The effect of mesenchymal stem cell conditioned medium incorporated within chitosan nanostructure in clearance of common gastroenteritis bacteria in-vitro and in-vivo.

Gastroenteritis infection is a major public health concern worldwide, especially in developing countries due to the high annual mortality rate. The antimicrobial and antibiofilm activity of human mesenchymal stem cell-derived conditioned medium (hMSCsCM) encapsulated in chitosan nanoparticles (ChNPs) was studied in vitro and in vivo against common gastroenteritis bacteria. The synthesized ChNPs were characterized using Zeta potential, scanning electron microscopy (SEM), and dynamic light scattering (DLS) techniques. HMSC-derived conditioned medium incorporated into chitosan NPs (hMSCsCM-ChNPs) composite was fabricated by chitosan nanoparticles loaded with BM-MSCs (positive for CD73 and CD44 markers). The antimicrobial and antibiofilm activity of composite was investigated against four common gastroenteritis bacteria (Campylobacter jejuni ATCC29428, Salmonella enteritidis ATCC13076, Shigella dysenteriae PTCC1188, and E. coli ATCC25922) in-vitro and in-vivo. Majority of ChNPs (96%) had an average particle size of 329 nm with zeta potential 7.08 mV. The SEM images confirmed the synthesis of spherical shape for ChNPs and a near-spherical shape for hMSCsCM-ChNPs. Entrapment efficiency of hMSCsCM-ChNPs was 75%. Kinetic profiling revealed that the release rate of mesenchymal stem cells was reduced following the pH reduction. The antibacterial activity of hMSCsCM-ChNPs was significantly greater than that of hMSCsCM and ChNPs at dilutions of 1:2 to 1:8 (P < 0.05) against four common gastroenteritis bacteria. The number of bacteria present decreased more significantly in the group of mice treated with the hMSCsCM-ChNPs composite than in the groups treated with hMSCsCM and ChNPs. The antibacterial activity of hMSCsCM against common gastroenteritis bacteria in an in vivo assay decreased from > 106 CFU/ml to approximately (102 to 10) after 72 h. Both in vitro and in vivo assays demonstrated the antimicrobial and antibiofilm activities of ChNPs at a concentration of 0.1% and hMSCsCM at a concentration of 1000 µg/ml to be inferior to that of hMSCsCM-ChNPs (1000 µg/ml + 0.1%) composite. These results indicated the existence of a synergistic effect between ChNPs and hMSCsCM. The designed composite exhibited notable antibiofilm and antibacterial activities, demonstrating optimal release in simulated intestinal lumen conditions. The utilization of this composite is proposed as a novel treatment approach to combat gastroenteritis bacteria in the context of more challenging infections.

Effects of Curcumin and Silymarin on the Shigella dysenteriae and Campylobacter jejuni In vitro.

OBJECTIVE: Antimicrobial properties of silymarin and curcumin have been assessed against several infectious agents. The aim of this study was to investigate the anti-apoptotic and antibacterial effects of both compounds on the expression of genes among Shigella dysenteriae ATCC 12022 and Campylobacter jejuni subsp. jejuni strain ATCC 33560 standard strains. METHODS: S. dysenteriae and C. jejuni standard strains were prepared from reference laboratory. Additionally, two clinical multidrug-resistant (MDR) isolates were adopted. Silymarin and curcumin stocks were purchased from Sigma Corporation (USA), and after preparation of dilutions (0.5-512 µg/ml), the minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) were determined. Furthermore, the effect of 100 µg/ml of each compound was also evaluated on the expression of two gyrB and 16S rRNA housekeeping genes by quantitative real-time PCR (qRT-PCR). RESULTS: Silymarin MIC and MBC were 512 µg/ml and > 512 µg/ml against S. dysenteriae and > 512µg/ml against C. jejuni standard strains, respectively. Moreover, curcumin MIC and MBC concentrations were 256 µg/ml and 512 µg/ml, respectively for ATCC strains. Silymarin down-expressed the expression of gyrB gene in S. dysenteriae and gyrB and 16srRNA gene in C. jejuni significantly (p < 0.05) compared with unexposed strains. In addition, curcumin could down-express the both gyrB and 16S rRNA genes in both strains significantly (p < 0.05). For two MDR clinical isolates, both MIC and MBC of compounds were > 512 µg/ml. Addition of 100 µg/ml curcumin and silymarin to ampicillin (10 µg/ml) lowered the MIC of MDR S. dysenteriae to 256 µg/ml and 512 µg/ml, respectively. However, no MIC change was observed with regard to C. jejuni. CONCLUSION: In this study, curcumin and silymarin could inhibit the growth of S. dysenteriae and C. jejuni and 100 µg/ml sub-MIC levels exhibited the suppression of housekeeping genes. Combating pathogenic bacteria by compounds alternative to antibiotics in the era of antibiotic resistance is a proper strategy, though more studies using combinations of them are needed.

