High prevalence of multidrug resistant ESBL- and plasmid mediated AmpC-producing clinical isolates of Escherichia coli at Maputo Central Hospital, Mozambique.

BACKGROUND: Epidemiological data of cephalosporin-resistant Enterobacterales in Sub-Saharan Africa is still restricted, and in particular in Mozambique. The aim of this study was to detect and characterize extended-spectrum ß-lactamase (ESBL) - and plasmid-mediated AmpC (pAmpC)-producing clinical strains of Escherichia coli at Maputo Central Hospital (MCH), a 1000-bed reference hospital in Maputo, Mozambique. METHODS: A total of 230 clinical isolates of E. coli from urine (n = 199) and blood cultures (n = 31) were collected at MCH during August-November 2015. Antimicrobial susceptibility testing was performed by the disc diffusion method and interpreted according to EUCAST guidelines. Isolates with reduced susceptibility to 3rd generation cephalosporins were examined further; phenotypically for an ESBL-/AmpC-phenotype by combined disc methods and genetically for ESBL- and pAmpC-encoding genes by PCR and partial amplicon sequencing as well as genetic relatedness by ERIC-PCR. RESULTS: A total of 75 isolates with reduced susceptibility to cefotaxime and/or ceftazidime (n = 75) from urine (n = 58/199; 29%) and blood (n = 17/31; 55%) were detected. All 75 isolates were phenotypically ESBL-positive and 25/75 (33%) of those also expressed an AmpC-phenotype. ESBL-PCR and amplicon sequencing revealed a majority of blaCTX-M (n = 58/75; 77%) dominated by blaCTX-M-15. All AmpC-phenotype positive isolates (n = 25/75; 33%) scored positive for one or more pAmpC-genes dominated by blaMOX/FOX. Multidrug resistance (resistance ≥ three antibiotic classes) was observed in all the 75 ESBL-positive isolates dominated by resistance to trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin. ERIC-PCR revealed genetic diversity among strains with minor clusters indicating intra-hospital spread. CONCLUSION: We have observed a high prevalence of MDR pAmpC- and/or ESBL-producing clinical E. coli isolates with FOX/MOX and CTX-Ms as the major ß-lactamase types, respectively. ERIC-PCR analyses revealed genetic diversity and some clusters indicating within-hospital spread. The overall findings strongly support the urgent need for accurate and rapid diagnostic services to guide antibiotic treatment and improved infection control measures.

Low-molecular-weight chitosan relieves enterotoxigenic Escherichia coli-induced growth retardation in weaned pigs.

The objective of the present study was to evaluate the effects of low-molecular-weight chitosan (LMWC) on the growth performance, immune responses and intestinal health of weaned pigs challenged by enterotoxigenic Escherichia coli (ETEC). A total of 32 weaned pigs were randomly allocated to four treatments: non-challenged (fed with basal diet), ETEC-challenged (fed with basal diet) and ETEC-challenged plus 50 or 100 mg/kg LMWC supplementation, respectively. After 11 days feeding, the non-challenged pigs were infused with sterilised Luria-Bertani culture, while the remaining pigs were infused with 2.6 × 1011 colony-forming units of ETEC. At 3 days post-challenge, all pigs were administered d-xylose at 0.1 g/kg body weight. One hour later, blood samples were obtained, and the pigs then euthanised to collect intestinal samples. Data showed that only 100 mg/kg LMWC supplementation attenuated (P < 0.05) the average daily gain reduction caused by ETEC. Furthermore, besides the decreased (P < 0.05) serum tumour necrosis factor-α and immunoglobulin (Ig) G concentrations detected in ETEC-challenged pigs supplemented with LMWC at 50 or 100 mg/kg, the higher dose (100 mg/kg) also decreased (P < 0.05) the serum IgM concentration and increased (P < 0.05) the villus height and villus height-to-crypt depth ratio in both the jejunum and ileum, and the sucrase activity in the ileal mucosa. Moreover, LMWC supplementation (50 or 100 mg/kg) in ETEC-challenged pigs elevated (P < 0.05) the mRNA levels of jejunal mucosal peptide transporter 1 and ileal mucosal peptide transporter 1, divalent metal transporter 1 and zinc transporter 1, and decreased (P < 0.05) the ileal and caecal E. coli abundances, while 100 mg/kg LMWC additionally elevated (P < 0.05) the ileal Bacillus abundance, and caecal and colonic Bifidobacterium abundances. These results suggest that LMWC helps alleviate ETEC-induced growth retardation in weaned pigs, which could be associated with the inhibition of the immune responses and improved intestinal health.

