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PubMed1993

Low-dosage cefepime as treatment for serious bacterial infections.

Since infection develops in significant numbers of hospitalized patients, the problem of resistance to third-generation cephalosporins is of increasing concern. We evaluated the efficacy of cefepime 1 g bd as treatment for acute, moderately severe bacterial infection in 239 hospitalized patients (mean age 60 years). Of these patients, 204 were evaluated clinically for urinary tract infection (UTI) (n = 90), lower respiratory tract infection (LRTI) (n = 70), skin and soft tissue infection (S/STI) (n = 12) and bacteraemia which was associated with either UTI or LRTI (n = 32) but not included in the previously mentioned UTI and LRTI groups. Amongst the pathogens isolated (36 Gram-positive, 150 Gram-negative), the most predominant species were Escherichia coli in UTI and bacteraemia (n = 81), Streptococcus pneumoniae in LRTI and bacteraemia (n = 23), Haemophilus influenzae in LRTI (n = 16), Pseudomonas aeruginosa (n = 4) and Enterobacter cloacae (n = 2) in S/STI. The mean duration of treatment was 8.5 days and was the same for the 204 clinically evaluable patients. Overall, the clinical cure rate for cefepime was 94% (191/204). Pathogen eradication was achieved in 93% (185/199) of infections. Of the patients with associated bacteraemia, the clinical cure rate was 97% (31/32) and 94% (16/17) of the pathogens were eradicated. Cefepime therapy was well-tolerated. Treatment was discontinued in eight patients (3%) because of local intolerance and in five patients (2%) because of drug-related adverse events (rash, headache and pruritus). Cefepime 1 g bd is as safe and effective as other parenteral cephalosporins for the treatment of acute bacterial UTI, LRTI and S/STI, including those cases with associated bacteraemia. The bd dosing schedule and reported lack of cross-resistance with other cephalosporins against some species of aerobic Gram-negative bacilli make cefepime an attractive treatment option in hospitalized patients.

Adolescent↗
PubMedDate not supplied

[Fatty acids composition of cellular lipids of the collected and newly isolated Pseudomonas lupini strains].

Fatty acid composition of cellular lipids of 23 Pseudomonas lupini strains (Beltjukova et Koroljova 1968) has been investigated. Cellular fatty acids which contained from C10 to C19 carbon atoms have been identified. Basic fatty acid of those Pseudomonas cells are hexadecanoic, hexadecenoic and octadecanoic acids. The 3-hydroxydecanoic (C10:0 3OH), 3-hydroxydodecanoic (C12:0 3OH), 2-hydroxydodecanoic (C12:0 2OH) and cyclopropane fatty acids which contain 17 and 19 carbon atoms have been detected in cellular lipids. The cellular fatty acids spectra of 22 P. lupini strains are similar to cellular fatty acids spectrum of the type strain Pseudomonas syringae pv. syringae 8511. Pathogenic isolate 2, which fatty acid content of cell lipids significantly differ from lipids of cell fatty acids from P. lupini strains and cell lipids of fatty acids of typical strains Pseudomonas syringae pv. syringae 8511 and Pseudomonas savastanoi pv. phaseolicola 9066 is the exception.

Carbohydrate Conformation↗
PubMed2005

[Susceptibility of the bacteria isolated from samples of clinical material in Poland in 1998 to selected chemotherapeutics and antibiotics--the analysis of the questionnaire findings. I. Susceptibility of staphylococci].