Synthesis, characterization and use of iron oxide nano particles for antibacterial activity.

In this decade, the use of nano particles (NPs) against bacterial growth is increasing day by day due to remarkable alternative properties compared to molecular antibiotics. Thus, the use of iron oxide nanoparticles (IONPs) has proven one of the most important transition metals oxide-based remedy in nanotechnological advances and biological applications due to enriched biocompatibility of iron. In this study synthesis of IONPs was carried out via co-precipitation method. The crystallographic morphology of the synthesized particles was studied via X-ray diffraction which revealed cubic structure of the particles, whereas, the spinal shaped morphology of the prepared NPs was confirmed from scanning electron microscopy. Likewise, the presence of the major elements in the sample was determined through energy dispersive X-ray analysis characterization. Bactericidal effect of the NPs was assessed at pre-defined concentrations (50 and 100 µg/ml) against Gram +ve bacteria Staphylococcus aureus, Gram -ve bacteria Shigella dysentry and Escherichia coli. Bacterial strains, which demonstrate the potential of NPs. The purpose of this study was assessing the structure of the synthesized NPs for protective effect against harmful bacterial activity.

Effectiveness of aqueous and hydroalcoholic extracts of Acanthospermum australe (Loefl) Kuntze against diarrhea-inducing bacteria / Eficácia de extratos aquosos e hidroalcoólicos de Acanthospermum australe (Loefl) Kuntze contra bactérias indutoras de diarreia

Abstract Leaves and roots of Acanthospermum australe (Asteraceae) have been used in Brazilian folk medicine for the treatment of various ailments including diarrhea, skin diseases, blennorrhagia, dyspepsia, parasitic worms and malaria. The aim of study was to characterize the chemical profiles of the aqueous and hydroalcoholic extracts of leaves and roots of A. australe, and to evaluate their antimicrobial activities against diarrhea-inducing bacteria (Enterococcus faecalis, Shigella dysenteriae and Yersinia enterocolitica), as well as their cytotoxic properties. Aqueous leaf extracts were obtained by infusion, while aqueous root extracts were obtained by decoction. The hydroalcoholic leaf and root extracts were prepared by maceration in 90% ethanol for 3 days. Antimicrobial activity was assessed using standard techniques and cytotoxicity was evaluated using Chinese hamster ovary cells CHO-K1. Chemical analysis revealed the presence of tannins, flavonoids, saponins and phenolic compounds in the extracts. Although root extracts were not effective against E. faecalis, leaf extracts at concentrations of 20 mg/mL exhibited bactericidal activities against this microorganism. The hydroalcoholic root extract was unique in presenting a bactericidal effect against S. dysenteriae. None of the extracts showed bacteriostatic or bactericidal activities against Y. enterocolitica. The results presented herein demonstrate that the Gram-positive E. faecalis and the Gram-negative S. dysenteriae were susceptible to A. australe extracts, although bacteriostatic/bactericidal activities were only observed at concentrations considered too high for clinical application. Our results support the ethnopharmacological use of A. australe in the treatment of gastrointestinal disorders, particularly diarrhea caused by infectious bacteria, although further studies are required to determine the anti-diarrhea effects and the toxicities of the extracts in vivo.