Combined Enteral and Parenteral Glutamine Supplementation in Endotoxemic Swine: Effects on Portal and Systemic Circulation Levels.

OBJECTIVE: To measure plasma glutamine (GLN) levels in systemic and portal circulation after combined enteral and parenteral administration in early endotoxemic swine. We hypothesized that this combination will be more efficient than intravenous administration alone in restoring plasma levels during the course of endotoxemia. MATERIALS AND METHODS: Endotoxemia was induced with Escherichia coli O111:B4 lipopolysaccharide (LPS) (250 µg/kg body weight) in 16 anes-thetized, fasted swine and maintained by constant infusion (2 µg/kg/h) over 180 min. Another 16 swine served as controls. After infusion with LPS or placebo, GLN was administered intravenously, enterally or in combination (0.5 g/kg i.v. plus 0.5 g/kg enterally) over 30 min. At 0, 15, 30, 45, 60, 120 and 180 min, blood was drawn from the systemic and portal circulation for colorimetric assessment of GLN. RESULTS: In healthy, placebo-alone swine, GLN levels remained stable throughout the study. Intravenous and combined infusion increased systemic levels (p = 0.001), but after enteral administration alone, a smaller effect was observed (p = 0.026). Portal levels were increased after combined, enteral and intravenous administration (p = 0.001). In endotoxemia, systemic and portal levels decreased significantly. Intravenous and, to a greater extent, combined administration increased systemic levels (p = 0.001), while enteral administration only had a small effect (p = 0.001). In the portal vein, intravenous and combined treatment increased plasma levels (p = 0.001), whereas enteral supplementation alone had again a small, yet significant effect (p = 0.001). CONCLUSIONS: The findings indicate that combined GLN supplementation is superior to intravenous treatment alone, in terms of enhanced availability in systemic and portal circulations. Thus, combined treatment at the onset of endotoxemia is a beneficial practice, ensuring adequate GLN to compensate for the resulting intracellular shortage.

Impact of host-pathogen-treatment tripartite components on early mortality of patients with Escherichia coli bloodstream infection: Prospective observational study.

BACKGROUND: Risk factors affecting early morality of patients with Escherichia coli bloodstream infection (BSI) were investigated including the host-pathogen-treatment tripartite components. METHODS: Six general hospitals in South Korea participated in this multicentre prospective observational study from May 2016 to April 2017 and a total of 1492 laboratory-confirmed E. coli BSI cases were studied. Cox regression was used to estimate risks of the primary endpoint, i.e., all-cause mortality within 30 days from the initial blood culture. Six multivariate analysis models were constructed in accordance to the clinical importance and intra- and inter-component multicollinearity. FINDINGS: Among the 1492 E. coli BSI cases, 9.5% (n = 141) patients expired within 30 days. Six models of multivariate analysis indicated risk factors of critical illness, primary infection of peritoneum, and chronic liver disease including cirrhosis for host variables; of phylogenetic group B2, ST131-sublineage H30Rx, multidrug resistance, group 1 CTX-M extended-spectrum beta-lactamase production, and having either of fyuA, afa, and sfa/foc virulence genes for causative E. coli pathogen variables; and of delayed definitive therapy for antimicrobial treatment variables. In addition, as a protective factor, primary urinary tract infection was identified. INTERPRETATION: Despite decades' effort searching for the risk factors for E. coli BSI, systemic understanding covering the entire tripartite component is still lacking. This study detailed the organic impact of host-pathogen-treatment tripartite components for early mortality in patients with E. coli BSI.

Bilayer polymeric nanocapsules: A formulation approach for a thermostable and adjuvanted E. coli antigen vaccine.

One of the strategies used to improve the immunogenicity of purified protein antigens has relied on their association with synthetic nanocarriers, which, in general, have functioned as simple antigen containers. Here, we present a more advanced strategy based on the design of an antigen nanocarrier at the molecular level. The nanocarrier is composed of a vitamin E oily core, surrounded by two layers: a first layer of chitosan and a second of dextran sulphate. The selected antigen, IutA protein from Escherichia coli, was harboured between the two polymeric layers. The final bilayer nanocapsules had a nanometric size (≈ 200 nm), a negative zeta potential (< -40 mV) and a good antigen association efficiency (≈ 70%). The bilayer architecture led to an improvement on the formulation stability and the controlled release of the associated antigen. Remarkably, after being administered to mice, bilayer nanocapsules elicited higher IgG levels than those obtained with antigen precipitated with Alum. Moreover, freeze-dried nanocapsules were stable at room temperature for, at least, 3 months. These promising data, in addition to their contribution to the development of an uropathogenic E. coli vaccine, has allowed us to validate these novel bilayer nanocapsules as adequate platforms for the delivery of protein antigens.

