American Type Culture Collection Isolates Research Articles

Antiamylase, Antilipase, Antimicrobial, and Cytotoxic Activity of Nonea obtusifolia (Willd.) DC. from Palestine.

Background Medicinal plants are widely used in many cultures, traditions, and civilizations worldwide. Plants with high contents of the valuable biological compounds can efficiently cure many diseases. This study is aimed at assessing, for the first time, the anti-α-amylase, antilipase, antimicrobial, and cytotoxic activities of Nonea obtusifolia (Willd.) DC. of five extracts from Palestine. Methods The antimicrobial activity was estimated using well diffusion method for N. obtusifolia plant of five extracts against eight ATCC (American Type Culture Collection) and clinical isolates. The cytotoxic effects for these extracts were evaluated against HeLa (cervical) carcinoma cells using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Moreover, the lipase and α-amylase inhibitory properties were determined using standard biomedical assays. Results The acetone extract of N. obtusifolia plant showed a more potent α-amylase inhibitory compared with acarbose with IC50 values of 25.7 ± 0.08 and 28.18 ± 1.22 μg/ml, respectively. Additionally, the acetone and methanol extracts revealed moderate antilipase activity compared to orlistat with IC50 values of 30.19 ± 0.11, 33.11 ± 0.13, and 12.3 ± 0.35 μg/ml, respectively. The methylene chloride extract was found to inhibit the growth of all the tested bacterial and fungal strains and also found to have potential cytotoxic effect against HeLa cancer cell line. Conclusion This research work reports for the first time the biological activity of N. obtusifolia from Palestine, and the results were promising indicating that N. obtusifolia extracts contain valuable bioactive molecules that have a potential anti-α-amylase, antilipase, antibacterial, and antifungal cytotoxic potentials. Therefore, N. obtusifolia could have a medical significance in the future.

Antimicrobial and Synergistic Activity of 2,2',4-Trihydroxybenzophenone Against Bacterial Pathogens of Poultry.

In poultry farming, the spread of bacterial pathogens results in disease outbreaks causing significant economic losses to this industry. Many of these pathogenic bacteria are zoonotic and have a substantial impact on public health. Antimicrobials are essential for the prevention and treatment of these bacterial infections. However, the indiscriminate use of these agents provides favorable conditions for selection, propagation and persistence of bacteria and development of antimicrobial resistance. We developed a new antimicrobial candidate that could be used alone or in synergy with research protocols for therapeutic, prophylactic and growth promoter uses in the poultry industry. The present study aimed at evaluating the antimicrobial activity of the synthetic compound 2,2′,4-trihydroxybenzophenone against pathogenic bacteria that cause important diseases in poultry and public health. We tested the hemolytic effect of this compound, studied its synergistic effect with conventional antimicrobials and analyzed the site of action on the bacteria. The results of our study showed antimicrobial activity of benzophenone against Gram-positive and Gram-negative bacteria with a similar effect in ATCC (American type culture collection) and field isolates. This compound was non-hemolytic. 2,2′,4-trihydroxybenzophenone acted on the bacterial cell wall. We identified the synergistic effect between 2,2′,4-trihydroxybenzophenone and bacitracin, this effect indicate that antimicrobial synergism may be useful for the treatment of necrotic enteritis in poultry. This compound may also be used as a growth promoter by reducing the dose of bacitracin and thus decreasing the pressure of bacterial resistance in poultry which would circumvent the development of cross-resistance in humans.

Genetic Relatedness of Trichomonas vaginalis Reference and Clinical Isolates

We have determined the metronidazole susceptibility status of 20 Trichomonas vaginalis isolates from American Type Culture Collection (ATCC) and assessed the level of genetic relatedness in these isolates using 32 additional T. vaginalis clinical isolates for comparison. These ATCC isolates are commonly used as reference strains in T. vaginalis research and this information provides a rational basis for selection of reference strains for use in comparative studies of T. vaginalis phenotypic and clinical characteristics.

Mycoplasma contamination of Chlamydia pneumoniae isolates.

