Chemical composition, antibacterial activity and related mechanism of valonia and shell from Quercus variabilis Blume (Fagaceae) against Salmonella paratyphi a and Staphylococcus aureus.

BACKGROUND: Plant secondary metabolites and phytochemicals that exhibit strong bioactivities have potential to be developed as safe and efficient natural antimicrobials against food contamination and addressing antimicrobial resistance caused by the overuse of chemical synthetic preservative. In this study, the chemical composition, antibacterial activities and related mechanism of the extracts of the valonia and the shell of Quercus variabilis Blume were studied to determine its potential as a safe and efficient natural antimicrobial. METHODS: The phenolic compositions of valonia and shell extracts were determined by folin-ciocalteau colourimetric method, sodium borohydride/chloranil-based assay and the aluminium chloride method and then further identified by the reverse-phase HPLC analysis. The antibacterial activities of valonia and shell extracts were evaluated by the agar disk diffusion method and agar dilution method. The related antibacterial mechanism was explored successively by the membrane of pathogens effect, phosphorous metabolism, whole-cell proteins and the microbial morphology under scanning electron microscopy. RESULTS: The n-butanol fraction and water fraction of valonia along with n-butanol fraction of the shell contains enrich phenolics including ellagic acid, theophylline, caffeic acid and tannin acid. The n-butanol fraction and ethanol crude extracts of valonia exhibited strong antibacterial activities against Salmonella paratyphi A (S. paratyphi A) and Staphylococcus aureus (S. aureus) with the DIZ values ranged from 10.89 ± 0.12 to 15.92 ± 0.44, which were greater than that of the Punica granatum (DIZ: 10.22 ± 0.18 and 10.30 ± 0.21). The MIC values of the n-butanol fraction and ethanol crude extracts of valonia against S. paratyphi A and S. aureus were 1.25 mg/ml and 0.625 mg/ml. The related antibacterial mechanism of n-butanol fraction and ethanol crude extracts of valonia may be attributed to their strong impact on membrane permeability and cellular metabolism. Those extracts exhibited strong antibacterial activity according to inhibit the synthesis of bacterial proteins and seriously change morphological structure of bacterial cells. CONCLUSIONS: The n-butanol fraction and ethanol crude extracts of valonia had reasonably good antibacterial activities against S. paratyphi A and S. aureus. This study suggests possible application of valonia and shell as natural antimicrobials or preservatives for food and medical application.

Current antibiotic use in the treatment of enteric fever in children.

Background & objectives: Antimicrobial resistance is a major challenge in the treatment of typhoid fever with limited choices left to empirically treat these patients. The present study was undertaken to determine the current practices of antibiotic use in children attending a tertiary care hospital in north India. Methods: This was a descriptive observational study in children suffering from enteric fever as per the case definition including clinical and laboratory parameters. The antibiotic audit in hospitalized children was measured as days of therapy per 1000 patient days and in outpatient department (OPD) as antibiotic prescription on the treatment card. Results: A total of 128 children with enteric fever were included in the study, of whom, 30 were hospitalized and 98 were treated from OPD. The mean duration of fever was 9.5 days at the time of presentation. Of these, 45 per cent were culture positive with Salmonella Typhi being aetiological agent in 68 per cent followed by S. Paratyphi A in 32 per cent. During hospitalization, the average length of stay was 10 days with mean duration of defervescence 6.4 days. Based on antimicrobial susceptibility ceftriaxone was given to 28 patients with mean duration of treatment being six days. An additional antibiotic was needed in six patients due to clinical non-response. In OPD, 79 patients were prescribed cefixime and additional antibiotic was needed in five during follow up visit. Interpretation & conclusions: Based on our findings, ceftriaxone and cefixime seemed to be the first line of antibiotic treatment for typhoid fever. Despite susceptibility, clinical non-response was seen in around 10 per cent of the patients who needed combinations of antibiotics.

Identifying the mechanism underlying treatment failure for Salmonella Paratyphi A infection using next-generation sequencing - a case report.