Therapeutic effects of 5,2'-dibromo-2,4',5'-trihydroxydiphenylmethanone (LM49) in an experimental rat model of acute pyelonephritis by immunomodulation and anti-inflammation.

Antibiotics are still the primary therapy for acute pyelonephritis (APN); rarely, natural polyphenols are also used. LM49 is a novel marine bromophenol derivative displaying strong anti-inflammatory effects. We investigated the therapeutic efficacy of LM49 in an experimental rat model of APN. The model was established by injecting 0.5 mL Escherichia coli (ATCC 25922, 108 CFU/mL) into the urinary bladders of Sprague Dawley rats. This model showed increased kidney viscera indices and renal bacterial growth scores, as well as pathological changes in kidneys. We also performed a broth microdilution antimicrobial susceptibility test of the E. coli strain. Both norfloxacin and LM49 treatment reduced kidney viscera indices and decreased microbial counts in urine cultures and kidney homogenates in APN rats. However, in vitro experiments showed that LM49 did not directly inhibit bacteria. Rather, LM49 treatment inhibited inflammatory cell infiltration or abscess and improved tissue lesions in the renal medullary junction, renal pelvis, and calyx, and high-dose LM49 treatment inhibited the production of inflammatory interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) in serum. CD4+ T cells were higher in the LM49 groups treated with high, medium, and low doses than in the model group, whereas only high-dose LM49 treatment increased the number of CD8+ T cells, as compared with that in the model group. However, LM49 treatment did not influence hematological parameters. Our results show that LM49 therapeutic effects in an APN animal model may be achieved by regulating immune responses and inhibiting inflammatory mediators, suggesting it as a candidate APN treatment.

Potential of the Cnidium monnieri fruits as an immune enhancer in Escherichia coli infection model.

OBJECTIVES: The Cnidium monnieri fruits (CMF) were studied how they act on immune system as a novel immunostimulator against the infectious disease. METHODS: Macrophages were treated with CMF, and nitric oxide (NO) and tumour necrosis factor-α (TNF-α) were measured, and phagocytosis of macrophages was detected using FITC-labelled Escherichia coli. The protective effect of CMF against E. coli infection in mice was examined. The survival rate was monitored daily for up to 5 days. And then the viable bacteria count of serum and the immunological mediator (NO, TNF-α, interleukin (IL)-12 and IL-6) of serum, splenocyte and peritoneal macrophages were analysed. KEY FINDINGS: The CMF significantly enhanced the concentrations of NO and TNF-α and the phagocytosis activity in macrophages. The oral administration of CMF for five consecutive days before infection prolonged the survival rate. Treatment with CMF significantly stimulated the phagocytosis of peritoneal macrophages and induced the immunological mediator of serum, splenocyte and peritoneal macrophages against the E. coli infection. CONCLUSIONS: The host-protective effects of CMF might be archived by improving immune response, and CMF could act to prevent pathogenic microbial infections with immunomodulation.

The Association between Serum 25-Hydroxy Vitamin D Level and Urine Cathelicidin in Children with a Urinary Tract Infection.

OBJECTIVE: Cathelicidin is an important antimicrobial peptide in the urinary tract. Cathelicidin expression is strongly stimulated by 1,25-dihydroxy vitamin D in epithelial cells, macrophages/monocytes, and neutrophils. Vitamin D and cathelicidin status in children with urinary tract infection (UTI) caused by Escherichia coli is unknown. To establish the relationship between serum vitamin D and urine cathelicidin levels in children with a UTI caused by Escherichia coli. METHODS: Serum 25-hydroxy vitamin D and urine cathelicidin levels were measured in 36 patients with UTI (mean age 6.8±3.6 years, range: 0.25-12.6 years) and 38 controls (mean age 6.3±2.8 years, range: 0.42-13 years). RESULTS: There were no significant differences in urine cathelicidin levels between the study and control groups (p>0.05). Eight (22.2%) patients in the study group and 21 (58.3%) children in the control group were found to have sufficient vitamin D (≥20 ng/mL). Patients with sufficient vitamin D had higher urine cathelicidin levels than the controls with sufficient vitamin D (respectively 262.5±41.1 vs. 168±31.6 ng/mL, p=0.001). There were no significant differences between the patients and controls with insufficient vitamin D (p>0.05). CONCLUSION: The children with vitamin D insufficiency may not be able to increase their urine cathelicidin level during UTI caused by Escherichia coli. There is a need of prospective studies in order to prove a beneficial effect of vitamin D supplementation for the restoration of cathelicidin stimulation and consequently for prevention of UTI recurrence.