The work has been undertaken in order to attain detailed information on the antibiotic sensitivity of the identified microorganisms from different clinical material derived from inpatients, outpatients and healthy people, on various regions of Poland in 1998. Approprite questionnaires (cards) were sent to each sanitary-epidemiological stations throughout Poland. Received 28619 cards, from 44 Public Health Service laboratories, allowed to create a computerized data base in Department of Bacteriology in National Institute of Hygiene in Warsaw. Staphylococci were the most frequent etiologic pathogen isolated from the clinical material--24,7%. Among them, there were: S. aureus--75,8%, S. epidermidis--9,7%, unidentified coagulase negative staphylococci (CNS)--9,2% and S. saprophyticus--5,1%. 71,6% of staphylococci strains derived from non-hospital material and 26,7% from hospital material. Staphylococci strains isolated from inpatients specimens were more resistant to antibiotics than those from outpatients specimens. The highest resistance, among both hospital and non-hospital strains, was exhibited to penicillin (70-100%) and tetracycline (approximately 50%); the lowest to: glycopeptides, ciprofloxacin, trimethoprim/sulfametoxazole, nitrofurantoin and gentamicin. Staphylococci isolated from various clinical specimens differed in their antibiotic resistance. The percentages of coagulase-negative staphylococci strains resistant to the antibiotics used were higher than of S. aureus strains. On the average 34% of S. aureus strains were methicillin-resistant (MRSA); but depending on specimens were isolated from, it ranged from 24% of MRSA strains for ear and nose swabs to 70% of MRSA strains for feaces samples. Among MRSA strains the percentage of resistance to other antibiotics was a few time higher than among MSSA strains. The territorial distribution of staphylococci strains resistance to various antibiotics in Poland is not uniform.

Anti-Bacterial Agents↗
PubMed2000

Endemic carbapenem-resistant Acinetobacter species in Brooklyn, New York: citywide prevalence, interinstitutional spread, and relation to antibiotic usage.

Acinetobacter species are problematic nosocomial pathogens. In November 1997, pathogens isolated by microbiology laboratories were collected from 15 hospitals in Brooklyn, New York. Acinetobacter species accounted for 10% of gram-negative isolates. Only half of Acinetobacter species were susceptible to carbapenems; 11 hospitals had at least 1 isolate resistant to carbapenems. Other Acinetobacter susceptibility rates were as follows: polymyxin, 99%; amikacin, 87%; ampicillin/sulbactam, 47%; ceftazidime, 25%; and ciprofloxacin 23%. Overall, 10% were resistant to all commonly used antibiotics. Genetic analysis by use of pulsed-field gel electrophoresis of 12 carbapenem-resistant isolates revealed 4 strains that were recovered from >1 hospital, which suggests interinstitutional spread. Antibiotic usage data from 11 hospitals revealed that the use of third-generation cephalosporins was associated significantly with the percentage of carbapenem-resistant strains (P=.03). Resistant Acinetobacter species have become endemic in Brooklyn, New York. Citywide strategies that involve surveillance, infection-control practices, and the reduction of antibiotic usage may be necessary to control the spread of these pathogens.

Acinetobacter↗
PubMed1987

The electrophoretic isoenzyme patterns of strains of Entamoeba histolytica isolated in two major cities in Canada.

The isoenzyme patterns of 92 isolates of Entamoeba histolytica from British Columbia and 28 from Ontario were determined. Seropositivity for E. histolytica was assessed by indirect hemagglutination and enzyme-linked immunosorbent assay in the one center and by ELISA and amebic gel diffusion in the other. In both British Columbia and Ontario nonpathogenic zymodemes I and III were most common. A newly described isoenzyme pattern was identified in Ontario. Only 9 of 120 zymodeme patterns identified were found to be pathogenic strains of E. histolytica. Pathogenic isolates were strongly correlated with clinical symptoms and seropositivity.

Animals↗
PubMed1991

Normal vaginal aerobic and anaerobic bacterial flora of the rhesus macaque (Macaca mulatta).

The most common bacterial species isolated from the vaginas of 37 healthy rhesus macaques were Streptococcus viridans, coagulase negative Staphylococcus, Mobiluncus curtisii ss. curtisii, Corynebacterium renale-like organisms, Peptostreptococcus anaerobius, Gardnerella-like organisms, and other Corynebacterium species. The vaginal flora of the rhesus macaque differs from that previously reported for five other primate species. A two-year retrospective review of clinical cases of vaginitis and metritis found Escherichia coli and coagulase positive Staphylococci to be the most common pathogens isolated.

Animals↗
PubMed2000

Efficacy and safety of ten day moxifloxacin 400 mg once daily in the treatment of patients with community-acquired pneumonia. Community Acquired Pneumonia Study Group.

