Epidemiology of neonatal sepsis in two neonatal intensive care units in Krakow, Poland in 2016-2017 years.

BACKGROUND: Sepsis in low-birth-weight neonates remains one of the most significant causes of neonatal morbidity and mortality. Approximately 3 million newborns suffer from sepsis globally every year. The aim of this study was to compare demographic and clinical features, as well as etiology and antibiotic susceptibility, of the main pathogens related to neonatal sepsis in two neonatal intensive units during a two-year period. METHODS: We observed early-onset (EO-BSI) and late-onset bloodstream infections (LO-BSI) cases in two high-reference neonatal intensive care units (NICU) over a 24-month period (2016-2017). Samples of patients' blood were tested for the presence of the microorganisms. All bacterial isolates were tested for susceptibility to antibiotics. RESULTS: The majority of sepsis cases weighed above 1000 g and were born by cesarean section. About 10% of the EO-BSI group died. There were differences in the EO-BSI /LO-BSI ratio in the compared wards due to differences among the admitted children. The most common pathogens isolated from blood were coagulase-negative staphylococci (CoNS) were represented by two dominating species: S. epidermidis and S. haemolyticus, followed by Klebsiella spp. strains and E.coli, which were mostly found in EO-BSI cases. No single S. agalactiae (GBS) strain was isolated. The majority of CoNS strains were resistant to methicillin, half were resistant to aminoglycosides, and one-third were resistant to macrolides and lincosamides. Half of the Gram-negative rods were resistant to beta-lactams. CONCLUSIONS: The epidemiology of sepsis in two observed NICUs is comparable to data obtained from other studies with a predominance of methicillin-resistant CoNS in LO-BSI and beta-lactam resistant E. coli in EO-BSI. It is of importance that the campaign for controlling GBS carriage in pregnant women in Poland resulted in the disappearance of GBS as a cause of sepsis. Unfortunately, there are no such measures to control E.coli related sepsis.

Urinary neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, uromodulin, and cystatin C concentrations in an experimental rat model of ascending acute kidney injury induced by pyelonephritis.

Recent evidence suggests that neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), cystatin C (CysC), uromodulin (UMOD), and some interleukins (IL-6 and IL-18) can be considered as diagnostic markers of acute kidney injury (AKI). The aim of this study was to verify the applicability of four urinary (u) markers, namely uNGAL, uKIM-1, uCysC, and uUMOD, for the diagnosis of ascending AKI induced by bacterial pyelonephritis. The study included 30 female rats that were divided into three groups (n = 10 each) and were inoculated transurethrally with various doses of Escherichia coli to induce isolated pyelonephritis (group 1, 105 CFU/ml), pyelonephritis-induced AKI (group 2, 107 CFU/ml), or AKI and urosepsis (group 3, 109 CFU/ml). The inoculate contained a highly virulent E. coli strain isolated from a patient with pyelonephritis. Urine samples were obtained prior to the inoculation and 7, 14, and 21 days thereafter. The concentrations of all assessed proteins were determined in the urine samples by ELISA. All the study groups showed elevated concentrations of uNGAL and uCysC at all study time points. The concentrations of uKIM-1 in group 1 were the same as that at the baseline, whereas it was elevated in groups 2 and 3 at all study time points. The concentrations of uUMOD in groups 1 and 2 tended to decrease with the time from inoculation, whereas it rapidly increased in group 3 at 21 days postinfection. uKIM-1 seems to be the only marker of ascending AKI associated with urinary tract infection. Elevated concentrations of uNGAL, uCysC, and uUMOD were found in both AKI and isolated pyelonephritis. Thus, it can be concluded that none of these markers can be used as a single diagnostic marker of ascending AKI, as it may produce false-negative results, leading to incorrect diagnosis, lack of adequate treatment, and increased mortality risk.

Clinical and microbiological aspects of the use of Lactobacillus rhamnosus PL1 strains in proctological patients with symptoms of chronic proctitis.