Butyrate upregulates endogenous host defense peptides to enhance disease resistance in piglets via histone deacetylase inhibition.

Butyrate has been used to treat different inflammatory disease with positive outcomes, the mechanisms by which butyrate exerts its anti-inflammatory effects remain largely undefined. Here we proposed a new mechanism that butyrate manipulate endogenous host defense peptides (HDPs) which contributes to the elimination of Escherichia coli O157:H7, and thus affects the alleviation of inflammation. An experiment in piglets treated with butyrate (0.2% of diets) 2 days before E. coli O157:H7 challenge was designed to investigate porcine HDP expression, inflammation and E. coli O157:H7 load in feces. The mechanisms underlying butyrate-induced HDP gene expression and the antibacterial activity and bacterial clearance of macrophage 3D4/2 cells in vitro were examined. Butyrate treatment (i) alleviated the clinical symptoms of E. coli O157:H7-induced hemolytic uremic syndrome (HUS) and the severity of intestinal inflammation; (ii) reduced the E. coli O157:H7 load in feces; (iii) significantly upregulated multiple, but not all, HDPs in vitro and in vivo via histone deacetylase (HDAC) inhibition; and (iv) enhanced the antibacterial activity and bacterial clearance of 3D4/2 cells. Our findings indicate that butyrate enhances disease resistance, promotes the clearance of E. coli O157:H7, and alleviates the clinical symptoms of HUS and inflammation, partially, by affecting HDP expression via HDAC inhibition.

[Clinical features and antibiotic resistance of Escherichia coli bloodstream infections in children].

OBJECTIVE: To analyze risk factors, clinical features, outcomes and antibiotic resistance of Escherichia coli(E.coli) causing bloodstream infections in children. METHOD: All inpatients with E. coli positive blood culture in Beijing Children's Hospital from January 2012 to May 2014 were enrolled; 112 cases were included, 66 cases (58.9%) were male, and 46 cases(41.1%) were female. Age range was 2 days to 16 years. Among them, 43 cases (38.4%) were neonates, 19 cases (17.0%) aged from 1 month to 1 year, 14 cases (12.5%) were 1-3 years old, and 36 cases (32.1%) were over three years old. We analyzed the divisions to which the patients were admitted, source of infection, underlying diseases, clinical characteristics, antibiotic resistance, and treatment outcomes, etc. RESULT: Forty-six cases (41.1%) were treated in division of hematology, 42 (37.5%) in neonatology, 9 (8.0%) in internal medicine, 8 (7.1%) in surgery, and 7 (6.3%) in pediatric intensive care unit. Sixty-five cases(58.0%) had underlying diseases. Fever was the most frequently presented symptom, as it was seen in 91 cases (81.3%); 52 cases(46.4%) had respiratory symptoms. Among these, 43 cases had pneumonia, 3 cases had respiratory failure, 3 cases were diagnosed as upper respiratory tract infection, 2 had pulmonary hemorrhage and 1 case had bronchitis. Twenty-six cases (23.2%)were diagnosed as severe sepsis and purulent meningitis separately, 14 cases(12.5%) had urinary tract infection. There were 73 (65.2%) strains inducing extended spectrum ß-lactamases (ESBLs), of which 6 (8.2%) and 10 (13.7%) strains were resistant to amikacin and carbapenems respectively. Resistance rate against other antimicrobial agents varied from 64.6% to 100%. OUTCOMES: 92 (82.1%) cases were cured or had improvement while 20 patients (17.9%) died or could not be cured at the end of treatment. Positive ESBLs (χ(2) = 6.609, P = 0.010), being complicated with severe sepsis (χ(2) = 40.253, P = 0.000) and requiring mechanical ventilation (χ(2) = 34.441, P = 0.000) indicate poor prognosis. CONCLUSION: Patients with underlying diseases and newborns are susceptible to E. coli bloodstream infection. ESBLs infection, severe sepsis and mechanical ventilation indicate poor prognosis in E. coli blood stream infection. Clinicians may use carbapenems as empirical treatment for ESBLs infection. There may be carbapenem-resistant enterobacteriaceae strains infection if patients receiving treatment with carbapenems have no response.

