on the gut microbiota are temporary or permanent is controversial. In this study, we used 16S rRNA gene sequencing to evaluate the short- and long-term effects of ampicillin, vancomycin, metronidazole, and neomycin on the murine intestinal microbiota. We found that the changes in the intestinal microbiota reflected the antibiotics' mechanisms of action and that dysbiosis of the intestinal microbiota led to competition between different bacterial communities. In particular, an increase in Enterococcus, which accompanies a decrease in probiotics-related genera such as Lactobacillus, is commonly seen across antibiotic treatments. In addition, we found that these oral antibiotics had long-term negative effects on the intestinal microbiota and promoted the development of antibiotic-resistant bacterial strains. These results indicate that ampicillin, vancomycin, metronidazole, and neomycin have long-term negative effects and can cause irreversible changes in the diversity of the intestinal microbiota, thereby increasing the risk of host disease. IMPORTANCE The intestinal microbiota is a dynamic community of hundreds of millions of microorganisms that play important roles in human health. However, treatment with antibiotics can disrupt the delicate balance of this community, leading to deleterious effects on the host such as inflammation and enhanced susceptibility to infection. To date, most studies of the effects of antibiotic treatment on the microbiota have focused on specific intestinal pathogens and bacterial families. However, few studies have investigated the effects of antibiotic treatment on the relative abundance of probiotic bacteria, pathogenic bacteria, and opportunistic bacterial pathogens in the gut.


Assuntos
Microbioma Gastrointestinal , Ampicilina/farmacologia , Animais , Antibacterianos/uso terapêutico , Bactérias/genética , Disbiose/microbiologia , Humanos , Metronidazol/farmacologia , Camundongos , Neomicina/farmacologia , RNA Ribossômico 16S/genética , Vancomicina/farmacologia
20.
J Bacteriol ; 204(4): e0001022, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35352964

RESUMO

Bacterial resistance to ß-lactam antibiotics is often mediated by ß-lactamases and lytic transglycosylases. Azospirillum baldaniorum Sp245 is a plant-growth-promoting rhizobacterium that shows high levels of resistance to ampicillin. Investigating the molecular basis of ampicillin resistance and its regulation in A. baldaniorum Sp245, we found that a gene encoding lytic transglycosylase (Ltg1) is organized divergently from a gene encoding an extracytoplasmic function (ECF) σ factor (RpoE7) in its genome. Inactivation of rpoE7 in A. baldaniorum Sp245 led to increased ability to form cell-cell aggregates and produce exopolysaccharides and biofilm, suggesting that rpoE7 might contribute to antibiotic resistance. Inactivation of ltg1 in A. baldaniorum Sp245, however, adversely affected its growth, indicating a requirement of Ltg1 for optimal growth. The expression of rpoE7, as well that of as ltg1, was positively regulated by RpoE7, and overexpression of RpoE7 conferred ampicillin sensitivity to both the rpoE7::km mutant and its parent. In addition, RpoE7 negatively regulated the expression of a gene encoding a ß-lactamase (bla1). Out of the 5 paralogs of RpoH encoded in the genome of A. baldaniorum Sp245, RpoH3 played major roles in conferring ampicillin sensitivity and in the downregulation of bla1. The expression of rpoH3 was positively regulated by RpoE7. Collectively, these observations reveal a novel regulatory cascade of RpoE7-RpoH3 σ factors that negatively regulates ampicillin resistance in A. baldaniorum Sp245 by controlling the expression of a ß-lactamase and a lytic transglycosylase. In the absence of a cognate anti-sigma factor, addressing how the activity of RpoE7 is regulated by ß-lactams will unravel new mechanisms of regulation of ß-lactam resistance in bacteria. IMPORTANCE Antimicrobial resistance is a global health problem that requires a better understanding of the mechanisms that bacteria use to resist antibiotics. Bacteria inhabiting the plant rhizosphere are a potential source of antibiotic resistance, but their mechanisms controlling antibiotic resistance are poorly understood. A. baldaniorum Sp245 is a rhizobacterium that is known for its characteristic resistance to ampicillin. Here, we show that an AmpC-type ß-lactamase and a lytic transglycosylase mediate resistance to ampicillin in A. baldaniorum Sp245. While the gene encoding lytic transglycosylase is positively regulated by an ECF σ-factor (RpoE7), a cascade of RpoE7 and RpoH3 σ factors negatively regulates the expression of ß-lactamase. This is the first evidence showing involvement of a regulatory cascade of σ factors in the regulation of ampicillin resistance in a rhizobacterium.


Assuntos
Azospirillum , Fator sigma , Ampicilina/farmacologia , Antibacterianos/farmacologia , Azospirillum/metabolismo , Glicosiltransferases/genética , Fator sigma/genética , Fator sigma/metabolismo , Resistência beta-Lactâmica/genética , beta-Lactamases/genética
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