Are Probiotic Really Safe for Humans?

Probiotic bacteria have been used as a health-promoting factor for a very long time. Nowadays, products containing probiotic bacteria are becoming more and more popular on the market. The term probiotics refers to the products belonging to the following groups: probiotic drugs (medicinal products – live biotherapeutic products for human use), medical devices, probiotic foods (e.g. foods, food ingredients, dietary supplements or food for special medical purposes), directly fed microorganisms (for animal use) and designer probiotics (genetically modified probiotics). Safety assessment of bacterial strains used as probiotics should be carefully studied. Even though probiotic bacteria have the generally recognized as safe (GRAS status), there are several reports about side effects triggered by the presence of these organisms. Microorganisms used as probiotics may cause systemic infections, stimulate the immune system, disturb metabolism and participate in horizontal gene transfer

Estimation of potency of antibiotics by means of microbiological methods – preparation of pharmacopoeial antibiotic modules

Wstęp i cel pracy: Produkty lecznicze zawierające antybiotyki stanowią ważną i złożoną grupę preparatów terapeutycznych. Jednym z najważniejszych parametrów jest oznaczenie aktywności przeciwdrobnoustrojowej metodami mikrobiologicznymi, czyli określenie mocy antybiotyków. Wartość ta jest oznaczana w oparciu o odpowiednie wzorce. Zakład Antybiotyków i Mikrobiologii Narodowego Instytutu Leków (NIL) w ramach międzylaboratoryjnych badań biegłości, od 2000 roku uczestniczy w wyznaczaniu mocy nowych farmakopealnych wzorców antybiotyków. Badania organizowane są przez Europejski Dyrektoriat ds. Jakości Leków (EDQM) – Komisję Farmakopei Europejskiej, a uzyskane wyniki są analizowane statystycznie i opracowywane w formie raportów. Celem pracy było przedstawienie wyników badań dotyczących wyznaczania mocy wzorców antybiotyków. Materiał i metody: Oznaczano moc substancji – kandydatów na wzorce, następujących antybiotyków: amfoterycyna B, bacytracyna cynkowa, dihydrostreptomycyna, erytromycyna, kolistyna siarczan, kolistymetat sodowy, nystatyna, polimyksyna B siarczan, ryfamycyna sodowa i spiramycyna. Moc antybiotyków oznaczana jest przez porównanie zahamowania wzrostu wrażliwych drobnoustrojów standardowych przez badany antybiotyk i substancję porównawczą w znanym stężeniu. W badaniach stosowano zalecane przez farmakopee wrażliwe na badane antybiotyki drobnoustroje testowe z kolekcji ATCC. Moc antybiotyków określano przy zastosowaniu farmakopealnych metod mikrobiologicznych, głównie metody dyfuzyjnej, a w przypadku oznaczania mocy ryfamycyny sodowej również metody turbidymetrycznej. Badania prowadzone były w sposób umożliwiający przeprowadzenie walidacji matematycznego modelu równania mocy. Wyniki: Oznaczono moc mikrobiologiczną 14 substancji przyjętych następnie jako wzorce 10 różnych antybiotyków z bardzo dobrą precyzją: + / - 1 odchylenie standardowe (tylko w 2 przypadkach + / - 2 SD) od wartości średniej uzyskanej ze wszystkich laboratoriów biorących udział w badaniach biegłości. Wartość średnia została przyjęta przez EDQM jako oficjalna moc biologiczna dla danej serii wzorca. Wnioski: Oznaczenia mocy różnorodnych antybiotyków w Zakładzie Antybiotyków i Mikrobiologii NIL, według akredytowanej metody farmakopealnej, przeprowadzane jest na bardzo wysokim poziomie, uznanym przez EDQM przyznaniem atestu.Introduction and objective: Medicinal products containing antibiotics constitute an important and complex group of therapeutic preparations. One of the most important parameters is estimating the antimicrobial activity by means of microbiological methods, or assessing the potency of antibiotics, with reference to proper standards. The Department of Antibiotics and Microbiology of the National Medicines Institute (NMI) has participated in inter-laboratory proficiency tests aimed at estimating the potency of new pharmacopoeial antibiotic modules since 2000. The tests are conducted by the European Directorate for the Quality of Medicines (EDQM) – European Pharmacopoeia Commission, and the results are analyzed and drawn up in report form. The aim of this paper is to present the results of estimating the potency of antibiotic modules. Materials and methods: The potency of substances, prospective modules, of the following antibiotics was estimated: amphotericin B, bacitracin zinc, dihydrostreptomycin, erythromycin, colistin sulphate, colistimethate sodium, nystatin, polymyxin B sulphate, rifamycin sodium and spiramycin. The potency of antibiotics is estimated by comparing the inhibition of growth of sensitive standard micro-organisms produced by known concentrations of the examined antibiotic and a reference substance. The test micro-organisms sensitive to the examined antibiotics were recommended by pharmacopoeia and were supplied by the American Type Culture Collection (ATCC). The potency of antibiotics was estimated by means of pharmacopoeial microbiological methods, mainly a diffusion method, and a turbidimetric method in case of estimating the potency of rifamycin sodium. The examination was conducted in a way which permitted the validation of the mathematical model on which the power equation is based. Results: The microbiological potency of 14 substances was determined. The substances were then accepted as modules of 10 different antibiotics with high precision: + / - one standard deviation (SD) (in only two cases + / - 2 SD) of the average value received from all laboratories taking part in proficiency tests. The average value was accepted by the EDQM as the official biological potency for a given module batch. Conclusions: The estimation of the potency of a variety of antibiotics in the Department of Antibiotics and Microbiology of the NMI by means of an accredited pharmacopoeial method is a high-level scheme approved by the EDQM