Responses in whole-body amino acid kinetics to an acute, sub-clinical endotoxin challenge in lambs.

Some effects of parasitism, endotoxaemia or sepsis can be mitigated by provision of extra protein. Supplemented protein may encompass a metabolic requirement for specific amino acids (AA). The current study investigates a method to identify and quantify the amounts of AA required during inflammation induced by an endotoxin challenge. One of each pair of six twin sheep was infused in the jugular vein for 20 h with either saline (control) or lipopolysaccharide (LPS, 2 ng/kg body weight per min) from Escherichia coli. Between 12 and 20 h a mixture of stable isotope-labelled AA was infused to measure irreversible loss rates. From 16 to 20 h all sheep were supplemented with a mixture of unlabelled AA infused intravenously. Blood samples were taken before the start of infusions, and then continuously over intervals between 14 and 20 h. At 20 h the sheep were euthanised, and liver and kidney samples were taken for measurement of serine-threonine dehydratase (SDH) activity. LPS infusion decreased plasma concentrations of most AA (P<0·05; P<0·10 for leucine and tryptophan), except for phenylalanine (which increased P=0·022) and tyrosine. On the basis of the incremental response to the supplemental AA, arginine, aspartate, cysteine, glutamate, lysine (tendency only), glycine, methionine, proline, serine and threonine were important in the metabolic response to the endotoxaemia. The AA infusion between 16 and 20 h restored the plasma concentrations in the LPS-treated sheep for the majority of AA, except for glutamine, isoleucine, methionine, serine and valine. LPS treatment increased (P<0·02) SDH activity in both liver and kidney. The approach allows quantification of key AA required during challenge situations.

Effects of Fuzhuan Brick-Tea Water Extract on Mice Infected with E. coli O157:H7.

Fuzhuan brick-tea extract (FBTE) affects the physiology of mice infected with Escherichia coli O157:H7. For 10 consecutive days, 0.05, 0.5, and 1.0 g/mL FBTE was administered intragastrically to three groups of infected Kunming mice, and changes in immunological function, hematology, and histopathology were examined. The results revealed upregulation of platelets, total protein, and albumin along with downregulation of serum triglycerides, aspartate aminotransferase, creatinine, and urea nitrogen in FBTE-treated mice. Histological sections of stomach, kidney, duodenum, ileum, and colon suggested that infected mucous membranes could be rehabilitated by low- and high-dose FBTE and that inflammation was alleviated. Similarly, increased thymic function in mice treated with middle- and high-dose FBTE led to elevated serum hemolysin antibody titer and increased CD4+ and CD8+ T cells, as indicated by CD4+ and CD8+ expression on intestinal mucosa. Monocyte and macrophage function was improved by three FBTE dosages tested. Colonic microbiota analysis by denaturing gradient gel electrophoresis (DGGE) revealed characteristic bands in infected mice treated with middle- and high-dose FBTE and increased species diversity in Lactobacillus, Bacteroides, and Clostridium cluster IV. These results suggest that FBTE may protect kidney and liver of mice infected with E. coli O157:H7, improve immune function, and regulate the colonic microbiota.

Polyphenol extracts from Punica granatum and Terminalia chebula are anti-inflammatory and increase the survival rate of chickens challenged with Escherichia coli.

Avian pathogenic Escherichia coli (APEC) causes inflammation in multiple organs of chickens called avian colibacillosis, and results in serious economic loss to the chicken industry. Polyphenolic compounds possess a wide range of physiological activities that may contribute to their beneficial effects against inflammation-related diseases. In this study, the curative effect and mechanism of action of the polyphenolic extracts from Punica granatum L. and Terminalia chebula Retz. in chickens challenged with APEC were studied. Specific-pathogen-free white Leghorn chickens (males, 21-d old) were challenged with APEC and then given oral administration of extracts of P. granatum and T. chebula. The extracts decreased the morbidity and inflammation induced by APEC. Data from quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay showed that the extracts of P. granatum and T. chebula polyphenols (GCP) reversed the over-expression genes of the Toll-like receptor (TLR) 2, 4, and 5, down-regulated the activation of nuclear factor-kappa B signal transduction pathways, and inhibited the production of pro-inflammatory cytokines. Naturally occurring GCP may be a potential alternative medicine for the prevention or treatment of avian colibacillosis.

ESBL-producing Escherichia coli isolated from bloodstream infections--antimicrobial susceptibility, conjugative transfer of resistance genes and phylogenetic origin.