BACKGROUND: Salmonella is a notorious pathogen that causes gastroenteritis in humans and the emergence of resistance to third-generation cephalosporins and azithromycin have raised concern. There has been rare case of Salmonella Paratyphi A infection accompanied by spondylitis. Here, we report a case of initial antibiotic treatment failure in a Korean man with Salmonella Paratyphi A infection and conducted next-generation sequencing (NGS) to determine the cause of failure of initial treatment for Salmonella Paratyphi A infection. CASE PRESENTATION: A 70-year-old man was admitted to Chosun University Hospital with reported consistent low back pain with a history of having 5 days of chills and fever in another hospital a month ago. He was administered ceftriaxone (2 g daily) for 18 days including initial treatment to cover Salmonella enterica. The antimicrobial susceptibility test using MIC plate, found that the identified organism was resistant to ciprofloxacin and nalidixic acid. Moreover, the Salmonella Paratyphi A isolates were found to have an MIC > 16 mg/L for azithromycin, as he had resistance to both azithromycin and nalidixic acid, the treatment was switched to a combination of ciprofloxacin and cefotaxime. We carried out next-generation sequencing (NGS) to determine the cause of failure of initial treatment for Salmonella Paratyphi A infection. NGS showed that the amino acid substitution GyrA S83F and the expression of multiple RNA-family efflux pumps led to a high-level resistance to quinolone. No genes related to ceftriaxone resistance, such as CTX-M, CMY-2, or other extended-spectrum beta-lactamases were identified in Salmonella enterica Paratyphi A using NGS. The GyrA S83F mutation and the expression of multiple RNA-family efflux pumps may have contributed to the treatment failure of ceftriaxone, even though the MIC of the isolate to ceftriaxone was less than 1. CONCLUSION: This case involved a Salmonella Paratyphi A infection accompanied by spondylitis. To our knowledge, this is the first report to elucidate the mechanism underlying antimicrobial resistance using NGS.

Enteric Fever in Cambodia: Community Perceptions and Practices Concerning Disease Transmission and Treatment.

Enteric fever is a systemic bacterial infection in humans that is endemic in Cambodia and for which antibiotic resistance is increasingly reported. To guide public health programs, this qualitative study sought to explore community perceptions on transmission and treatment. Participant observation was carried out in hospital settings, pharmacies, and at a community level in Phnom Penh. In-depth interviews 39 and one focus group discussion were carried out with blood culture-confirmed enteric fever patients and purposively selected key informants. Informants were theoretically sampled based on initial themes identified using abductive analysis. Nvivo 11 was used for thematic coding. An urgent need to address health literacy concerning the transmission of enteric fever was identified, as lay informants did not link the disease and its symptoms to bacterial contamination of foods and drinks but rather to foods considered "bad" following humoral illness interpretations. As a result, lay informants considered recurrence of enteric fever preventable with appropriate dietary restrictions and Khmer traditional medicines. This study also reveals pluralistic health-care-seeking behavior. For initial and mild symptoms, patients preferred home treatment or traditional healing practices; limited household finances delayed treatment seeking. When symptoms persisted, patients first visited drug outlets or private practitioners, where they received a mix of nonessential medicines and one or more antibiotics often without prescription or confirmation of diagnosis. Inappropriate use of antibiotics was common and was related to diagnostic uncertainty and limited finances, factors which should be addressed during future efforts to improve the uptake of appropriate diagnostics and treatment of enteric fever.

Eco-friendly preparation of zinc oxide nanoparticles using Tabernaemontana divaricata and its photocatalytic and antimicrobial activity.

