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Ran Nir-Paz

Publications and source records attributed to Ran Nir-Paz.

10 recordsLinked to original sources
PubMed2006

Identification of risk factors for infection in an outbreak of Mycoplasma pneumoniae respiratory tract disease.

BACKGROUND: Mycoplasma pneumoniae is one of the most common pathogens that causes community-acquired respiratory tract infection. Outbreaks are well known, and all age groups are susceptible. An outbreak in an army training unit afforded an opportunity to identify possible risk factors for morbidity. METHODS: An outbreak of respiratory illness that occurred in a unit comprising 91 trainees was investigated and analyzed as a cohort study. M. pneumoniae infection was suspected on clinical grounds and was confirmed by polymerase chain reaction, culture, and serologic testing. Data regarding medical history, symptoms, signs, and laboratory tests were collected. RESULTS: During a period of 12 days, 41 soldiers (45.1%) had respiratory illnesses, of which 10 (11.0%) were pneumonia. Comparison of symptomatic and asymptomatic individuals revealed that smoking was associated with higher rates of disease (risk ratio, 2.1; 95% confidence interval [CI], 1.3-3.2; P<.005) and seroconversion (risk ratio, 2; 95% CI, 1.2-3.4; P=.03). In multivariate analysis, both lower acute immunoglobulin G values (adjusted odds ratio, 7.8; 95% CI, 1.4-42.5; P=.018) and smoking (adjusted odds ratio, 5.6; 95% CI, 1.5-20.4; P=.01) were associated with symptomatic infection; stratification according to smoking status revealed that immunoglobulin G levels among nonsmokers were protective. Patients who had pneumonia had lower lymphocyte counts (1400+/-258 vs. 2000+/-465 cells/microL; P=.001). CONCLUSIONS: Smoking and lower preexisting immunoglobulin G levels were strongly associated with M. pneumoniae respiratory infection. These findings emphasize the importance of immunity and cessation of smoking for the prevention of disease. The high attack rate emphasizes the extent of infection transmission among healthy persons living in close contact.

Cohort Studies↗
PubMed2006

Macrolide, lincosamide and tetracycline susceptibility and emm characterisation of invasive Streptococcus pyogenes isolates in Israel.

Group A beta-haemolytic streptococcus (GAS) causes a variety of infections, including life-threatening illnesses. Although the species is uniformly penicillin susceptible, resistance to other antibiotics is becoming more common. We studied the prevalence of resistance and associated factors in a nationwide, prospective, population-based study of invasive infections in Israel. Isolates were collected in collaboration with 24 hospitals in Israel during 1996-1999. Minimal inhibitory concentrations (MICs) of erythromycin (ERY), clindamycin (CLI) and tetracycline (TET) were determined as well as ERY and TET resistance phenotypes and genotypes. Five hundred isolates were examined: 136 (27.2%) were not susceptible to TET, 10 (2.0%) to ERY and 5 (1%) to CLI. ERY resistance was associated with emm types 12 and 83 (P<0.001 for both). MICs of TET had a bimodal distribution distinguishing sensitive and resistant populations. Non-susceptibility to TET was mainly due to the presence of tet(M) and was associated with T types 3, 3/13/B3624 and 9 and emm types 9, 33, 64, 73, 74, 76, 77 and 83. TET susceptibility was associated with T types 1, 2 and 11, emm types 1-4, 11, 12, 22, 26 and 75 and the presence of speA and speC. In Israel, resistance of invasive GAS isolates to ERY remains low and is associated with specific T and emm types, as is TET resistance. TET resistance is less frequent than previously reported in Israel and is associated with a lower prevalence of speA and speC.

Anti-Bacterial Agents↗
PubMed2006

Massive empyema caused by Mycoplasma pneumoniae in an adult: a case report.