BACKGROUND: The prevalence of bloodstream infections (BSIs) due to ESBL-producing Escherichia coli (ESBL-EC) strains has increased dramatically over the past years. OBJECTIVES: Characterization of ESBL-EC isolates collected from BSIs with regard to their antimicrobial susceptibility and phylogenetic background. The conjugative transfer of resistance determinants to the E. coli reference strain K12 C600 was also investigated. MATERIAL AND METHODS: A collection of forty-eight ESBL-EC strains recovered from BSIs was subjected to the study. These strains were obtained from the ICU (intensive care unit) of the Medical University Hospital, Wroclaw, Poland, during a four-year period (2009-2012). All the isolates were screened for ESBL production by the double disk synergy test (DDST). Transferability of plasmid-mediated resistance genes was performed by the conjugational broth method. Susceptibility to antibiotics and chemotherapeutics of clinical isolates and transconjugants was determined by the agar dilution method. PCR assay was used to detect the blaCTX-M gene in ESBL-EC tested and transconjugants. Affiliation to phylogenetic groups was done by the triplex PCR method. RESULTS: Conjugational transfer of plasmids responsible for ESBL to a recipient strain was successful for all the ESBL-EC analyzed (donors). The conjugation frequencies ranging from 2.3×10(-7) to 5.2×10(-1) per donor. In vitro susceptibility testing revealed that all the ESBL-EC isolates and their transconjugants were resistant to most of the antimicrobial agents tested with the exception of carbapenems, tigecycline, and ß-lactam-clavulanate combinations. Moreover, all the donor strains and their transconjugants were found to contain the blaCTX-M gene. The majority of the isolates analyzed belonged to phylogroups B2 (62.5%) and D (25%), whereas groups B1 and A were less frequently represented (8.3% and 4.2%, respectively). CONCLUSIONS: The results of the study confirm the need of antibiotic policies and effective infection control measures in hospital settings to minimize BSIs caused by multi-resistant ESBL-producing pathogens.

Weaned pig responses to Escherichia coli K88 oral challenge when receiving a lysozyme supplement.

Lysozyme is a low-molecular-weight protein with antimicrobial properties. An experiment was conducted to investigate the response of piglets receiving a water-soluble lysozyme supplement [Entegard (EG), Neova Technologies Inc., Abbotsford, British Columbia, Canada; 4,000 lysozyme units/mg] after oral challenge with enterotoxigenic Escherichia coli (ETEC). A total of 36 individually housed weanling pigs were randomly allotted to 1 of the 4 treatments, with 9 replicates per treatment. Treatments were a control (CONT, no additive), antibiotic (AB; 2.5 g/kg of feed of antibiotic with chlortetracycline, sulfamethazine, and penicillin), and EG delivered in the drinking water at concentrations of 0.1% (EG1) and 0.2% (EG2). All pigs received a basal diet similar in composition and nutrients, except for pigs receiving the AB diet, which had an added antibiotic. Pigs were acclimated to treatments for a 7-d period to monitor growth performance. On d 8, blood samples were collected from each pig to obtain serum, and each pig was gavaged with 6 mL (2 × 10(9) cfu/mL) of ETEC solution. Pigs were monitored for another 7 d to assess incidences of diarrhea and growth performance, and then all pigs were killed to obtain intestinal tissue and digesta samples. Treatments did not influence growth performance throughout the study. Greater ETEC counts were observed in the ileal mucosal scrapings (P = 0.001) and colonic digesta (P = 0.025) of pigs in the CONT group compared with pigs in the AB and EG1 groups. Pigs receiving AB and EG1 had greater (P < 0.05) small intestinal weights and ileal villus heights than pigs receiving CONT; however, the ileal villus height-to-crypt depth ratio was greater in pigs fed the AB diet (1.69) compared with those fed the CONT diet (1.34), whereas pigs receiving EG1 were intermediate. Pigs in the EG1 group showed greater (P < 0.001) serum tumor necrosis factor α and IL-6 concentrations before ETEC challenge; however, at 7 d postchallenge, pigs receiving EG2 showed the least (P < 0.05) circulating tumor necrosis factor α and IL-6 concentrations. Overall, better intestinal growth and development, as well as decreased ETEC counts on the intestinal mucosa and serum proinflammatory cytokines, suggest that EG can maintain gut health and function in piglets commensurate with antibiotics. However, it is noteworthy that at the largest dose tested, EG seemed to have a dramatic effect on proinflammatory cytokines but had a minimal or no effect on the other response criteria.