Community-acquired pneumonia (CAP) remains a common and serious illness with approximately 2-4 million cases reported annually. Management of CAP is therapeutically challenging due to the increasing prevalence of penicillin- and macrolide-resistant pneumococci and beta-lactamase producing Haemophilus influenzae, as well as the increased recognition of 'atypical' pathogens, such as Chlamydia pneumoniae and Mycoplasma pneumoniae, and the frequent need for empiric therapy. We aimed to evaluate the safety and efficacy of moxifloxacin in the treatment of patients with CAP. To do this we carried out a prospective, uncontrolled, non-blind, Phase III clinical trial, in 27 U.S. centers. Patients included in the study were over 18 years of age with signs and symptoms of CAP confirmed by evidence of a new or progressive infiltrate on chest radiograph. The intervention used was moxifloxacin 400 mg PO once daily for 10 days. Sputum samples were collected pretherapy for Gram stain and culture for typical organisms. Culture and serological testing for Chlamydia pneumoniae and Mycoplasma pneumoniae was also performed. Susceptibility to moxifloxacin was determined by disk diffusion and MIC. Clinical and bacteriological responses were determined at the end of therapy (0-6 days post-therapy), follow-up (14-35 days post-therapy) and overall (end of therapy plus follow-up). Analyses were performed on both valid for efficacy and intent-to-treat populations. The primary efficacy variable was overall clinical resolution. Of 254 patients enrolled in the Study, 196 patients were included in the efficacy analyses. The majority of patients were male (58%) and Caucasian (85%) with a mean age of 49 years (range: 18 to 85 years). Only 3% of patients were hospitalized pretherapy. The most common pretherapy organisms identified, by culture or serology, in the valid for efficacy population (i.e. 147 organisms among 116 patients), were: Chlamydia pneumoniae (n=63; 54%), Mycoplasma pneumoniae (n=29; 25%), Streptococcus pneumoniae (n=14; 12%) and Haemophilus influenzae (n=13; 10%). End of therapy, follow-up and overall clinical resolution rates for the valid for efficacy population were 94%, 93% and 93%, respectively. The 95% CI for the overall clinical resolution rate was 88.1%, 95.9%. The overall bacteriological response for patients diagnosed by culture or serological criteria, was 91% (95% CI=84%, 96%). For patients who only met serological criteria for infection, the overall bacteriological response was 94% (60/64). Bacterial response rates for the four most commonly isolated pathogens were: 89% (56/63) for C. pneumoniae, 93% (27/29) for M. pneumoniae, 93% (13/14) for S. pneumoniae and 85% (11/13) for H. influenzae. Drug-related adverse events were reported in 33% (85/254) of moxifloxacin-treated patients. Nausea (9%), diarrhea (6%) and dizziness (4%) were the most commonly reported adverse events. Atypical organisms were isolated in high frequency among patients with CAP. Moxifloxacin 400 mg once daily for 10 days was effective and well-tolerated in the treatment of these adult patients with CAP. Moxifloxacin offers an effective treatment alternative for CAP due to both typical and atypical bacterial pathogens.

Adolescent↗
PubMed1999

Janthinobacterium agaricidamnosum sp. nov., a soft rot pathogen of Agaricus bisporus.

A novel bacterium has been found that causes a soft rot disease of Agaricus bisporus, the cultivated mushroom. It has been characterized using nutritional, physiological, chemical and molecular techniques. Based on these data, it was shown to have many characteristics in common with members of the genus Janthinobacterium. Despite similarities to the only described species within this genus, Janthinobacterium lividum, there were a number of differences between the mushroom pathogen isolated and this species. Despite the high degree of genotypic similarity between members of the genus Janthinobacterium and Herbaspirillum, as evidenced by DNA-RNA hybridization, and the high degree of 16S rDNA sequence similarity between members of the genera Janthinobacterium, Herbaspirillum, Oxalobacter and Duganella, as well as the generically misnamed Pseudomonas lemoignei, it was possible to show that members of the genus Janthinobacterium could be easily distinguished from these taxa. The data also indicated that the mushroom pathogenic strains represent a novel species within the genus Janthinobacterium for which the name Janthinobacterium agaricidamnosum sp. nov. is proposed. The type strain of this species has been deposited in the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Braunschweig, Germany, as DSM 9628T and at the National Collection of Plant-pathogenic bacteria, UK, as NCPPB 3945T. To aid practical control of the disease, the effect of the relative humidity on symptom expression on Agaricus bisporus was determined.