The present work reports the green synthesis of Zinc Oxide Nanoparticles (ZnO NPs) using aqueous Tabernaemontana divaricata green leaf extract. ZnO NPs have been characterized by X-ray diffraction (XRD), Ultra Violet-Visible (UV-Vis) studies, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infra Red (FT-IR) analysis. XRD pattern analysis confirms the presence of pure hexagonal wurtzite crystalline structure of ZnO. The TEM images reveal the formation of spherical shape ZnO NPs with the sizes ranging from 20 to 50 nm. The FT-IR analysis suggests that the obtained ZnO NPs have been stabilized through the interactions of steroids, terpenoids, flavonoids, phenyl propanoids, phenolic acids and enzymes present in the leaf extract. Mechanism for the formation of ZnO NPs using Tabernaemontana divaricata as bioactive compound is proposed. As prepared ZnO NPs reveals antibacterial activity against three bacterial strains, Salmonella paratyphi, Escherichia coli and Staphylococcus aureus. The ZnO NPs shows higher antibacterial activity against S. aureus and E. coli and lesser antibacterial activity against S. paratyphi compared to the standard pharmaceutical formulation. Photocatalytic activity of synthesized ZnO NPs was analyzed for methylene blue (MB) dye degradation with sunlight. Almost complete degradation of dye occurred in 90 min. This nano-ZnO, prepared by eco-friendly method will be much useful for dye removal and bacterial decontamination.

Treatment Response in Enteric Fever in an Era of Increasing Antimicrobial Resistance: An Individual Patient Data Analysis of 2092 Participants Enrolled into 4 Randomized, Controlled Trials in Nepal.

BACKGROUND.: Enteric fever, caused by Salmonella Typhi and Salmonella Paratyphi A, is the leading cause of bacterial febrile disease in South Asia. METHODS.: Individual data from 2092 patients with enteric fever randomized into 4 trials in Kathmandu, Nepal, were pooled. All trials compared gatifloxacin with 1 of the following comparator drugs: cefixime, chloramphenicol, ofloxacin, or ceftriaxone. Treatment outcomes were evaluated according to antimicrobial if S. Typhi/Paratyphi were isolated from blood. We additionally investigated the impact of changing bacterial antimicrobial susceptibility on outcome. RESULTS.: Overall, 855 (41%) patients had either S. Typhi (n = 581, 28%) or S. Paratyphi A (n = 274, 13%) cultured from blood. There were 139 (6.6%) treatment failures with 1 death. Except for the last trial with ceftriaxone, the fluoroquinolone gatifloxacin was associated with equivalent or better fever clearance times and lower treatment failure rates in comparison to all other antimicrobials. However, we additionally found that the minimum inhibitory concentrations (MICs) against fluoroquinolones have risen significantly since 2005 and were associated with increasing fever clearance times. Notably, all organisms were susceptible to ceftriaxone throughout the study period (2005-2014), and the MICs against azithromycin declined, confirming the utility of these alternative drugs for enteric fever treatment. CONCLUSION.: The World Health Organization and local government health ministries in South Asia still recommend fluoroquinolones for enteric fever. This policy should change based on the evidence provided here. Rapid diagnostics are urgently required given the large numbers of suspected enteric fever patients with a negative culture.

Absence of multidrug resistance in Salmonella enterica serotypes Typhi and Paratyphi A isolates with intermediate susceptibility to ciprofloxacin.

BACKGROUND: We describe the antimicrobial susceptibility pattern of 64 blood stream isolates of Salmonella enterica serotypes Typhi and Paratyphi A studied from January 2013 to December 2014 at a tertiary care centre in North India. METHODS: Isolates were identified by standard biochemical reactions and confirmed by slide agglutination using specific antisera. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion method and by E-test. RESULTS: In this study, 92% (46/50) of Salmonella Typhi and all Paratyphi A (n=14) isolates were susceptible to ampicillin, chloramphenicol and cotrimoxazole. Eighty percent of Typhi (40/50) and 64% (9/14) of Paratyphi A were intermediately susceptible to ciprofloxacin. Nineteen percent (12/64) of isolates were resistant to ciprofloxacin. No resistance to ceftriaxone and azithromycin was detected. CONCLUSIONS: Our study adds to the current knowledge of world-wide reports of multidrug resistance in S. Typhi.

Antimicrobial resistance in Salmonella enterica serovar typhi and paratyphi in South Asia-current status, issues and prospects.