Xiang-qi-tang increases avian pathogenic Escherichia coli-induced survival rate and regulates serum levels of tumor necrosis factor alpha, interleukin-1 and soluble endothelial protein C receptor in chicken.

Xiang-qi-tang (XQT) is a Chinese herbal formula containing rhizoma Cyperi, Andrographis paniculata and Astragalus membranaceus. The present study investigated the effects of XQT on the mortality and inflammatory mediators in a chicken model challenged with avian pathogenic Escherichia coli (APEC). To detect the effect of XQT, the chickens were pretreated with the formula 12 h before being challenged with 10(8) colony forming unit (CFU) of APEC. The results showed that 0.6 g/kg XQT significantly elevated the survival rate of infected chickens. To further investigate the mechanism of decreasing mortality of XQT, we examined plasma inflammatory mediator levels. The levels of tumor necrosis factor alpha (TNF-α), interleukin-1 (IL-1) and soluble endothelial protein C receptor (sEPCR) were significantly increased in chickens challenged with APEC alone, whereas chickens pretreated with 0.6 g/kg XQT showed marked decrease of these inflammatory mediator levels during the death peak. Taken together, this study demonstrates that XQT has protective effects in APEC-treated chickens. The action mechanisms of XQT involve anti-inflammation and antithrombotic activity. These findings may contribute to future research on the action mechanisms of this formula, as well as prevention of or therapy for avian colibacillosis.

Escherichia coli and Staphylococcus aureus: bad news and good news from the European Antimicrobial Resistance Surveillance Network (EARS-Net, formerly EARSS), 2002 to 2009.

Based on data collected by the European Antimicrobial Resistance Surveillance Network (EARS-Net) and the former EARSS, the present study describes the trends in antimicrobial susceptibility patterns and occurrence of invasive infections caused by Escherichia coli and Staphylococcus aureus in the period from 2002 to 2009. Antimicrobial susceptibility results from 198 laboratories in 22 European countries reporting continuously on these two microorganisms during the entire study period were included in the analysis. The number of bloodstream infections caused by E. coli increased remarkably by 71% during the study period, while bloodstream infections caused by S. aureus increased by 34%. At the same time, an alarming increase of antimicrobial resistance in E. coli was observed, whereas for S. aureus the proportion of meticillin resistant isolates decreased. The observed trend suggests an increasing burden of disease caused by E. coli. The reduction in the proportion of meticillin-resistant S. aureus and the lesser increase in S. aureus infections, compared with E. coli, may reflect the success of infection control measures at hospital level in several European countries.

Clinical effects of 2 days of treatment by fosfomycin calcium for acute uncomplicated cystitis in women.

Fosfomycin calcium is a fosfomycin antimicrobial agent with a characteristic structure. After oral administration, the drug is absorbed and excreted via the kidneys in the unchanged form, without being metabolized in the body. It is, therefore, indicated for the treatment of urinary tract diseases, including cystitis and pyelonephritis. In the present study, the clinical usefulness of fosfomycin calcium (FOSMICIN® TABLETS 500) administered orally at the dosage of 1 g (two tablets) three times daily for 2 days was examined in female patients, who were at least 20 years of age, with acute uncomplicated cystitis of bacterial origin. Of the 48 patients enrolled between February 2008 and August 2008, 39 were evaluable for efficacy and safety. Overall evaluation of the cure revealed that microbiological eradication rate (microbiological outcome) and clinical efficacy rate (clinical outcome) at 5-9 days after drug administration (visit 2) were 94.9%. Determination of the microbiological and clinical outcomes for the evaluation of recurrence at 4-6 weeks after drug administration (visit 3) were 75.8 and 85.7%, respectively. Of the 48 patients, 40 (83.3%) returned to the clinic at visit 3. The causative bacterial species for cystitis was Escherichia coli in 31 (79.5%) of the 39 patients evaluable for efficacy and safety. Adverse drug reactions observed during the administration and follow-up periods included mild diarrhea and loose stools in 1 patient each, neither requiring any specific treatment. Evaluation of cure at visit 2 in patients in whom the causative bacterial species for the infection was E. coli revealed a microbiological outcome of 93.5%, and clinical outcome was 96.8%. Furthermore, evaluation for recurrence at visit 3 revealed a microbiological outcome of 74.1% and clinical outcome of 82.1%. When the patients were divided by age into an under 60 years of age group and an over 60 years of age group, the microbiological and clinical outcomes determined for evaluation of cure at visit 2 were 96.4 and 92.9%, respectively, and the corresponding rates determined for the evaluation of recurrence at visit 3 were 87.0 and 96.0%, respectively, in the under 60 years of age group. In the over 60 years of age group, the corresponding microbiological outcome and clinical outcome rates evaluated for cure were 90.9 and 100%, respectively, and those evaluated for recurrence were 50.0 and 60.0%, respectively. These results indicate the usefulness of fosfomycin calcium administered at 1 g three times daily for 2 days for acute uncomplicated cystitis.