We examined 6 C. pneumonia isolates from The American Type Culture Collection (ATCC) and 2 Finnish isolates for Mycoplasma contamination. Three of the ATCC isolates and both of the Finnish isolates were Mycoplasma-contaminated. The contaminants were characterized by means of growth in BEa and BEg media, immunoblotting, polymerase chain reaction and pulsed field gel electrophoresis. Two of the 6 ATCC isolates [ATCC VR1355 (TWAR strain 2043) and ATCC VR1356 (TWAR strain 2023)] were infected with Mycoplasma hominis and 1 isolate [ATCC VR2282 (TWAR strain TW183)] was contaminated with both Mycoplasma hominis and Mycoplasma orale, whereas 3 of the ATCC isolates [ATCC VR1310, ATCC VR1360 (TWAR strain CM-1) and ATCC 53592 (TWAR strain AR39)] were not contaminated. The Finnish C. pneumoniae isolates Kajaani 6 and Parola were found to be contaminated with M. hominis and M. orale, respectively. The contamination of C. pneumoniae stock cultures, frequently used in the microimmunofluorescence test, with human pathogens, could pose a serious problem in C. pneumoniae serology.

Characterization of tetracycline and erythromycin resistance determinants in Treponema denticola.

Treponema denticola isolates were evaluated for the presence of known tetracycline and erythromycin resistance determinants by Southern blot hybridization of whole-cell DNA and PCR assays. We examined all isolates available, which included 12 clinical and 4 American Type Culture Collection isolates. Two isolates carried the Tet B determinant, five isolates carried both the Tet B and Erm F determinants, seven isolates carried the Erm F determinant, and two did not carry any of the Tet or Erm determinants tested. Both the Tet B and Erm F determinants appeared to be associated with the chromosome. Neither of the two T. denticola donors tested could transfer the Tet B determinant, but three of four T. denticola tested transferred the Erm F determinant to an Enterococcus faecalis recipient. This extends the host range of both the tetB and ermF genes into the genus Treponema.

Mitochondrial DNA fingerprinting of Acanthamoeba spp. isolated from clinical and environmental sources

Restriction fragment length polymorphism analysis of mitochondrial DNA (mtDNA fingerprinting) was evaluated as an epidemiologic tool for identifying potential reservoirs of Acanthamoeba infection. Fingerprints for 15 clinical isolates recovered by our affiliated laboratories were compared with those for 25 environmental isolates from western Washington State and 10 American Type Culture Collection (ATCC) strains. Seven different fingerprint groups emerged from the analysis of clinical isolates with six selected restriction enzymes (BamHI, BglII, EcoRI, HindIII, KpnI, and SalI). Fourteen (56%) environmental and 4 (40%) ATCC isolates displayed fingerprints similar to those of clinical isolates. In all, five of the seven groups contained one or more environmental and/or ATCC isolates. Comparisons with published mtDNA fingerprints for Acanthamoeba isolates showed that two groups have counterparts in Europe and Japan and in Europe and Australia. The inclusion of environmental isolates demonstrated that the most common clinical isolates do have counterparts readily recoverable from the surrounding environment and that some of these counterparts appear to be geographically widespread.

Stimulatory effect of cooling tower biocides on amoebae

Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds, another quaternary ammonium compound alone, and an isothiazolin derivative. The amoebae isolated were Acanthamoeba hatchetti and a Cochliopodium species. Two other amoeba cultures, an A. hatchetti culture and Cochliopodium bilimbosum, were obtained from the American Type Culture Collection (ATCC) and were also tested. The cooling tower isolates were more resistant to most of the biocides than the ATCC isolates were. The isothiazolin derivative was the least inhibitory to all four amoeba isolates, and tributyltin neodecanoate mixed with quaternary ammonium compounds was the most inhibitory to three of the four isolates. After exposure to lower concentrations of the biocides, including for one strain the manufacturer's recommended concentration of one biocide, the cooling tower amoeba populations increased significantly compared with unexposed controls, whereas the ATCC isolates were not stimulated at any of the concentrations tested. In some cases, concentrations which stimulated cooling tower amoebae inhibited the growth of the ATCC isolates. These results suggest that cooling tower amoebae may adapt to biocides, underscoring the need to use freshly isolated cooling tower organisms rather than organisms from culture collections for testing the efficacy of such biocides. The stimulatory effect of biocides on amoeba populations is an alarming observation, since these organisms may be reservoirs for legionellae. Biocides used to control microbial growth may actually enhance populations of host organisms for pathogenic bacteria.