Recurrent proctitis and the symptoms associated therewith pose significant clinical problem in proctological patients. The objective of this study was to assess the impact of the probiotic Lactobacillus rhamnosus PL1 strain on the clinical presentation and composition of intestinal microbiota in patients with symptoms of proctitis in the course of hemorrhoidal disease and diverticulosis. Material consisted of 24 patients in whom no complete clinical improvement could be obtained after the treatment of the underlying disease. Subject to the assessment was the presence and the intensity of clinical symptoms as well as qualitative and quantitative changes in the composition of bacterial flora detected in the stool before, during and after a 9-week supplementation with the probiotic Lactobacillus rhamnosus PL1 strain. RESULTS: In the entire study group, the intensity of pain after 12 weeks was significantly lower (p=0,.011) compared to baseline; the intensity of flatulence and abdominal discomfort was reduced significantly as early as after 3 weeks, with the difference reaching a highly significant level after 12 weeks (pP<0,.0001). No significant difference was observed in the frequency of the reported episodes of diarrhea, constipation, as well as itching and burning in the anal region. As early as after 3 weeks of supplementation with the probiotic L. rhamnosus PL1 strain, significant qualitative and quantitative changes were observed in the composition of intestinal microbiota; the changes differed depending on the underlying disease. An increase in the total counts of the bacteria of Lactobacillus genus, particularly L. rhamnosus PL1 strain was observed regardless of the underlying disease. CONCLUSION: Tthe probiotic Lactobacillus rhamnosus PL1 strain appears to be useful in restoring appropriate ratios of bacterial populations in patients presenting with symptoms of proctitis in the course of the treatment of certain diseases of the lower gastrointestinal tract.

The virulence factors of group A streptococcus strains isolated from invasive and non-invasive infections in Polish and German centres, 2009-2011.

Streptococcus pyogenes (GAS) is one of the major human pathogenic bacteria that cause a wide range of diseases. Currently, increased incidence of streptococcal invasive infections is observed worldwide. In this study, we focused on the prevalence of genes encoding superantigens and type M proteins in the population of GAS strains from invasive versus non-invasive infections. We tested 253 GAS strains: 48 strains from patients with invasive infections (18 from wound/deep skin localization, 30 from women in labour) and 205 strains from non-invasive forms (147 from common infections of the upper respiratory, 49 from the vagina of females with genital tract infections and 9 from non-invasive wound and superficial skin infections). Significant differences were found in the occurrence of genes: speG, speI, speJ and smeZ, which were more common in GAS isolated from invasive than from non-invasive strains; speJ and smeZ occurred more frequently in strains from invasive perinatal infections versus strains from women without symptoms of invasive infection; speH and speI in strains from invasive skin/wound infection versus strains isolated from non-invasive wound and superficial skin infections. Emm types 1 and 12 predominated in the group of strains isolated from superficial infections and type 28 in those from puerperal fever. Occurrence of genes encoding virulence factors is common in genomic DNA of most of S. pyogenes, regardless whether these streptococcal infections are invasive or non-invasive. On the other hand, it appears that strains with speG, speI, speJ and smeZ genes may have a particular potential for virulence.

Virulence factors of Streptococcus pyogenes strains from women in peri-labor with invasive infections.

Invasive group A streptococcal (GAS) infections constitute an important epidemiological problem. Many cases occur in women during the postnatal period. The objective of this study was to evaluate the presence of the genes responsible for production of iron-chelating protein (perR) and superantigens (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, and ssa) in S. pyogenes strains isolated from invasive infections in women after delivery. Furthermore, this study sought to verify whether S. pyogenes strains show special phenotypic and genotypic (sla, spy1325) characteristics that may play a decisive role in adherence to the genital tract epithelium. Moreover, the emm-types and antibiotic susceptibility were determined. We tested 30 invasive S. pyogenes strains isolated from postpartum invasive infection and 37 GAS control strains isolated from the genital tracts of asymptomatic multiparous women. The majority of the tested strains were shown to express two types of emm genes (1 and 28), though emm -12, -28, -75 and -89 were uniquely expressed in the group of strains isolated from invasive infections. A significantly higher prevalence of perR in the strains from puerperal fever was shown. Significant differences were also found between the two groups with respect to the incidence of the genes related to adherence; GAS strains originating from women with sepsis/puerperal fever showed presence of these genes less frequently than those of the control group. Although differences in frequencies of the gene coding for various superantigens were noted between the compared groups of GAS strains, they were not significant.

Microbiological investigation of a hospital outbreak of invasive group A streptococcal disease in Krakow, Poland.