Bloodstream infections due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: risk factors for mortality and treatment outcome, with special emphasis on antimicrobial therapy.

This study was conducted to evaluate risk factors for mortality and treatment outcome of bloodstream infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae (ESBL-EK). ESBL production in stored K. pneumoniae and E. coli blood isolates from Jan 1998 to Dec 2002 was phenotypically determined according to NCCLS guidelines and/or the double-disk synergy test. A total of 133 patients with ESBL-EK bacteremia, including 66 patients with ESBL-producing K. pneumoniae and 67 with ESBL-producing E. coli, were enrolled. The overall 30-day mortality rate was 25.6% (34 of 133). Independent risk factors for mortality were severe sepsis, peritonitis, neutropenia, increasing Acute Physiology and Chronic Health Evaluation II score, and administration of broad-spectrum cephalosporin as definitive antimicrobial therapy (P < 0.05 for each of these risk factors). In 117 of the 133 patients, excluding 16 patients who died within 3 days after blood culture sample acquisition, the 30-day mortality rates according to definitive antibiotics were as follows: carbapenem, 12.9% (8 of 62); ciprofloxacin, 10.3% (3 of 29); and others, such as cephalosporin or an aminoglycoside, 26.9% (7 of 26). When patients who received appropriate definitive antibiotics, such as carbapenem or ciprofloxacin, were evaluated, mortality in patients receiving inappropriate empirical antimicrobial therapy was found not to be significantly higher than mortality in those receiving appropriate empirical antimicrobial therapy (18.9 versus 15.5%; P = 0.666). Carbapenem and ciprofloxacin were the most effective antibiotics in antimicrobial therapy for ESBL-EK bacteremia. A delay in appropriate definitive antimicrobial therapy was not associated with higher mortality if antimicrobial therapy was adjusted appropriately according to the susceptibility results. Our data suggest that more prudent use of carbapenem as empirical antibiotic may be reasonable.

Effect of anti-CD14 monoclonal antibody on clearance of Escherichia coli bacteremia and endotoxemia.

OBJECTIVE: To determine the effects of an anti-CD14 monoclonal antibody on the clearance of a bacteremic Escherichia coli challenge in the presence or absence of antimicrobial agents. DESIGN: Prospective randomized animal study. SETTING: University-affiliated research laboratory. SUBJECTS: New Zealand White rabbits weighing 1.5-2.5 kg. INTERVENTIONS: Animals were pretreated with either an anti-lapine CD14 monoclonal antibody (immunoglobulin G2a, 5 mg/kg intravenously) or an isotype control monoclonal antibody. The animals then were challenged with 1 x 10(6) E. coli 018:K1 in the presence or absence of ceftazidime (50 mg/kg intravenously). There were four groups of six animals randomized to receive either anti-CD14 monoclonal antibody without ceftazidime, isotype control monoclonal antibody without ceftazidime, anti-CD14 monoclonal antibody with ceftazidime, or isotype control antibody with ceftazidime. MEASUREMENTS AND MAIN RESULTS: Serial measurement of quantitative bacteremia and endotoxemia was performed over 24 hrs after the administration of the bacterial challenge. Animals also underwent necropsy with quantitative bacterial cultures from multiple organ tissue samples. The anti-lapine CD14 monoclonal antibody significantly impaired the bloodstream clearance of E. coli (p <.01) and increased quantitative counts of E. coli in tissue culture samples when compared with isotype control antibody in the absence of simultaneous administration of ceftazidime. No differences in quantitative bacteremia, endotoxemia, or organ tissue counts were found after anti-CD14 antibody and control antibody-treated animals in the presence of ceftazidime treatment. CONCLUSIONS: Anti-CD14 monoclonal antibody has the capacity to interfere with the innate immune response and systemic microbial clearance in experimental animals with E. coli bacteremia. The concomitant administration of effective antimicrobial therapy eliminated differences in the rate of microbial clearance between the control antibody and the CD14 monoclonal antibody. These results indicate that care should be taken in clinical trials with anti-CD14 monoclonal antibodies to ensure that adequate antimicrobial therapy is administered in the presence of systemic bacterial infection.