How to Improve Health with Biological Agents—Narrative Review

The proper functioning of the human organism is dependent on a number of factors. The health condition of the organism can be often enhanced through appropriate supplementation, as well as the application of certain biological agents. Probiotics, i.e., live microorganisms that exert a beneficial effect on the health of the host when administered in adequate amounts, are often used in commonly available dietary supplements or functional foods, such as yoghurts. Specific strains of microorganisms, administered in appropriate amounts, may find application in the treatment of conditions such as various types of diarrhoea (viral, antibiotic-related, caused by Clostridioides difficile), irritable bowel syndrome, ulcerative colitis, Crohn’s disease, or allergic disorders. In contrast, live microorganisms capable of exerting influence on the nervous system and mental health through interactions with the gut microbiome are referred to as psychobiotics. Live microbes are often used in combination with prebiotics to form synbiotics, which stimulate growth and/or activate the metabolism of the healthy gut microbiome. Prebiotics may serve as a substrate for the growth of probiotic strains or fermentation processes. Compared to prebiotic substances, probiotic microorganisms are more tolerant of environmental conditions, such as oxygenation, pH, or temperature in a given organism. It is also worth emphasizing that the health of the host may be influenced not only by live microorganisms, but also by their metabolites or cell components, which are referred to as postbiotics and paraprobiotics. This work presents the mechanisms of action employed by probiotics, prebiotics, synbiotics, postbiotics, paraprobiotics, and psychobiotics, together with the results of studies confirming their effectiveness and impact on consumer health

The Impact of Efflux Pump Inhibitors on the Activity of Selected Non-Antibiotic Medicinal Products against Gram-Negative Bacteria

The potential role of non-antibiotic medicinal products in the treatment of multidrug-resistant Gram-negative bacteria has recently been investigated. It is highly likely that the presence of efflux pumps may be one of the reasons for the weak activity of non-antibiotics, as in the case of some non-steroidal anti-inflammatory drugs (NSAIDs), against Gram-negative rods. The activity of eight drugs of potential non-antibiotic activity, active substance standards, and relevant medicinal products were analysed with and without of efflux pump inhibitors against 180 strains of five Gram-negative rod species by minimum inhibitory concentration (MIC) value determination in the presence of 1 mM MgSO4. Furthermore, the influence of non-antibiotics on the susceptibility of clinical strains to quinolones with or without PAβN (Phe-Arg-β-naphthylamide) was investigated. The impacts of PAβN on the susceptibility of bacteria to non-antibiotics suggests that amitriptyline, alendronate, nicergoline, and ticlopidine are substrates of efflux pumps in Gram-negative rods. Amitriptyline/Amitriptylinum showed the highest direct antibacterial activity, with MICs ranging 100–800 mg/L against all studied species. Significant decreases in the MIC values of other active substances (acyclovir, atorvastatin, and famotidine) tested with pump inhibitors were not observed. The investigated non-antibiotic medicinal products did not alter the MICs of quinolones in the absence and in the presence of PAβN to the studied clinical strains of five groups of species