The present study reports the epidemiological investigations undertaken in one of Krakow's city hospitals regarding the source of infection and the routes of transmission of a group A streptococcus (Streptococcus pyogenes), using fluorescent in situ hybridization as a rapid method for detecting S. pyogenes carriage in the medical personnel involved. Four patients from the gynaecology department and two patients from the surgery department presented with clinical signs of infection. Characteristics of the S. pyogenes strains isolated from patients and from one medical staff member, including the emm gene and superantigens encoding genes, are described. All patients (four confirmed and two probable cases) survived; the operating theatre aid was identified as an S. pyogenes carrier and the source of the infections.

A role of hydrogen peroxide producing commensal bacteria present in colon of adolescents with inflammatory bowel disease in perpetuation of the inflammatory process.

Bacteria in the gut play a central role in the initiation and progress of inflammatory bowel disease (IBD). This study was prepared to elucidate the role in the inflammatory process of the bacterial species which are able to produce hydrogen peroxide, present in samples taken from colon lesions in adolescents with inflammatory bowel disease. Fifty eight adolescents were enrolled into the study from January 2004 to October 2006 in Cracow, Poland. Biopsies and stool samples were collected. Bacteriological examinations and measurements of hydrogen peroxide production by enterococci, streptococci and lactobacilli were performed. For the first time it has been shown here that HP producing bacteria may contribute to increased amounts of hydrogen peroxide in the inflamed mucosa of Crohn's disease and ulcerative colitis patients. Moreover, we have been able to demonstrate an increase of total populations of aerobic bacteria but not anaerobes in the studied samples of mucosa of adolescents with inflammatory bowel disease which is an indirect evidence of higher oxygen tension present in inflamed tissues in IBD. We have also been able to demonstrate the direct relationship between presence of blood in stools of IBD adolescents and increased populations of Enterobacteriaceae but not streptococci in samples of colon mucosa. It is, therefore, possible that different products of Enterobacteriaceae and especially their lipopolysaccharides may also contribute to perpetuation of the chronic colon inflammation.

Effect of hydrogen peroxide of bacterial origin on apoptosis and necrosis of gut mucosa epithelial cells as a possible pathomechanism of inflammatory bowel disease and cancer.

A series of in vitro experiments was arranged to assess effects of different concentrations of H(2)O(2) contained in bacterial cultures on apoptosis and necrosis of HT-29 line cells representing human gut epithelium. On the basis of cytofluorimetric assays it was possible to demonstrate that supernatant of the Lactobacillus strain producing hydrogen peroxide (L. delbrueckii CU/22) was able to induce both apoptosis and necrosis in human epithelial culture cells HT-29. Both effects were more prominent than those visible under influence of supernatant of the non-H(2)O(2)-producing Lactobacillus strain or chemically pure H(2)O(2) at the same concentration used as a control. In the light of this study and also other reports on damaging effects of hydrogen peroxide and superoxide radicals of bacterial origin on colonic cells, commensal bacteria of the human gut producing H(2)O(2) may be involved in pathomechanisms of IBD by perpetuating the inflammatory reaction and increasing apoptosis and necrosis. There is a promise that probiotic preparations containing Lactobacillus bacteria will be successful as adjunct therapy of IBD and it is, therefore, postulated to make a very careful selection of the Lactobacillus strains as candidates for probiotics indicated to ameliorate the course of IBD, before starting clinical trials.

Peeling force spectroscopy: exposing the adhesive nanomechanics of one-dimensional nanostructures.

The physics of adhesion and stiction of one-dimensional nanostructures such as nanotubes, nanowires, and biopolymers on different material substrates is of great interest for the study of biological adhesion and the development of nanoelectronics and nanocomposites. Here, we combine theoretical models and a new mode in the atomic force microscope to investigate quantitatively the physics of nanomechanical peeling of carbon nanotubes and nanocoils on different substrates. We demonstrate that when an initially straight nanotube is peeled from a surface, small perturbations can trigger sudden transitions between different geometric configurations of the nanotube with vastly different interfacial energies. This opens up the possibility of quantitative comparison and control of adhesion between nanotubes or nanowires on different substrates.

Differential inflammatory mediator response in vitro from murine macrophages to lactobacilli and pathogenic intestinal bacteria.