BACKGROUND: Mycoplasma pneumoniae is responsible for more than 20% of community acquired pneumonia cases, and capable of causing upper respiratory illness as well. Complications of M.pneumoniae infections include CNS involvement but other as pericarditis were also reported. The lack of feasible culture methods and under appreciation of the pathogens ability to cause invasive disease leads to reduced number of diagnosed M.pneumoniae related complications. In contrast to many other respiratory pathogens causing pneumonia, M. pneumoniae related severe pleural complications were almost never reported. CASE PRESENTATION: We report a previously healthy 57 years old woman presented with indolent massive right pleural effusion, leukocytosis and elevated ESR. Extensive microbiological evaluation didn't reveal any pathogen in the pus even before antibiotic treatment was started. Surprisingly, M.pneumoniae DNA was detected in the pus from the empyema using PCR designed to detect M.pneumoniae. A serological assay (Serodia-Myco II) using convalescent serum was indeterminate with a titer of 1:80. The patient responded well to a treatment that included right thoracotomy with pleural decortication and a combination of antibiotics and anti-inflammatory medications. CONCLUSION: M.pneumoniae related empyema was never reported before in adult patients and was reported in only a few pediatric patients. In our patient there was no evidence to any common pathogens even before initiating antibiotic treatment. The only pathogen detected was M.pneumoniae. In this patient, serology was not helpful in establishing the diagnosis of M.pneumoniae related diseases, as was suggested before for older patients. We suggest that M.pneumoniae related empyema is probably under-diagnosed complication due to insensitivity of serology in older patients and under use of other diagnosis methods.

Anti-Bacterial Agents↗
PubMed2004

Clinical and epidemiological aspects of infections caused by fusarium species: a collaborative study from Israel.

Fusarium infections are an important problem worldwide, commonly affecting immunocompromised individuals. We conducted a retrospective study in two Israeli tertiary medical centers of factors predisposing to infection by Fusarium spp. and their influence on the epidemiology and clinical outcome of this infection. Fusarium spp. were isolated from 89 patients with a median age of 57 years. Sixty-eight patients were considered immunocompetent. Seven patients had disseminated disease, 34 had locally invasive disease, and 48 had superficial infection. Most infections were limited and occurred mainly in lower limbs. Factors associated with in-hospital mortality were chronic renal failure, hematological malignancy, immunosuppression, disseminated infection, and positive blood culture. Multivariate analysis showed that chronic renal failure, hematological malignancy, burns, and disseminated infection were independently associated with mortality. A surge in the frequency of infections was noticed during the summer for patients from rural areas, involving mainly the eyes and lungs. At one of the hospitals (in a mountainous area), there was an increase in the isolation rate over time.

Adolescent↗
PubMed2004

Group G streptococcal bacteremia in Jerusalem.

Group G Streptococcus (GGS) can cause severe infections, including bacteremia. These organisms often express a surface protein homologous to the Streptococcus pyogenes M protein. We retrospectively studied the characteristics of patients from the Hadassah Medical Center with GGS bacteremia from 1989 to 2000. Ninety-four cases of GGS bacteremia were identified in 84 patients. The median age was 62 years, 54% were males, and 92% had underlying diseases (35% had a malignancy, and 35% had diabetes mellitus). The most frequent source for bacteremia was cellulitis (61%). emm typing of 56 available isolates disclosed 13 different types, including 2 novel types. Six patients had recurrent bacteremia with two to four bacteremic episodes, five had chronic lymphatic disorders, and two had emm type stG840.0 in every episode. Recurrent bacteremia has not been described for invasive group A Streptococcus. We describe an entity of recurrent GGS bacteremia, which is associated with lymphatic disorders and possibly with emm stG840.0.

Adolescent↗
PubMed2003

emm typing of M nontypeable invasive group A streptococcal isolates in Israel.

We performed emm typing of M nontypeable invasive group A streptococcal (GAS) isolates collected in a prospective population-based study in Israel. One hundred twenty of 131 isolates (92%) had emm sequences compatible with GAS, consisting of 51 different emm types. Eleven isolates were found to be group G streptococcus. Of the 120 isolates, 55 (46%) belonged to 32 types for which there were no typing sera available in the Streptococcal Reference Laboratory in Israel. The other 65 (64%) isolates, consisting of 19 types, had sera available and therefore could have been serotyped. Forty-three isolates had T and emm types which were not correlated according to standard M-typing protocols and were therefore missed. The principal effect of emm typing was the addition of 32 types not previously identified in Israel and the discovery of new associations between emm and T types. emm typing did not significantly change the proportion of M types; the five most common types were 3, 28, 2, 62, and 41. Twenty different types comprised 80% of all isolates. No new emm sequences were discovered. emm typing emphasized the unusually low incidence of M1 strains causing severe disease in Israel. As serological typing of GAS becomes more problematic due to lack of sera and the appearance of new emm types, reference laboratories should replace M typing with emm sequence typing. Development of a GAS vaccine relies on the emm type distributions in different geographical locations. In our study, 7% of isolates (types 41 and 62) are not included in a 26-valent vaccine that is being studied.