Agaricus↗
PubMed2004

Otitis media in dairy calves: a retrospective study of 15 cases (1987 to 2002).

Epidemiological data, clinical signs, complementary examination findings, antimicrobial treatments, and outcome were reviewed in 15 calves diagnosed with otitis media at the Centre hospitalier universitaire vétérinaire de l'Université de Montréal between 1987 and 2002. Age at presentation ranged from 2 to 18 weeks. A purulent ear discharge and epiphora were seen in 8/12 and 6/15 cases, respectively. Neurological signs observed were head tilt (13), eyelid ptosis (7), paresis/paralysis of the pinna (8), ataxia (2), strabismus (2), and convulsions (1). Concurrent pneumonia was frequently diagnosed (n = 11). A Mycoplasma sp. was the principal pathogen isolated from ear discharge; 6 out of 6 samples submitted were positive for mycoplasma. Tympanic bullae radiographs were considered abnormal in 12 out of 13 cases. Cerebrospinal fluid analysis was considered abnormal in 2 out of 5 cases. The antibiotic most commonly used was enrofloxacin (n = 7). Average treatment duration was 19.6 days. Four out of 8 treated animals for which follow-up information was available completely recovered. These results suggest that M. bovis is a major pathogen of otitis media in dairy calves and effective antimicrobial therapy should be of long duration.

Animals↗
PubMed2005

Experimental infection of macaques with the human reovirus BYD1 strain: an animal model for the study of the severe acute respiratory syndrome.

Experimental studies were performed to determine the role of a newly isolated reovirus (ReoV) from a severe acute respiratory syndrome (SARS) patient in the etiology of this newly described serious respiratory syndrome. Four cynomologus macaques were inoculated with this reovirus (BYD1) in an attempt to replicate the infection and pathology observed in SARS. The body temperature of the infected monkeys was monitored three times a day, and blood and fecal samples were periodically collected for specific immunology determinations. On days 7 and 33 after inoculation, necropsies for pathological accessment and pathogen isolation were performed. The four infected macaques developed a fever on days 3 and 4 after inoculation, and maintainted a febrile state for 4-6 days. The highest temperature in the animals recorded was 40.4 degrees C. After a recovery phase, the macaques developed a second febrile condition. Antibody titers against the reovirus injected by the intravenous route occurred in higher number than those in the nasal cavity. Four macaque monkeys demonstrated diffuse alveolar damage, characterized by hemorrhagic pneumonia, serosanguineous exudates, formation of hyaline membranes, and type II pneumocyte hyperplasia, which were similar to those that have been noted in SARS patients. Lymphocytes decreased in the cortex of the lymph node and in the white pulp of the spleen. ReoV was detected in pneumonic tissue by virus isolation and RT-PCR. The macaques infected with the newly isolated reovirus developed a fever, diffuse alveolar damage and pulmonary interstitial inflammation similar to that noted in SARS patients. This evidence demonstrates that ReoV might have a primary role in the etiology of SARS.

Animals↗
PubMed1997

In vitro activity of fosfomycin trometamol against pathogens from urinary tract infections: a Spanish multicenter study.

The in-vitro susceptibilities of a total of 1371 urinary tract pathogens to fosfomycin trometamol were determined. According to the NCCLS breakpoints, Enterobacteriaceae and gram-positive microorganisms were, in general, very sensitive to this antimicrobial. More than 90.0% of the Escherichia coli and Citrobacter spp. and more than 70.0% of the Klebsiella pneumoniae, K. oxytoca, Enterobacter spp., Proteus mirabilis, Staphylococcus aureus, coagulase-negative staphylococci and Enterococcus spp. strains tested were susceptible to fosfomycin trometamol. However, Pseudomonas aeruginosa and Acinetobacter spp. strains were more resistant. In general, recent clinical isolates from urinary tract infections (UTIs) in both community and hospital were also very sensitive (> 80.0%) to fosfomycin, its activity being higher than that of the rest of the antimicrobials commonly used for therapy of uncomplicated UTIs. More than 75.0% of the most frequently isolated pathogens from UTIs, except for P. aeruginosa (31.8%) and Acinetobacter spp. (11.1%), were susceptible to fosfomycin trometamol. The results obtained in this study, together with the infrequency of side effects and its pharmacokinetic properties, indicate that fosfomycin trometamol may be a useful alternative for single-dose therapy of uncomplicated UTIs.