Chronic active colitis (including inflammatory bowel disease - IBD) is maintained by a variety of pro-inflammatory mediators. Certain intestinal bacterial strains may induce colitis, whereas some strains (e.g. Lactobacillus spp.) show a protective effect in colitis owing to their anti-inflammatory activity. In this study, we have examined the production of selected inflammatory cytokines, reactive oxygen species (ROS), nitric oxide (NO) and the expression of haeme oxygenase-1 (HO-1) by murine peritoneal macrophages stimulated in vitro by the intestinal bacterial strains, isolated from mice with colitis. Lactobacillus strains (Lactobacillus reuteri, L. johnsonii, L. animalis/murinus) and two potentially pathogenic bacteria (Escherichia coli and Enterococcus faecalis) induced the production of substantial amounts of cytokines with a strain specific profile. Despite some interstrain differences, all lactobacilli induced production of anti-inflammatory cytokines (IL-10(high), IL-6(low), IL-12p70(low)). Conversely, E. faecalis and E. coli induced the production of proinflammatory cytokines (TNF-alpha, IL-12p70), the cytokines essential for chronic IBD. Macrophages released comparably substantial amounts of ROS in response to all Lactobacillus strains tested, while E. coli and E. faecalis ability to induce generation of ROS was negligible. In contrast to ROS, the production of NO/NO(2) (-) by macrophages activated with all bacterial strains tested was similar. Moreover, for the first time, it has been shown that intestinal bacteria differed in their ability to induce expression of HO-1, a stress-inducible enzyme with antioxidant and anti-inflammatory properties. The beneficial immunoregulatory properties of candidate probiotic bacteria for the treatment of IBD are discussed.

Treatment of acute infectious diarrhoea in infants and children with a mixture of three Lactobacillus rhamnosus strains--a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Multiple studies document that probiotics are effective in treating infectious diarrhoea in children. Lactobacillus rhamnosus GG is the most extensively studied but effectiveness of other strains has been poorly examined. AIM: To determine whether L. rhamnosus strains (573L/1; 573L/2; 573L/3) (Lakcid L, Biomed, Lublin, Poland) would be effective in shortening infectious diarrhoea. METHODS: In a randomized, double-blind, placebo-controlled trial, 87 children (age range: 2 months to 6 years) with infectious diarrhoea were administered Lakcid L at a dose 1.2 x 10(10) CFU or placebo, twice daily, for 5 days. Primary outcome measure was the duration of diarrhoea. Secondary measures were duration of parenteral rehydration, adverse events, and gastrointestinal tract colonization by administered strains. RESULTS: In an intention to treat analysis of 87 children, the mean duration of diarrhoea in the treated group: 84 +/- 56 h; placebo: 96 +/- 72 h (P = 0.36). In rotavirus infection: 76 +/- 35 h vs. 115 +/- 67 h (P = 0.03), respectively. Duration of parenteral rehydration: 15 +/- 14 h vs. 38 +/- 33 h (P = 0.006). Gut colonization by administered strains was 80% and 41% at five and 14 days, respectively. No adverse events were noted. CONCLUSIONS: Administration of L. rhamnosus strains shortens the duration of rotaviral diarrhoea in children but not of diarrhoea of any aetiology. Intervention shortens the time of intravenous rehydration.

Critical evaluation of probiotic activity of lactic acid bacteria and their effects.

Probiotics discussed in this paper are evaluated using the WHO/FAO definition from 2001. The authors present a brief description of the normal microbiota of the gastrointestinal tract, discuss probiotics in the aspects of gut immunity and then move to selection of bacterial strains as probiotics. The main issue raised is the critical evaluation of probiotics in randomized clinical trials for conditions such as: infectious diarrhoea; antibiotic associated diarrhoea; inflammatory bowel disease; pouchitis and diverticulitis; H. pylori infection; irritable bowel syndrome. Safety of probiotics is mentioned with respect to susceptible individuals and bacterial translocation. As a conclusion the authors again recall the strain specific actions of probiotics in different clinical situations and that so far probiotics play a role in rotaviral and post antibiotic diarrhoea and pouchitis. An important issue still to be solved in order to confidently recommend probiotics as efficacious therapy is the regulatory aspect of probiotics.