The human race owes a debt of gratitude to antimicrobial agents, penicillin and its successors that have saved people from tremendous pain and suffering in the last several decades. Unfortunately, this consideration is no more true, as millions of people are prone to the challenging threat of emergence of antimicrobial resistance worldwide and the menace is more distressing in developing countries. Comparable with other bacterial species, Salmonella enterica serovar Typhi (S. typhi) and Paratyphi (S. paratyphi) have been evolving multidrug resistance (MDR) against a wide array of antibiotics, including chloramphenicol, ampicillin and co-trimoxazole, and globally affecting 21 million people with 220,000 deaths each year. S. typhi and S. paratyphi infections are also endemic in South Asia and a series of antibiotics used to treat these infections, have been losing efficacy against enteric fever. Currently, quinolones are regarded as a choice to treat MDR Salmonella in these regions. Travel-related cases of enteric fever, especially from South Asian countries are the harbinger of the magnitude of MDR Salmonella in that region. Conclusively, the MDR will continue to grow and the available antimicrobial agents would become obsolete. Therefore, a radical and aggressive approach in terms of rational use of antibiotics during treating infections is essentially needed.

Decreased ciprofloxacin susceptibility in Salmonella Typhi and Paratyphi infections in ill-returned travellers: the impact on clinical outcome and future treatment options.

The emergence of decreased ciprofloxacin susceptibility (DCS) in Salmonella enterica serovar Typhi and serovar Paratyphi A, B or C limits treatment options. We studied the impact of DCS isolates on the fate of travellers returning with enteric fever and possible alternative treatment options. We evaluated the clinical features, susceptibility data and efficacy of empirical treatment in patients with positive blood cultures of a DCS isolate compared to patients infected with a ciprofloxacin-susceptible (CS) isolate in the period from January 2002 to August 2008. In addition, the pharmacokinetic and pharmacodynamic parameters of ciprofloxacin, levofloxacin and gatifloxacin were determined to assess if increasing the dose would result in adequate unbound fraction of the drug 24-h area under the concentration-time curve/minimum inhibitory concentration (ƒAUC(0-24)/MIC) ratio. Patients with DCS more often returned from the Indian subcontinent and had a longer fever clearance time and length of hospital stay compared to patients in whom the initial empirical therapy was adequate. The mean ƒAUC(0-24)/MIC was 41.3 ± 18.8 in the patients with DCS and 585.4 ± 219 in patients with a CS isolate. For DCS isolates, the mean ƒAUC0-24/MIC for levofloxacin was 60.5 ± 28.7 and for gatifloxacin, it was 97.9 ± 28.0. Increasing the dose to an adequate ƒAUC(0-24)/MIC ratio will lead to conceivably toxic drug levels in 50% of the patients treated with ciprofloxacin. Emerging DCS isolates has led to the failure of empirical treatment in ill-returned travellers. We demonstrated that, in some cases, an adequate ƒAUC(0-24)/MIC ratio could be achieved by increasing the dose of ciprofloxacin or by the use of alternative fluoroquinolones.

Enteric fever in Karachi: current antibiotic susceptibility of Salmonellae isolates.

OBJECTIVE: To determine the current sensitivity and resistance profile of Salmonellae (S.) isolates in a laboratory setting. STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: Dr. Essa`s Laboratory and Diagnostic Centre, Karachi, Pakistan, from November 2008 - October 2010. METHODOLOGY: Isolates from blood culture specimens of 481 bacteraemic patients were identified using conventional biochemical tests. Salmonellae was confirmed with specific antisera and their antibiograms determined by Kirby-Bauer Disc Diffusion method using 12 relevant antibiotics. Inclusions of the study were bacteraemia documented in all blood samples positive for S. typhi, S. paratyphi-A and B. Exclusions were all samples other than blood and blood samples negative for S. typhi and S. paratyphi-A and B during the same period. Multidrug resistance (MDR) of isolates was defined as the isolates showing resistance to all conventional anti-typhoid medicines i.e., Chloramphenicol, Ampicillin and Co-trimoxazole. RESULTS: Specimens (n=217) yielded 131 Salmonellae typhi (60.36%), 71 S. paratyphi-A (32.71%), and 15 S. paratyphi-B (6.9%); these were sensitive to the Quinolones [Enoxacin: 94.96% (n=91), Ciprofloxacin, 96.47% (n=182), Ofloxacin: 95.74% (n=203)], and Cephalosporins [Cefixime: 96.62% (n=202), Cefotaxime: 99.17% (n=206), Ceftriaxone: 98.79% (n=208)]. Resistance to Amoxicillin was 96.48% (n=128) and 29.91% (n=78) to Co-trimoxazole. About 62.64% (n=136) of the isolates were MDR strains. CONCLUSION: Ciprofloxacin is currently a suitable empirical choice in presumed enteric fever cases, but culture and sensitivity analysis should be encouraged and results incorporated in prescription strategy. Increasing frequency of S. paratyphi-A isolates possibly suggests incomplete coverage employing monovalent vaccine.