Resumo Folhas e raízes de Acanthospermum australe (Asteraceae) têm sido usadas na medicina popular brasileira para o tratamento de várias doenças, incluindo diarreia, doenças de pele, blenorragia, dispepsia, vermes parasitas e malária. O objetivo deste estudo foi caracterizar os perfis químicos dos extratos aquosos e hidroalcoólicos das raízes e folhas de A. australe, e avaliar as suas atividades antimicrobianas contra as bactérias indutoras de diarreia (Enterococcus faecalis, Shigella dysenteriae e Yersinia enterocolitica), bem como sua citotoxicidade. Os extratos aquosos de folhas foram obtidos por infusão, enquanto que os extratos aquosos de raízes foram obtidos por decocção. Os extratos hidroalcoólicos de folhas e raízes foram preparados por maceração em etanol a 90% durante 3 dias. A atividade antimicrobiana foi avaliada utilizando técnicas padrão e a citotoxicidade foi avaliada utilizando células de ovário de hamster chinês CHO-K1. A análise química revelou a presença de taninos, flavonóides, saponinas e compostos fenólicos nos extratos. Apesar de extratos de raiz não foram eficazes contra E. faecalis, extratos de folhas em concentrações de 20 mg/mL apresentaram atividades bactericidas contra este microrganismo. O extrato hidroalcoólico de raiz foi o único a apresentar um efeito bactericida contra S. dysenteriae. Nenhum dos extratos apresentaram atividades bacteriostáticas ou bactericidas contra Y. enterocolitica. Os resultados apresentados demonstram que a bactéria Gram-positiva E. faecalis e a Gram-negativa S. dysenteriae foram suscetíveis aos extratos de A. australe, embora as atividades bacteriostáticos/bactericidas tenham sido apenas observados em concentrações consideradas elevadas para aplicação clínica. Os nossos resultados apoiam a utilização de etnofarmacológica de A. australe no tratamento de perturbações gastrointestinais, especialmente diarreia causadas por bactérias infecciosas, embora sejam necessários mais estudos para determinar os efeitos anti-diarreia e as toxicidades dos extratos in vivo.

Promotion of quality standard of Chinese herbal medicine by the integrated and efficacy-oriented quality marker of Effect-constituent Index.

BACKGROUND: Multiple constituents have been applied currently as markers to control the quality of Chinese herbal medicine (CHM). However, those constituents are isolated from each other, failed to present their contribution differences to the bioeffect of CHM. Besides, a CHM for different clinic uses is often controlled by the same quality marker (Q-marker), which cannot correlate its efficacies differentially. PURPOSE: The study aims to promote the quality standard of CHM by the integrated and efficacy-oriented Q-marker of Effect-constituent Index (ECI). METHODS: With Coptidis Rhizoma (C. Rhizoma) as a case study, the Q-marker of ECI based on the integration of bioeffect and active constituents was developed. According to the efficacies of C. Rhizoma, we investigated its antibacterial and antineoplastic effects by microcalorimetry and MTT assay, respectively. High performance liquid chromatography was performed to determine the active constituents of C. Rhizoma extract simultaneously. ECIS of inhibition on Shigella dysenteriae (S. dysenteriae) and ECIH of inhibition on HepG2 cells were established by multi-indicator synthetic evaluation method. The organoleptic evaluation scores of C. Rhizoma samples were given by Delphi method. RESULTS: The correlation analysis showed that ECIS and ECIH were significantly correlated with the inhibiting effects of C. Rhizoma extract on the growth of S. dysenteriae (P < 0.01) and proliferation of HepG2 cells (P < 0.01), respectively. Moreover, ECI showed a good ability to distinguish and predict the bioeffect-based quality grade, whereas the organoleptic evaluation and chemical analysis failed to achieve it. Plus, some samples with lower ECIS showed higher ECIH and vice versa. CONCLUSIONS: The Q-marker of ECI is useful to associate different pharmacologic effects of C. Rhizoma containing multiple active constituents, which is beneficial for the improvement of quality standard of the CHM in an integrated, convenient, and differentiated way.