[Antagonistic activity of Lactobacillus bacteria strains against anaerobic gastrointestinal tract pathogens (Helicobacter pylori, Campylobacter coli, Campylobacter jejuni, Clostridium difficile)]. / Antagonistyczne dzialanie bakterii z rodzaju Lactobacillus wobec beztlenowych i mikroaerofilnych czynników zakazen przewodu pokarmowego (Helicobacter pylori, Campylobacter coli, Campylobacter jejuni, Clostridium difficile).

Antagonistic activity of Lactobacillus strains has been known for some time. This property is connected with production of many active substances by lactobacilli e.g., organic acids and bacteriocin-like substances which interfere with other indigenous microorganisms inhabiting the same ecological niche, including also anaerobic gastrointestinal tract pathogens. Growing interest of clinical medicine in finding new approaches to treatment and prevention of common inflammatory infections of the digestive tract resulted in studies on a possible usage of lactic acid bacteria. Last years, several in vitro and in vivo experiments on antagonism of different Lactobacillus strains against Helicobacter pylori and Clostridium difficile were performed. These observations had been done on already established, well known probiotic Lactobacillus strains. We tested antibacterial activities of Lactobacillus strains isolated from human digestive tract. As indicator bacteria, four species known as anaerobic bacterial etiologic agents of gastroenteric infections: Helicobacter pylori, Campylobacter jejuni, C. coli and Clostridium difficile were used. Some of them were obtained from international collections, others were clinical isolates from specimens taken from patients with different defined gastrointestinal infections. We used a slab method of testing inhibitory activity described in details previously. Following conclusions were drawn from our study: All tested human Lactobacillus strains were able to inhibit the growth of all strains of anaerobic human gastrointestinal pathogens used in this study. Inhibitory activities of tested Lactobacillus strains against Helicobacter pylori, Campylobacter spp., and Clostridium difficile as measured by comparing mean diameters of the inhibition zones were similar. Differences in susceptibility of individual indicator strains of Campylobacter spp. and Clostridium difficile to inhibitory activity of Lactobacillus strains were small. A similar mechanism of inhibition of anaerobic bacteria by lactobacilli is postulated.

[Surface properties of Lactobacillus strains. I. Hemagglutination and hydrophobicity]. / Wlasciwosci powierzchniowe bakterii z rodzaju Lactobacillus. I. Wlasciwosci hemaglutynacyjne i hydrofobowe.

Bacteria possess many surface membrane properties, both mechanical and biochemical, that allow them to interact with their environment These properties may affect a host in either positive (beneficial) or negative (pathological) ways. All surface properties of bacteria are yet unknown therefore we attempt to increase our knowledge regarding specific strains of lactobacilli, by examining the known properties including hemagglutination and hydrophobicity. The purpose of this study was to evaluate the cell surface properties of certain strains of Lactobacillus. These strains isolated from the human vagina and gastrointestinal tract were selected because of their antagonism toward aerobic and anaerobic bacterial pathogens. Part I discusses the hydrophobicity and hemagglutination abilities of these Lactobacillus strains.

[Surface properties of Lactobacillus strains. II. Adherence to tissue culture surfaces]. / Wlasciwosci powierzchniowe bakterii z rodzaju Lactobacillus. II. Adherencja do linii komórkowych.

In the second part of this study, we evaluated the adherence properties of specific strains of Lactobacillus isolated from both the human vagina and gastrointestinal tracts. Lactobacilli taken from the vagina and GI tract were tested for their adherence to A431 vaginal tissue, and to CaCo-2 cells taken from the gastrointestinal tract. The Lactobacillus strains with the most marked adherence to the respective cell lines were examined under the electron microscope. These images revealed the presence of a substance morphologically resembling slime, which probably possess unknown active properties.

[The range of antagonistic effects of Lactobacillus bacterial strains on etiologic agents of bacterial vaginosis]. / Zakres antagonistycznego dzialania bakterii z rodzaju Lactobacillus na czynniki etiologiczne waginozy bakteryjnej.