In vitro susceptibility of typhoidal Salmonellae against newer antimicrobial agents: a search for alternate treatment options.

OBJECTIVES: To determine the minimum inhibitory concentrations (MICs) of ceftriaxone, azithromycin, pefloxacin, cefipime and imipenem for Salmonella Typhi (S. Typhi) and Paratyphi. METHODS: One hundred and fifty four isolates of Salmonella Typhi and S. Paratyphi A, B and C growing in blood culture were selected. MICs of ceftriaxone, azithromycin, pefloxacin, cefipime and imipenem were performed by agar dilution method as recommended by clinical laboratory standard institutes. RESULTS: MIC90 of azithromycin and pefloxacin was 8 microg/ml, cefipime was 0.06 microg/ml and imipenem was 0.5 microg/ml. None of the strains were found to be resistant to ceftriaxone but 3 isolates showed higher MIC value of 2 microg/ml. CONCLUSION: Azithromycin appears a suitable alternate for the treatment of typhoid in the community. Imipenem and cefipime are good options in complicated cases to be treated in hospital settings. Pefloxacin cannot be used as MICs are higher. Presence of isolates with higher MIC of ceftriaxone is serious and stresses upon continuous laboratory surveillance to guide clinicians appropriately.

Prevalence of Salmonella typhi and paratyphi infection in children: a hospital based study.

The purpose of this study was to find out the prevalence and antibiotic sensitivity pattern of Salmonella typhi and paratyphi isolated from children presenting with fever at Kanti Children's Hospital in Kathmandu, Nepal. A total of 9,856 blood samples collected for culture during one year period (April 2007 to March 2008) were included in the study. Out of total, 235 (2.0%) were positive for S. typhi and paratyphi A. Of the total positive, 195 (83.0%) were S. typhi and 40 (17.0%) were S. paratyphi A. The growth positive rate in two genders (M: 53.2% and F: 46.8%) was not significant (P > 0.05). Over two-third of cases were clustered in the age-group of 1-10 years. The occurrence of infections was common in summer months (rainy season). S. typhi was found to be most sensitive to cefotaxime (100.0%) followed by ceftriaxone (98.9%), ofloxacin (93.5%), cotrimoxazole (93.5%) and chloramphenicol (93.2%) and was least sensitive to amoxyccilin (66.7%) followed by ciprofloxacin (86.6%). S. paratyphi also was found to be most sensitive to cefotaxime (100.0%), followed by ceftriaxone (97.4%), cotrimoxazole (97.1%) and chloramphenicol (92.5%) and was least sensitive to amoxycillin (15.0%) followed by ciprofloxacin (51.3%) and ofloxacin (70.3%).

Antibacterial activities of Emblica officinalis and Coriandrum sativum against Gram negative urinary pathogens.

Present investigation is focused on antibacterial potential of aqueous infusions and aqueous decoctions of Emblica officinalis (amla) and Coriandrum sativum (coriander) against 345 bacterial isolates belonging to 6 different genera of Gram negative bacterial population isolated from urine specimens by employing well diffusion technique. Aqueous infusion and decoction of Emblica officinalis exhibited potent antibacterial activity against Escherichia coli (270), Klebsiella pneumoniae (51), K. ozaenae (3), Proteus mirabilis (5), Pseudomonas aeruginosa (10), Salmonella typhi (1), S. paratyphi A (2), S. paratyphi B (1) and Serratia marcescens (2) but did not show any antibacterial activity against Gram negative urinary pathogens.