Chemical Composition, Antioxidant, DNA Damage Protective, Cytotoxic and Antibacterial Activities of Cyperus rotundus Rhizomes Essential Oil against Foodborne Pathogens.

Cyperus rotundus L. (Cyperaceae) is a medicinal herb traditionally used to treat various clinical conditions at home. In this study, chemical composition of Cyperus rotundus rhizomes essential oil, and in vitro antioxidant, DNA damage protective and cytotoxic activities as well as antibacterial activity against foodborne pathogens were investigated. Results showed that α-cyperone (38.46%), cyperene (12.84%) and α-selinene (11.66%) were the major components of the essential oil. The essential oil had an excellent antioxidant activity, the protective effect against DNA damage, and cytotoxic effects on the human neuroblastoma SH-SY5Y cell, as well as antibacterial activity against several foodborne pathogens. These biological activities were dose-dependent, increasing with higher dosage in a certain concentration range. The antibacterial effects of essential oil were greater against Gram-positive bacteria as compared to Gram-negative bacteria, and the antibacterial effects were significantly influenced by incubation time and concentration. These results may provide biological evidence for the practical application of the C. rotundus rhizomes essential oil in food and pharmaceutical industries.

Transcriptional and posttranscriptional regulation of Shigella shuT in response to host-associated iron availability and temperature.

Like most bacteria, Shigella must maintain a precise balance between the necessity and toxicity of iron; a balance that is achieved, at least in part, by regulating the production of bacterial iron acquisition systems in response to specific environmental signals. Using the Shigella heme utilization (Shu) system, S. dysenteriae is able to acquire iron from heme, a potentially rich source of nutritional iron within the otherwise iron-limited environment of the human host. Investigations presented within reveal two distinct molecular mechanisms underlying previously uncharacterized transcriptional and translational regulation of shuT, a gene encoding the periplasmic-binding component of the Shu system. While shuT transcription is regulated in response to iron availability via a process dependent upon the global regulator Fur and a Fur-binding site located immediately downstream of the promoter, shuT translation is regulated in response to environmental temperature via the activity of an RNA thermometer located within the 5' untranslated region of the gene. Such complex regulation likely increases the fitness of S. dysenteriae by ensuring maximal ShuT production when the pathogen is within the iron-limited and relatively warm environment of the infected host, the only environment in which heme will be encountered as a potential source of essential iron.

Controlling the cytokine storm in severe bacterial diarrhoea with an oral Toll-like receptor 4 antagonist.

Shigella dysenteriae causes the most severe of all infectious diarrhoeas and colitis. We infected rhesus macaques orally and also treated them orally with a small and non-absorbable polypropyletherimine dendrimer glucosamine that is a Toll-like receptor-4 (TLR4) antagonist. Antibiotics were not given for this life-threatening infection. Six days later, the clinical score for diarrhoea, mucus and blood was 54% lower, colon interleukin-8 and interleukin-6 were both 77% lower, and colon neutrophil infiltration was 75% less. Strikingly, vasculitis did not occur and tissue fibrin thrombi were reduced by 67%. There was no clinical toxicity or adverse effect of dendrimer glucosamine on systemic immunity. This is the first report in non-human primates of the therapeutic efficacy of a small and orally bioavailable TLR antagonist in severe infection. Our results show that an oral TLR4 antagonist can enable controlled resolution of the infection-related-inflammatory response and can also prevent neutrophil-mediated gut wall necrosis in severe infectious diarrhoeas.

Purification, characterization, and biological activities of broccolini lectin.