The Influence of Efflux Pump Inhibitors on the Activity of Non-Antibiotic NSAIDS against Gram-Negative Rods.

BACKGROUND:Most patients with bacterial infections suffer from fever and various pains that require complex treatments with antibiotics, antipyretics, and analgaesics. The most common drugs used to relieve these symptoms are non-steroidal anti-inflammatory drugs (NSAIDs), which are not typically considered antibiotics. Here, we investigate the effects of NSAIDs on bacterial susceptibility to antibiotics and the modulation of bacterial efflux pumps. METHODOLOGY:The activity of 12 NSAID active substances, paracetamol (acetaminophen), and eight relevant medicinal products was analyzed with or without pump inhibitors against 89 strains of Gram-negative rods by determining the MICs. Furthermore, the effects of NSAIDs on the susceptibility of clinical strains to antimicrobial agents with or without PAβN (Phe-Arg-β-naphtylamide) were measured. RESULTS:The MICs of diclofenac, mefenamic acid, ibuprofen, and naproxen, in the presence of PAβN, were significantly (≥4-fold) reduced, decreasing to 25-1600 mg/L, against the majority of the studied strains. In the case of acetylsalicylic acid only for 5 and 7 out of 12 strains of P. mirabilis and E. coli, respectively, a 4-fold increase in susceptibility in the presence of PAβN was observed. The presence of Aspirin resulted in a 4-fold increase in the MIC of ofloxacin against only two strains of E. coli among 48 tested clinical strains, which included species such as E. coli, K. pneumoniae, P. aeruginosa, and S. maltophilia. Besides, the medicinal products containing the following NSAIDs, diclofenac, mefenamic acid, ibuprofen, and naproxen, did not cause the decrease of clinical strains' susceptibility to antibiotics. CONCLUSIONS:The effects of PAβN on the susceptibility of bacteria to NSAIDs indicate that some NSAIDs are substrates for efflux pumps in Gram-negative rods. Morever, Aspirin probably induced efflux-mediated resistance to fluoroquinolones in a few E. coli strains

The Contribution of Efflux Systems to Levofloxacin Resistance in <i>Stenotrophomonas maltophilia</i> Clinical Strains Isolated in Warsaw, Poland

Levofloxacin is considered an alternative treatment option of Stenotrophomonas maltophilia infections to trimethoprim/sulfamethoxazole. The fluoroquinolone resistance in S. maltophilia is usually caused by an overproduction of efflux pumps. In this study, the contribution of efflux systems to levofloxacin resistance in S. maltophilia clinical isolates was demonstrated using phenotypic (minimal inhibitory concentrations, MICs, of antibiotics determination ± efflux pump inhibitors, EPIs) and molecular (real-time polymerase-chain-reaction and sequencing) methods. Previously, the occurrence of genes encoding ten efflux pumps was shown in 94 studied isolates. Additionally, 44/94 isolates demonstrated reduction in susceptibility to levofloxacin. Only 5 of 13 isolates (with ≥4-fold reduction in levofloxacin MIC) in the presence of EPIs showed an increased susceptibility to levofloxacin and other antibiotics. The overexpression of smeD and smeV genes (in five and one isolate, respectively) of 5 tested efflux pump operons was demonstrated. Sequencing analysis revealed 20–35 nucleotide mutations in local regulatory genes such as smeT and smeRv. However, mutations leading to an amino acid change were shown only in smeT (Arg123Lys, Asp182Glu, Asp204Glu) for one isolate and in smeRv (Gly266Ser) for the other isolate. Our data indicate that the overproduction of the SmeVWX efflux system, unlike SmeDEF, plays a significant role in the levofloxacin resistance