Anti-Bacterial Agents↗
PubMed1990

Lyme borreliosis in laboratory animals: effect of host species and in vitro passage of Borrelia burgdorferi.

The susceptibility of several common laboratory animal species to a known pathogenic isolate of Borrelia burgdorferi (N40) was evaluated following intraperitoneal (ip) inoculation of 10(6-8) spirochetes into 3-day-old Lewis rats, CD-1 mice, Syrian hamsters, and 3-week-old American Dutch rabbits. At 30 days, tissues were cultured for spirochetes and examined histologically. All species developed multisystemic infection as well as arthritis and carditis, but disease was most severe in rats and mice. In order to evaluate the effect of in vitro passage on the pathogenicity of B. burgdorferi, 3-day-old Lewis rats were inoculated ip with borreliae passaged in culture 2, 5, 11, 17, 21, 26, and 31 times, and evaluated at 30 days by culture, histology, and ELISA antibody titers. Based upon these parameters, B. burgdorferi (N40) lost its virulence at 17-21 passages. This study demonstrated that B. burgdorferi was infectious for infant rats, mice, hamsters, and 3-week-old rabbits, although pathogenicity was modulated by host species and the in vitro passage history of the spirochete. Of the 4 laboratory animal species evaluated in this study, rats and mice appear to have the most potential for further use as animal models of Lyme disease.

Animals↗
PubMed2002

Comparative in vitro activities of ertapenem against aerobic and facultative bacterial pathogens from patients with complicated skin and skin structure infections.

This study compared the in vitro activities of ertapenem (Merck & Co., Inc.), ceftriaxone, amoxicillin-clavulanate, and piperacillin-tazobactam against 518 aerobic and facultative bacterial pathogens isolated from 340 patients with complicated skin and skin structure infections. Ciprofloxacin was also tested against Gram-negative isolates. Gram-positive cocci accounted for 68.1% of the aerobic bacteria; Staphylococcus aureus was the most common isolate (45.6%). The ertapenem MIC was < or = 2 microg/ml for 80.9% of isolates and > or = 8 microg/ml for 16.2% (including isolates of enterococci, methicillin-resistant S. aureus, Pseudomonas aeruginosa, and other nonfermentative Gram-negative bacteria). Against methicillin-susceptible S. aureus, ertapenem had the most potent activity. Ertapenem was the most active drug against Enterobacteriaceae (100% susceptible), whereas amoxicillin-clavulanate was least active (66% susceptible). Piperacillin-tazobactam was the most active drug against P. aeruginosa (100% susceptible), followed by ciprofloxacin (87% susceptible). In summary, ertapenem was highly active in vitro against many aerobic and facultative bacterial pathogens commonly recovered from patients with complicated skin and skin structure infections.

Aerobiosis↗
PubMed1996

Antibiotic-resistant enterococci and the changing face of surgical infections.

BACKGROUND: Enterococci have not been thought to play an important role in intra-abdominal infections because of their relatively low virulence. However, this notion is changing because of the recent emergence of these microbes as significant nosocomial pathogens. OBJECTIVES: To review the mechanisms of antibiotic resistance of enterococci and to discuss the significance of multidrug-resistant enterococci in surgical infections. DATA SOURCES: Medical and basic science literature relating to enterococci. DATA SYNTHESIS: In addition to having intrinsic resistance to a number of antibiotics, enterococci have the ability to acquire resistant genes through the exchange of plasmids or transposons from other bacterial species. Moreover, enterococci have been shown to transmit these genes to other bacterial species in turn. The extensive resistance of these microorganisms has led to their emergence as significant nosocomial pathogens, ranking second only to Escherichia coli in the number of pathogenic isolates recovered from patients in intensive care units. There has also been a marked increase in vancomycin-resistant enterococcal infections in surgical patients in the last 5 years. Some studies associate the prior use of vancomycin or third-generation cephalosporins with the emergence of these strains. Overall, enterococcal infections are associated with increased morbidity and mortality. CONCLUSIONS: In view of the marked resistance of enterococci to antibiotics and their ability to disseminate resistance genes, these microbes have become important pathogens. Enterococci pose a threat to surgical patients, often causing significant therapeutic dilemmas.