Plant lectins have displayed a variety of biological activities. In this study, for the first time, a 27 kDa arabinose- and mannose-specific lectin from Broccolini (Brassica oleracea Italica × Alboglabra), named as BL (Broccolini lectin), was purified by an activity-driven protocol. Mass spectrometry analysis and database search indicated that no matches with any plant lectin were found, but BL contained some peptide fragments (QQQGQQGQQLQQVISR, QQGQQQGQQGQQLQQVISR and VCNIPQVSVCPF QK). BL exhibited hemagglutinating activity against chicken erythrocytes at 4 µg/mL. BL retained full hemagglutinating activity at pH 7-8 and temperature 30-40°C, and had an optimal activity in Ca(2+) solution. Bioactivity assay revealed that BL exhibited dose-dependent inhibition activity on 5 bacterial species with IC50 values of 143.95-486.33 µg/mL, and on 3 cancer cells with IC50 values of 178.82-350.93 µg/mL. Notably, 5-fold reduction in IC50 values was observed on normal L-O2 vs cancerous HepG-2 cells (924.35 vs. 178.82 µg/mL). This suggests that BL should be promising in food and medicine.

Oxalis corniculata (Oxalidaceae) leaf extract exerts in vitro antimicrobial and in vivo anticolonizing activities against Shigella dysenteriae 1 (NT4907) and Shigella flexneri 2a (2457T) in induced diarrhea in suckling mice.

In this study, the extract of a green leafy vegetable Oxalis corniculata (Oxalidaceae) was evaluated for its in vitro antibacterial and in vivo anti colonizing effect against common intestinal pathogenic bacteria. Methanolic extract (80%) of Oxalis corniculata (Oxalidaceae) leaf contained a polyphenol content of 910 mg gallic acid equivalent per gram of dry weight and the yield was 8%. The flavonoid content was 2.353 g quercetin equivalent per 100 g of the extract. In vitro studies indicated that the extract inhibited numerous pathogenic bacteria like Staphylococcus aureus (ATCC 25922), Escherichia coli (ATCC 25923), Shigella dysenteriae 1 (NT4907), Shigella flexneri 2a (2457T), Shigella boydii 4 (BCH612), and Shigella sonnie phase I (IDH00968). The minimum inhibitory concentration (MIC) against E. coli (ATCC 25923) was minimal (0.08 mg/mL), whereas MIC against S. flexneri 2a (2457T) was higher (0.13 mg/mL). A suckling mouse model was developed which involved challenging the mice intragastrically with S. flexneri 2a (2457T) and S. dysenteriae 1 (NT4907) to study the anticolonization activity. It was revealed that the extract was more potent against S. dysenteriae 1 (NT4907) as compared to S. flexneri 2a (2457T). It was also found that simultaneous administration of extract along with bacterial inoculums promoted good anticolonization activity. Significant activity was observed even when treated after 3 h of bacterial inoculation.

Antibacterial activity and in vitro anti-tumor activity of the extract of the larvae of the housefly (Musca domestica).

One of the significant characteristics of traditional Chinese medicine is the use of insects, other terrestrial arthropods and their products as drugs. In the present work, the extract of housefly (Musca domestica) larvae was studied by an agar well diffusion assay and minimum bactericidal concentration (MBC) determination for detection of antimicrobial activity and by MTT assay method to test its in vitro anti-tumor activity. In our studies, the extract inhibited six tested bacterial pathogens and Escherichia coli Jm109, a gene-modified strain resistant to ampicillin with the MBCs ranging from 200 to 1600 microg/ml, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The extract showed high in vitro anti-tumor activity against human colon cancer cell line CT26 with the IRs ranging from 62 to 89%. The extract of housefly larvae inoculated with Shigella dysenteriae 51302 exhibited higher antibacterial activity and in vitro anti-tumor activity than that of native larvae, which may indicate the same principle involved in the use of Bombyx mori larvae infected with silk moth fungus Beauveria bassiana and Hepialis larvae infected with Cordiceps fungus in the traditional Chinese medicine. Both extracts did not show any coagulation activity and haemolysis activity against rabbit erythrocytes at 500 and 1000 microg/ml. The results support its use in the traditional Chinese medicine, and warrant the further identification of the active molecule in the housefly larvae.

[Antibacterial action of ether oils of some plants].