Bacterial vaginosis is caused by uncontrolled sequential overgrowth of some anaerobic bacteria: Gardnerella vaginalis, Prevotella bivia, Bacteroides spp., Peptostreptococcus spp., Mobiluncus sp. usually occurring in stable numbers in the bacterial flora of healthy women. On the other hand, different species of bacteria belonging to the genus Lactobacillus, most frequently L. plantarum, L. rhamnosus and L. acidophilus, form a group of aerobic bacteria dominating in the same environment. The diversity and density of their populations depend on the age and health conditions. Thanks to their antagonistic and adherence properties bacteria of the genus Lactobacillus can maintain a positive balance role in this ecosystem. The aim of this study was to assess the antagonistic properties of Lactobacillus strains isolated from the vagina of healthy women against most common agents of bacterial vaginosis. It was found that nearly all of the tested Lactobacillus strains exerted distinct antagonistic activity against anaerobic bacteria: Gardnerella vaginalis, Prevotella bivia and Peptostreptococcus anaerobius and quite a number also against Gram-negative rods, while only some of them were able to inhibit Gram-positive aerobic cocci as Enterococcus faecalis or Staphylococcus aureus.

[A new method for evaluation of the antagonistic action of bacterial lactic acid (LAB) on selected pathogenic indicator bacteria]. / Nowa metoda oceny antagonistycznego dzialania bakterii kwasu mlekowego (LAB) na wybrane, chorobotwórcze bakterie wskaznikowe.

A comparison was made of three methods: paper disc, double layer and a newly proposed agar slab techniques for testing antibacterial activity of Lactobacillus strains. Strains of indicator bacteria were selected from important pathogens of the human alimentary and genitourinary tract. The agar slab method, which is based on applying of slabs of MRS agar with overnight growth of the antagonistic bacteria to the surface of appropriate agar plates seeded with indicator bacteria, appeared to be the only method suitable for testing of aerobic and anaerobic fastidious bacteria. After testing of 27 Lactobacillus strains against 3 selected indicator bacteria: E. coli, Salmonella enteritidis and Staphylococcus aureus, calculating mean values and standard deviations for diameters of inhibitory zones and making variance analysis it was shown that in comparison to other methods the agar slab technique, although less sensitive than others, gave most consistent and reproducible results.

[The significance of lactic acid bacteria in treatment and prophylaxis of digestive tract disorders]. / Znaczenie bakterii kwasu mlekowego w leczeniu i profilaktyce schorzen przewodu pokarmowego.

Probiotic bacteria are used to treat disturbed intestinal microflora and increased gut permeability which are characteristic to many intestinal disorders. Examples include children with acute rotavirus diarrhoea, subjects with food allergy, subjects with colonic disorders and patients undergoing pelvic radiotherapy and sometimes changes associated with colon cancer development. In all such disease states altered intestinal microflora, impaired gut barrier and different types of intestinal inflammation are present. Successful probiotic bacteria are able to survive gastric conditions and colonise the intestine, at least temporarily, by adhering to the intestinal epithelium. Already existing preparations containing viable lactic bacteria of human origin appear to have value in restoring normal microbial functions and alleviating symptoms in some patients with gastrointestinal infection and other conditions. Current scientifically based research efforts world-wide are now focusing on the development of high quality products containing microorganisms preselected for specific probiotic characteristics.

[Action of physical agents on microorganisms]. / Mechanizymy dzialania czynników fizycznych na drobnoustroje.

Among numerous physical agents exerting their deleterious effect on microorganisms only a few have been applied to sterilisation or disinfection used for medical purposes. Temperature is the most important agent, which from one side in a very wide range enables supporting of metabolic processes of psycho-, mezo- and thermophilic microorganisms, but beyond these limits causes their death. High temperature induces at first damage of cytoplasmic membrane and then denaturation of RNA leading to death. On the other hand, a low temperature slowly decreasing below 0 degree C induces crystallisation of water in cells and destruction of cytoplasmic structures. Ultraviolet radiation causes mutations resulting in stopping of DNA replication in all forms of the microorganisms. The same way of the lethal activity is exerted by ionising radiation. Its kinetic energy induces mutations affecting not single bases but also whole operons making gene expression impossible. Gaseous plasma is a new physical agent applied recently to sterilisation. High frequency energy initiates generation of the plasma from hydrogen peroxide vapours in a high vacuum and creates reactive species particles from the vapours that collide and kill microorganisms. On the other hand, application of ultrasound radiation to killing of microorganisms needs for further studies because of a high variability depending upon used frequency and energy. It is not known, for example, if destruction of microorganisms by ultrasounds is related to a phenomenon of cavitation or thermal energy. Nevertheless, even a range of frequency and energy used in commercial microwave ovens kills vegetative cells of coliform rods in about 15 minutes.