Rapid identification of uropathogens by combining Alfred 60 system with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry technology.

Rapid identification of uropathogens is needed to determine appropriate antimicrobial therapy. This study evaluated performance of the Alfred 60 system combined with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) technology for rapid identification of uropathogens. The Alfred 60 system was used to screen urine cultures, followed by identifying the microbial pathogen in positive cultures using MALDI-TOF MS. The Alfred 60 detected positive cultures by measuring the turbidity of urine samples, which were transferred automatically to vials containing liquid medium and incubated for 3.5 h at 35 °C in the Alfred 60 system. Vials that showed growth were removed and centrifuged. The pellet was subjected to MALDI-TOF MS identification. In parallel, positive urine samples were inoculated onto agar plates for identification by conventional culture. The time required to detect positive urine cultures with Alfred 60 and identify the uropathogens with MALDI-TOF MS ranged from 15 min to 3.5 h. Among 146 positive urine samples tested, conventional cultures showed three culture groups: group 1 included 101 samples with growth of a single type of microorganism; group 2 included 34 samples with 2 types of microorganisms; and group 3 included 11 samples with ≥ 3 types of microorganisms. Direct identification by MALDI-TOF MS was concordant with 95% of the samples in group 1, 100% of the principal microorganism in group 2, but could not identify microorganisms in group 3. This combination of methods provides rapid, reliable microbial identification for most positive urine cultures.

Associations of High-Sensitive Cardiac Troponin T in Healthy Newborns and Prolonged Second Stage of Labor, Neonatal and Maternal Factors: A Prospective Study.

INTRODUCTION: High-sensitivity cardiac troponin T (hs-cTnT) is not used routinely as a diagnostic biomarker in newborns. The high precision of hs-cTnT assays increases the ability to determine small differences in cTnT over time and to detect troponin T elevation; thus, we believe that hs-cTnT assays might improve clinical care. We explored the plausible association between hs-cTnT levels (ng/L) in healthy newborns and prolonged second stage of labor, neonatal, and maternal factors. METHODS: A prospective study was performed among healthy newborns in the Obstetrics and Gynecology Department at Hillel Yaffe Medical Center in Israel in January-June 2021. The sociodemographic characteristics of the participants, maternal age, gravidity, parity, Pitocin use, epidural analgesia, and neonatal anemia were obtained from the electronic medical records. Gestational age was determined by ultrasound biometric measurements. We classified second-stage labor as normal or prolonged using the WHO guidelines. Samples from umbilical cord blood were drawn using syringes rinsed with anticoagulant by a specialist in pediatrics. The remaining blood was used to determine hs-cTnT levels (ng/L), which was defined as a continuous quantitative variable with the median value and the 25th-75th percentiles. RESULTS: Overall, 184 cord blood samples were performed from healthy newborns (60.6% males) with a median hs-cTnT of 39.03 (25th-75th percentiles = 30.53-54.09) ng/L. A multivariable linear regression model showed no significant association between neonatal anemia and hs-cTnT levels (ng/L) (p = 0.8). Gestational age (B coefficient -4.24, p < 0.001) and gravidity (B coefficient -2.41, p = 0.03) were negatively associated with hs-cTnT levels (ng/L), while Pitocin use (B coefficient 6.91, p = 0.04) and prolonged second stage of labor (B coefficient 18.07, p = 0.02) were positively associated with hs-cTnT levels (ng/L). CONCLUSIONS: High hs-cTnT levels (ng/L) were documented in the cord blood of healthy newborns. Hs-cTnT levels were positively correlated with a prolonged second stage of labor and Pitocin use and negatively correlated with longer gestational age and higher gravidity. Hs-cTnT may signify labor-related fetal distress. A larger surveillance study is mandatory to establish this correlation and assess for possible prognostic significance of elevated hs-cTnT in this context.

In-vitro model for bacterial growth inhibition of compartmentalized infection treated by an ultra-high concentration of antibiotics.

BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) are common pathogens encountered in infected cardiovascular-implantable electronic device (CIED). Continuous, in-situ targeted, ultra-high concentration antibiotic (CITA) treatment is a novel antibiotic treatment approach for localized infections. CITA provides sufficient local antibiotic concentrations to heavily infected cavities while avoiding systemic toxicity. AIM: In-vitro confirmation of the efficacy of the CITA treatment approach in simulated compartmentalized infections. MATERIALS AND METHODS: A rapid automated bacterial culture analyzing system) Uro4 HB&L™ (was applied to compare the efficacy of selected antibiotics at a standard minimal inhibitory concentration (1MIC), 4MIC, and CITA at 103MIC, for growth inhibition of high bacterial loads (106 colony-forming-units/ml) of ATCC strains of P. aeruginosa, E. coli, and S. aureus. RESULTS: The addition of gentamicin and amikacin at 1MIC concentrations only temporarily inhibited the exponential growth of E. coli and P. aeruginosa. 4MIC level extended the delay of exponential bacterial growth. Increasing concentrations of vancomycin similarly temporarily delayed S. aureus growth. All tested antibiotics at CITA of 103MIC totally inhibited the exponential growth of the tested bacteria through 72 hours of exposure. (P<0.001). CONCLUSION: In this in-vitro model, CITA at 103MIC effectively inhibited exponential bacterial growth of high loads of P. aeruginosa, E. coli, and S. aureus. This model offers preliminary laboratory support for the benefit of the in-situ antibiotic treatment, providing ultra-high concentrations directly at the compartmentalized infection site, not achievable by the conventional intravenous and oral routes.