Inhibitory effect of clove oil on Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Shigella dysenteriae and Candida albicans was detected. Mint ether oil had the high antibacterial action on S. aureus, however against other microorganisms mint oil had a reliably low effect then clove oil. Fennel oil had high antibacterial effect on C. albicans, and bactericidal action on S. typhimurium and S. dysenteriae.

Nutritive value, antioxidant and antimicrobial properties of Struchium sparganophora leaves.

Struchium sparganophora leaf is a green leafy vegetable popularly used in soup preparations in processed and unprocessed forms in Nigeria. Fresh leaves of S. sparganophora were soaked overnight to remove its bitterness, before determination of the nutrient and antinutrient content, while sun-dried S. sparganophora leaves were extracted with rectified spirit. The antioxidant and antimicrobial properties of the extracts were subsequently determined. The result of the study revealed that the fresh leaf has high nutrient (protein, fat, crude fiber, and mineral) but low antinutrient (tannin and phytate) content. However, processing of the S. sparganophora leaf caused a significant decrease (P < .05) in both the nutrient and antinutrient contents. The ethanolic extract of the leaf contains alkaloids, tannin, saponins, phlobatannin, anthraquinone, and glycosides; furthermore, the extract has high antioxidant activity as typified by its high total phenol (5.4 g/100 g) content, reducing power (2.50 OD(700)), and free radical scavenging ability (65.2%). In addition, the extract (1.0 mg/mL) inhibited the growth of some pathogenic bacteria [Shigella dysenteriae (zone of inhibition 17.0 mm), Staphylococcus aureus (11.0 mm)] and fungi [Candida albicans (18.0 mm), Penicillium sp. (14.0 mm), Saccharomyces cerevisiae (15.0 mm)]. The inhibition of the bacterial and fungal growth was dose dependent. However, the same concentration of the extract did not inhibit the growth of Escherichia coli, Proteus sp., Pseudomonas aeruginosa, and Klebsiella sp., as well as the growth of the following fungi: Aspergillus fumigatus, Fusarium solani, and Aspergillus flavus. It could therefore be inferred that the leaf of S. sparganophora is promising both nutritionally and medicinally because of its high nutrient content, low antinutrient content, and arrays of pharmaceutically active phytochemicals with high levels of antioxidant and antimicrobial activity.

Shigella dysenteriae ShuS promotes utilization of heme as an iron source and protects against heme toxicity.

Shigella dysenteriae serotype 1, a major cause of bacillary dysentery in humans, can use heme as a source of iron. Genes for the transport of heme into the bacterial cell have been identified, but little is known about proteins that control the fate of the heme molecule after it has entered the cell. The shuS gene is located within the heme transport locus, downstream of the heme receptor gene shuA. ShuS is a heme binding protein, but its role in heme utilization is poorly understood. In this work, we report the construction of a chromosomal shuS mutant. The shuS mutant was defective in utilizing heme as an iron source. At low heme concentrations, the shuS mutant grew slowly and its growth was stimulated by either increasing the heme concentration or by providing extra copies of the heme receptor shuA on a plasmid. At intermediate heme concentrations, the growth of the shuS mutant was moderately impaired, and at high heme concentrations, shuS was required for growth on heme. The shuS mutant did not show increased sensitivity to hydrogen peroxide, even at high heme concentrations. ShuS was also required for optimal utilization of heme under microaerobic and anaerobic conditions. These data are consistent with the model in which ShuS binds heme in a soluble, nontoxic form and potentially transfers the heme from the transport proteins in the membrane to either heme-containing or heme-degrading proteins. ShuS did not appear to store heme for future use.

Inhibition of prokaryotic translation by the Shiga toxin enzymatic subunit.