Drug Resistance, Microbial↗
PubMed1985

[Bacteriological, pharmacokinetic and clinical studies on aztreonam in the pediatric field. Pediatric Study Group of Aztreonam].

This report summarizes the results of joint studies in pediatrics on aztreonam, the first monobactam antibiotic for practical use. Pharmacokinetics was studied in 53 cases administered with 10, 20, 40 and 50 mg/kg of aztreonam (AZT) by intravenous injection and 20 cases with 10, 20, 30, and 40 mg/kg by drip infusion. All the cases had normal hepatic and renal functions at the administration. T1/2 was in a relatively fixed range of 1.35-1.56 hours in intravenous injection cases and 1.30-1.55 hours in drip infusion. One hour after commencing administration of standard 20 mg/kg, the serum concentrations were 50.18 +/- 4.24 micrograms/ml in intravenous injection and 116.33 +/- 10.18 micrograms/ml in drip infusion and even 6 hours after the end of the administration, they were 5.80 +/- 1.16 micrograms/ml and 3.38 +/- 0.58 micrograms/ml, respectively. The cerebrospinal fluid penetration was studied on suppurative meningitis (5 cases) and nonbacterial meningitis (3 cases). The penetration was generally good with sufficient concentration for meningitis caused by E. coli and H. influenzae. Amount of the penetration decreased as the cases were improved. Twenty-nine (29) cases were excluded and 262 cases of total 291 were clinically assessed, and the pathogen-isolated 167 cases of 262 were principally analyzed. Efficacy of AZT was "excellent" for all 3 cases of E. coli sepsis and 1 case of N. meningitidis meningitis and "good" for 1 case of H. influenzae meningitis. The effective rate was 94.6% for 37 pneumonia cases, 94.7% for 76 UTI cases and 88.5% on the whole including as many as 98 "excellent" cases. However, the effective rate for 21 enteritis cases was only 52.4%. Similar trend was observed in the pathogen-unknown group and overall effective rate of total 267 cases was 86.8%. The clinical effect by pathogen was 97.7% for 44 E. coli cases and 97.1% for 34 H. influenzae cases, showing excellent results for the GNB group. AZT was also effective for 8 out of 11 P. aeruginosa cases. With regard to microbiological effect by pathogen, AZT showed a high rate of bacterial elimination for GNB, primarily 98.1% for E. coli and 100% for H. influenzae followed by 76.9% for P. aeruginosa. However, it was only 30.0% for Salmonella. Excluding the Salmonella cases, GNB elimination rate was 93.5%. Clinical and microbiological dose response was not clear partly because, same as the previous studies, the effective rate of AZT was high. It was considered, however, standard dose of 20 mg/kg X 3 approximately 4 times a day was recommendable.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Factors↗
PubMed2002

In vitro antibiotic susceptibility of bacteria isolated from EUS-affected fishes in India.

AIMS: Twelve antibiotics were evaluated for in vitro sensitivity against 16 bacterial strains isolated from surface lesions of fishes affected with epizootic ulcerative syndrome (EUS). METHODS AND RESULTS: Disc diffusion assay in Mueller-Hinton agar showed that the pseudomonads and aeromonads were mainly resistant to penicillin, ampicillin and erythromycin. Additionally, some were resistant to gentamycin and amoxycillin. However, resistance towards antibiotics previously recommended for EUS treatment, such as oxytetracycline and chloramphenicol, was not observed. Four aeromonads and two pseudomonads were found to induce ulcers when injected intramuscularly in healthy Anabas testudineus. CONCLUSIONS: All six pathogenic isolates were sensitive towards oxytetracycline, chloramphenicol and nalidixic acid. Oxytetracycline seems to be an effective antibiotic, and further investigations to determine the mode of treatment and dose appear to be worthwhile.