Ciprofloxacin treatment failure in a case of typhoid fever caused by Salmonella enterica serotype Paratyphi A with reduced susceptibility to ciprofloxacin.

This report describes a case of ciprofloxacin treatment failure in a patient with enteric fever caused by Salmonella enterica serotype Paratyphi A. The organism was isolated from a blood culture from a patient who was treated with oral ciprofloxacin (500 mg every 12 h) for 13 days. The organism showed reduced susceptibility to ciprofloxacin (MIC 0.75 microg ml-1) and was resistant to nalidixic acid. The patient was then placed on intravenous ceftriaxone (1 g every 12 h) and responded within 3 days. The patient was discharged after 9 days on ceftriaxone with no relapse on follow-up. This case adds to the increasing incidence of treatment failures with ciprofloxacin in typhoid fever caused by typhoid salmonellae with reduced susceptibility to ciprofloxacin. It also highlights the inadequacy of current laboratory methods for fluoroquinolone susceptibility testing in adequately predicting in vivo activity of ciprofloxacin against typhoid salmonellae and supports calls for new guidelines for fluoroquinolone susceptibility testing of these organisms.

Treatment of enteric fever in children on the basis of current trends of antimicrobial susceptibility of Salmonella enterica serovar typhi and paratyphi A.

PURPOSE: Recent reports indicate decreased susceptibility of S. typhi to fluoroquinolones, especially ciprofloxacin. Chloramphenicol has been suggested as first line therapy of enteric fever in many studies. This is a prospective study that describes the trends of antimicrobial susceptibility of S. typhi and S. paratyphi A causing bacteraemia in children and reports therapeutic failure to ciprofloxacin and evaluates the possible use of chloramphenicol, ampicillin, ciprofloxacin and third generation cephalosporins as first line therapy in the treatment of enteric fever in children. METHODS: The present study was conducted from April 2004 to March 2005 in a superspeciality children hospital at New Delhi. A total of 56 S. typhi and five S. paratyphi A isolates were obtained among the 673 blood cultures performed. Antimicrobial testing was done using disk diffusion technique (NCCLS method) for 13 antimicrobials and MICs were calculated for ampicillin, ciprofloxacin, chloramphenicol and cefotaxime. Analysis of data was done using WHONET software. RESULTS: All 56 isolates of S. typhi were sensitive to amoxycillin+clavulanate, gentamicin, cefixime, cefotaxime and ceftazidime. Multidrug resistance (MDR, resistance to three drugs) was seen in 22 cases (39%) and resistance to five drugs was seen in 12 cases (21%). Only two isolates were resistant to chloramphenicol (3%). MIC 90 for ampicillin, chloramphenicol, ciprofloxacin and cefotaxime were 1.0 microg/ml, 4.0 microg/ml, 64 microg/ml and 0.125 microg/ml respectively. All S. paratyphi A isolates were sensitive to ampicillin and chloramphenicol and resistant to nalidixic acid. MIC distribution data for chloramphenicol revealed elevated MIC but still in susceptible range. CONCLUSIONS: There is an urgent need for further clinical studies to evaluate response to chloramphenicol in such cases. Antimicrobial susceptibility data and MIC distribution favour use of ampicillin as a drug of choice for the treatment of enteric fever. Third generation cephalosporins are also useful but their use should be restricted for complicated cases.

Suboptimal clinical response to ciprofloxacin in patients with enteric fever due to Salmonella spp. with reduced fluoroquinolone susceptibility: a case series.