Antigens, Bacterial↗
PubMed2003

Deep infection by Trichophyton rubrum in an immunocompromised patient.

Dermatophytes are common pathogens of skin but rarely cause invasive disease. We present a case of deep infection by Trichophyton rubrum in an immunocompromised patient. T. rubrum was identified by morphological characteristics and confirmed by PCR. Invasiveness was apparent by histopathology and immunohistochemistry. The patient was treated successfully with itraconazole.

Antibodies, Fungal↗
PubMed2002

Susceptibilities of Mycoplasma fermentans and Mycoplasma hyorhinis to membrane-active peptides and enrofloxacin in human tissue cell cultures.

Mycoplasmas, which are bacteria that are devoid of a cell wall and which belong to the class Mollicutes, are pathogenic for humans and animals and are frequent contaminants of tissue cell cultures. Although contamination of cultures with mycoplasma can easily be monitored with fluorescent dyes that stain DNA and/or with molecular probes, protection and decontamination of cultures remain serious challenges. In the present work, we investigated the susceptibilities of Mycoplasma fermentans and Mycoplasma hyorhinis to the membrane-active peptides alamethicin, dermaseptin B2, gramicidin S, and surfactin by growth inhibition and lethality assays. In the absence of serum, the four peptides killed mycoplasmas at minimal bactericidal concentrations that ranged from 12.5 to 100 microM, but in all cases the activities were decreased by the presence of serum. As a result, under standard culture conditions (10% serum) only alamethicin and gramicidin S were able to inhibit mycoplasma growth (MICs, 50 microM), while dermaseptin B2 and surfactin were ineffective. Furthermore, 8 days of treatment of HeLa cell cultures experimentally contaminated with either mycoplasma species with 70 microM enrofloxacin cured the cultures of infection, whereas treatment with alamethicin and gramicidin S alone was not reliable because the concentrations and treatment times required were toxic to the cells. However, combination of alamethicin or gramicidin S with 70 microM enrofloxacin allowed mycoplasma eradication after 30 min or 24 h of treatment, depending on the mycoplasma and peptide considered. HeLa cell cultures experimentally infected with mycoplasmas should prove to be a useful model for study of the antimycoplasma activities of antibiotics and membrane-active peptides under conditions close to those found in vivo.

Anti-Bacterial Agents↗
PubMed2002

Sex differences in giant cell arteritis.

OBJECTIVE: Although it has been suggested that sex differences underlie the varying presentation of giant cell arteritis (GCA), this has not been proven. We compared medical history, symptoms, and signs in patients with GCA and polymyalgia rheumatica (PMR). METHODS: We performed a retrospective study in the Hadassah University Hospitals in Jerusalem, Israel. We evaluated medical data of 88 patients (59 women, 29 men) admitted with the diagnosis of GCA or PMR between 1980 and 1998. RESULTS: Comparison of comorbidities among patients showed that non-insulin dependent diabetes mellitus, cerebrovascular accidents, and chronic renal failure are more prevalent in men, while hypertension has a trend to be more prevalent in women. In the clinical presentation of the disease, eye involvement is more prevalent in men, with a tendency towards blindness. Women tend to have higher prevalence of jaw involvement and complaints of polymyalgia. The sexes also seem to differ with respect to laboratory presentation of the disease. CONCLUSION: Men and women with GCA and PMR differ in their history, presentation, and laboratory findings. Our results recommend a more aggressive approach to male patients in view of the higher prevalence of severe eye involvement and blindness.

Aged↗