Animals↗
PubMed2026

Surface architecture of the bacterial envelope determines phage adsorption route in pathogenic Escherichia coli O157:H7.

UNLABELLED: The outermost surface layers of Gram-negative bacteria determine phage access to terminal receptors, yet their genetic basis has been mapped almost exclusively in laboratory strains that lack them. Here we apply genome-wide RB-TnSeq fitness profiling to four Escherichia coli O157:H7 strains from distinct phylogenetic clades sharing the O157 O-antigen, using 38 phages with terminal receptors previously mapped in E. coli K-12 strain. RB-TnSeq fitness landscapes across all four pathogenic backgrounds were mostly similar, and dominated by surface-associated loci, including the gfc-etk group 4 capsule operon, O-antigen biosynthesis genes, LPS core assembly genes and outer membrane proteins. Disruption of gfc-etk abolished infection in 11 genetically diverse myoviruses, establishing the O-antigen capsule as a widespread required primary recognition substrate. O-antigen loci generated two classes of fitness score patterns. For 10 phages, disruption increased infectivity, indicating it is a barrier to receptor access; for 3 others, disruption abolished infectivity, demonstrating it can also be a primary recognition substrate. Outer membrane protein receptor identity was conserved across laboratory and pathogenic backgrounds, with the same proteins recognized in both K-12 and O157:H7, while glycan layer state determines whether these receptors are reached. These results demonstrate that outer surface glycan layers can act as primary and optional recognition substrates for phage infection, or as physical barriers preventing terminal receptor access. Extending the ability to probe phage-targeted receptors beyond outer membrane proteins provides a framework for incorporating glycan layer state into predictive models of phage-host interactions. IMPORTANCE: Bacteriophage-based interventions for controlling Escherichia coli O157:H7, a major foodborne pathogen responsible for tens of thousands of illnesses annually in the United States, require a mechanistic understanding of the factors governing strain-level susceptibility. Predictive frameworks developed in laboratory model strains lacking O-antigen and capsular polysaccharides can map the terminal protein receptors that phages bind, but are currently limited in their ability to determine whether those receptors are accessible in pathogenic isolates carrying full outer surface complexity. This study provides the first genome-scale, functional genetic map of phage susceptibility determinants in O157:H7 and demonstrates that the state of the outer surface layers, specifically the O-antigen and the gfc-etk capsule, determines whether phages can reach conserved terminal receptors. This finding explains differences in phage susceptibility between strains sharing nearly identical gene content, and identifies the molecular layers that must be characterized to predict phage host interaction in pathogenic E. coli backgrounds.

Journal Article↗
PubMed2004

[Some epidemiologic characteristics of foodborne intoxications in Croatia during the 1992-2001 period].

Epidemiologic characteristics of foodborne intoxications registered in Croatia during the 1992-2001 period are described. Salmonellosis, as well as staphylococcal food intoxication, foodborne botulism, Clostridium perfringens food intoxication, histamine poisoning and food intoxication caused by other pathogens, especially conditionally pathogenic bacteria, were analyzed. During the study period, 87,782 cases were reported, 45,721 (52.1%) of them related to salmonellosis and the rest of 42,061 (47.9%) cases to foodborne intoxications of various etiology. The diseases occurred throughout the year, with a higher proportion in summer than at any other time of year. During the study period, 480 outbreaks of foodborne intoxications with 10,567 cases were reported, 405 (84.4%) of them with 8476 cases related to salmonellosis. The most frequently isolated pathogen in salmonellosis outbreaks was Salmonella enteritidis with 345 (85.2%) outbreaks. The outbreaks of salmonellosis were primarily associated with the intake of pastries (40.1%). Ice-cream was associated with a high risk of staphylococcal food intoxication, and bean salad of Clostridium perfringens food intoxication. The food vehicle of transmission most often associated with foodborne botulism outbreaks was smoked ham. Histamine poisoning, recorded in four outbreaks, occurred after consumption of fish and fish products. Salmonellosis outbreaks most frequently occurred at home (n=149; 36.8%), followed by pastry shops with 47 (11.6%) outbreaks, the latter also ranking first in the outbreaks of staphylococcal food intoxication (40%).

Croatia↗