BACKGROUND: Salmonella spp. with reduced susceptibility to fluoroquinolones have higher than usual MICs to these agents but are still considered "susceptible" by NCCLS criteria. Delayed treatment response to fluoroquinolones has been noted, especially in cases of enteric fever due to such strains. We reviewed the ciprofloxacin susceptibility and clinical outcome of our recent enteric fever cases. METHODS: Salmonella enterica Serotype Typhi (S. Typhi) and Serotype Paratyphi (S. Paratyphi) blood culture isolates (1998-2002) were tested against nalidixic acid by disk diffusion (DD) and agar dilution (AD) and to ciprofloxacin by AD using NCCLS methods and interpretive criteria. Reduced fluoroquinolone susceptibility was defined as a ciprofloxacin MIC of 0.125-1.0 mg/L. The clinical records of patients treated with ciprofloxacin for isolates with reduced fluoroquinolone susceptibility were reviewed. RESULTS: Seven of 21 (33%) S. Typhi and S. Paratyphi isolates had reduced susceptibility to fluoroquinolones (MIC range 0.125-0.5 mg/L). All 7 were nalidixic acid resistant by DD (no zone) and by AD (MIC 128- >512 mg/L). The other 14 isolates were nalidixic acid susceptible and fully susceptible to ciprofloxacin (MIC range 0.015-0.03 mg/L). Five of the 7 cases were treated initially with oral ciprofloxacin. One patient remained febrile on IV ciprofloxacin until cefotaxime was added, with fever recurrence when cefotaxime was discontinued. Two continued on oral or IV ciprofloxacin alone but had prolonged fevers of 9-10 days duration, one was switched to IV beta-lactam therapy after remaining febrile for 3 days on oral/IV ciprofloxacin and one was treated successfully with oral ciprofloxacin. Four of the 5 required hospitalization. CONCLUSIONS: Our cases provide further evidence that reduced fluoroquinolone susceptibility of S. Typhi and S. Paratyphi is clinically significant. Laboratories should test extra-intestinal Salmonella spp. for reduced fluoroquinolone susceptibility.

Expression of full-length bioactive antimicrobial human lactoferrin in potato plants.

A cDNA fragment encoding human lactoferrin (hLF) linked to a plant microsomal retention signal peptide (SEK-DEL) was stably integrated into the Solanum tuberosum genome by Agrobacterium tumefaciens-mediated leaf disk transformation methods. The lactoferrin gene was expressed under control of both the auxin-inducible manopine synthase (mas) P2 promoter and the cauliflower mosaic virus (CaMV) 35S tandem promoter. The presence of the hLF cDNA in the genome of regenerated transformed potato plants was detected by polymerase chain reaction amplification methods. Full-length hLF protein was identified by immunoblot analysis in tuber tissue extracts from the transformed plants by immunoblot analysis. The hLF produced in transgenic plant tissues migrated during polyacrylamide gel electrophoresis as a single band with an approximate molecular mass equal to hLF. Auxin activation of the mas P2 promoter increased lactoferrin expression levels in transformed tuber and leaf tissues to approximately 0.1% of total soluble plant protein. Antimicrobial activity against four different human pathogenic bacterial strains was detected in extracts of lactoferrin-containing potato tuber tissues. This is the first report of synthesis of full length, biologically active hLF in edible plants.

Treatment with ciprofloxacin in children with typhoid fever.

We investigated the use, treatment results and safety of ciprofloxacin in the treatment of childhood typhoid and paratyphoid infections in an industrialized country. The study was retrospective, and the material consisted of children admitted to Hvidovre or Glostrup University Hospitals from 1991 to 1995, and treated with ciprofloxacin for a culture proven diagnosis of typhoid fever. 21 children were included, 18 had positive cultures for Salmonella typhi and 3 had positive cultures for S. paratyphi A. All isolates were fully susceptible to ciprofloxacin. The median duration of treatment was 10 d, median oral dose was 24 mg/kg/d and the median intravenous dose was 15 mg/kg/d. Within 4 d after start of treatment all subjects had a normal body temperature. No subjects had clinical or microbiological relapse and all stool cultures after end of treatment were negative. Adverse events were rare, but in 2 children a transient limb/ataxia or a period of confusion were recorded. Both children recovered within a few days without sequelae. We conclude that ciprofloxacin was effective and well tolerated for treatment of typhoid fever in children. The few adverse events that were recorded left no permanent sequelae, and were likely to be caused by the disease itself.