Shiga toxin, produced by Shigella dysenteriae serotype 1, is a member of the large family of ribosome-inactivating proteins (RIPs) which are primarily produced by plants. All RIPs are rRNA N-glycosidases which inactivate ribosomes through the removal of a specific adenine residue from the well-conserved aminoacyl-tRNA-accepting loop of rRNA. As a type II RIP, STX is believed to have little effect on prokaryotic ribosomes. However, we have demonstrated that over-expression of the STX enzymatic (A1) polypeptide which lacks a signal sequence caused a reduced rate of growth of its Escherichia coli host. Over-expression of the same StxA1 polypeptide with a catalytic site substitution had no effect on the growth of E. coli. In addition, purified StxA1 was an inhibitor of prokaryotic protein synthesis as assessed using an in vitro transcription and translation assay. The specific activity of StxA1 was significantly higher than ricin, which is another type II RIP, with both eukaryotic and prokaryotic translation systems.

Severe shigellosis in childhood.

A prospective study was performed on 20 bacteriologically proven pediatric cases of severe shigellosis admitted to the Department of Pediatrics, Chulalongkorn Hospital during March 1989 to March 1990. Fourteen patients were male and six were female. Shigella B was found in 85% and Shigella D in 15% of cases. The major indications for admission were convulsions and dehydration. Fifteen per cent of cases had underlying malignancies and 42.1% had malnutrition. Most patients had a peak of fever between 39.5 and 40.5 degrees C, serum sodium between 128-144 mEq/l. Mild acidosis was detected in 45% and moderate acidosis in 30% of cases. There were no statistical differences in peak of fever and serum sodium between patients who had convulsion and who did not. Shigellemia was found in one case who also had underlying neuroblastoma. One patient died due to necrotizing enterocolitis, septic shock and renal failure. Most of the organisms found resisted to ampicillin and trimethoprim-sulfamethoxazole (TMP-SMX). However, TMP-SMX was prescribed in most immunocompetent patients and they recovered well. All of three patients with underlying malignancy responded well to ceftriaxone.

Epidemias por salmonella y por shigella, importancia de la vigilancia epidemiologíca y control de la resistencia a los antibióticos / Epidemics by salmonella and shigella, importance of epidemiologic vigilance and control of the antibiotics resistence

El descubrimiento de los antibióticos y su aplicación clínica ha permitido el tratamiento y control de padecimientos infecciosos. Por otra parte, se ha descubierto que algunas enterobacterias desarrollan resistencia a las drogas antimocrobianas causada, principalmente por la presencia de elementos extracromosómicos denominados plasmidos. De entre estos microorganismos se han estudiado la salmonella y shigella con la finalidad de determinar las características de las mismas, los antibióticos a que se resisten y con cuales pueden ser tratados los padecimientos provocados por las mismas. La presencia de epidemias y las endemias en regiones de México así como en otras regiones del mundo, y consecuentemente el alto índice de morbilidad han inducido a los especialistas a investigar los procesos infecciosos provocados por shigella y la salmonella, se ha logrado establecer una clasificación de las mismas así como la sintomatología que producen las mismas. Para establecer un tratamiento determinado, se aisló al agente infeccioso, se le sometió a estudios para poder establecer a que drogas eran resistentes y a cuales no. De este modo se ha podido descrubir que algunos tipos de estas bacterias son resistentes, por ejemplo, al clorafenicol, la tetraciclina, la estreptomicina y a la ampicilina, en tanto que otras son suceptibles a los mismos, así mismo se ha observado que la región guarda cierta relación con el desarrollo de la resistencia

Combined effects of diphenyliodonium chloride, pine oils, and mustard oil soaps on certain microorganisms.

Bactericidal and bacteriostatic activities of an emulsion containing 10.0% (v/v) terpineol, 0.5% (w/v) diphenyliodonium chloride, 11.0% (v/v) ethyl alcohol, and 5.62% saponified mustard oil were tested against a number of different types of organisms. The bactericidal concentration for Salmonella typhosa was 1:400. In the presence of 5.0% horse serum, it increased to 1:250. The bacteriostatic concentration varied from organism to organism; Escherichia coli and Staphylococcus aureus required 4,000 mug/ml for complete bacteriostasis, whereas Corynebacterium diphtheriae, Salmonella paratyphi-A, and Shigella required only 2,000 mug/ml for complete inhibition. A 4.0% concentration of the emulsion killed the spores of Bacillus subtilis within 6 hr.