Presence of Helicobacter pylori in a sibling is associated with a long-term increased risk of H. pylori infection in Israeli Arab children.

BACKGROUND AND OBJECTIVES: We examined the dynamics of Helicobacter pylori infection between pre-school and school ages and compared the determinants of late acquisition of H. pylori infection with determinants of early and persistent H. pylori infection. METHODS: ELISA was used to detect H. pylori antigens in stool specimens collected from children at preschool age (3-5 years) and from their mothers and siblings in 2004. The children were tested again for H. pylori at school age (6-9 years) in 2007-2009. Household and socioeconomic characteristics were obtained by interviews. RESULTS: The prevalence of H. pylori infection increased from 49.7% (95% CI 42.8, 56.7) in 2004 to 58.9% (95% CI 51.8, 65.6) in 2007-2009. Among children tested in both examinations, 69 (49.3%) had persistent infection, 14 (10.0%) were new cases, 56 (40.0%) remained uninfected, and one (0.7%) had lost H. pylori infection. The approximate annual incidence of infection during 2004-2009 was 5%. Sibling's H. pylori positivity at baseline increased the risk for late acquisition of H. pylori infection; adjusted prevalence ratio (PR) 4.62 (95% CI 0.76, 28.23) (p = .09), while maternal education lowered the risk; adjusted PR 0.84 (95% CI 0.69, 1.01) (p = .06). Sibling's H. pylori positivity was the only significant variable associated with early and persistent H. pylori infection in multivariate analysis. CONCLUSIONS: Most H. pylori infections are acquired at preschool age and transient infection beyond this age is uncommon in this population. Helicobacter pylori-infected siblings are the major reservoir of H. pylori in early and late childhood demonstrating sustained intra-familial transmission of H. pylori.

A new rapid method for detecting extended-spectrum beta-lactamase/AmpC-producing Enterobacteriaceae directly from positive blood cultures using the Uro4 HB&L™ system.

PURPOSE: To evaluate the performance of the Uro4 HB&L™ system in screening ESBL/AmpC-producing Enterobacteriaceae as compared with the resistant test by VITEK 2. The resistance profile of the ESBL-producing bacteria was also evaluated. METHODOLOGY: Blood culture samples were collected at bedside, inoculated directly into BD BACTEC™ culture bottles, and incubated. When microbial growth was found, samples were prepared for identification using MALDI-ToF. The Uro4 HB&L™ system was used for direct detection of ESBL/AmpC-producing bacteria compared with conventional methods. RESULTS: A total of 103 positive blood cultures containing Gram-negative bacteria were tested. Uro4™ HB&L screening results were obtained in up to 6.5 h, with 91.3% concordance with the VITEK2 system, with 85% sensitivity, 95.2% specificity, and 91.1% positive and 90.9% negative predictive values. The resistance profile of ESBL-producing bacteria tested in the present study showed increased resistance ratio to ciprofloxacin, gentamicin, and trimethoprim/sulfamethoxazole. In parallel, susceptibility to amikacin and meropenem was not affected. CONCLUSIONS: The performance of the Uro4 HB&L™ system is acceptable for rapid screening ESBL/AmpC-producing Enterobacteriaceae. The data related to detecting ESBL-producing bacteria are crucial for managing antimicrobial therapy.

Serum separator tube method for matrix-assisted laser desorption/ionization time-of-flight analysis.

BACKGROUND: Without appropriate treatment, bloodstream infections have a high mortality rate. Quicker identification of the microbial pathogen allows the clinician to develop an initial strategy of antimicrobial therapy. Sample preparation protocols for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS; Bruker Daltonics for Microflex LT spectrometer) technology were evaluated in an attempt to identify pathogens directly from positive blood culture bottles and thus shorten the time to identify them. This application requires preparatory processing because blood culture bottles contain undesirable proteins. This study aimed to evaluate two methods for microbial preparation for identification by MALDI-ToF MS. METHODS: This study evaluated two methods for microbial preparation from 200 positive blood culture samples, half prepared by the differential centrifugation method and half with the serum separator tube method for identification by MALDI-ToF MS. Both methods were compared to conventional methods such as VITEK II and ChromAgar culture plates. RESULTS: All Gram-negative bacteria tested were identified correctly by MALDI-ToF MS compared to conventional methods, regardless of the preparation method. However, more Gram-positive bacteria were identified when the serum separator tube method was used (83.3%) compared with the differential centrifugation method (65.3  %). Moreover, the serum separator tube protocol requires 12-15 min, while the differential centrifugation protocol requires 30-45 min. CONCLUSIONS: Sample preparation using the serum separator tube method is easy to perform, fast and reliable for accurate microbial identification by MALDI-ToF MS technology.

[Incidence and risk factors of diarrheal diseases among 3-5 year old Israeli Arab children attending kindergartens].

BACKGROUND: The existing limited data on diarrheal diseases in Israel indicate higher rates and more severe illness among Arab children compared to Jewish children. OBJECTIVES: To determine the incidence and risk factors of diarrheal diseases in 3-5 year old Israeli Arab children from villages of Northern Israel. METHODS: We carried out a follow-up study in 343 children who attended 9 kindergartens from 3 villages of Northern Israel. Daily surveillance was conducted on children's absenteeism from the kindergartens. The causes of absenteeism were recorded based on information received from parents' interviews. During the summer vacation, the follow-up was based on biweekly interviews. We also performed a nested case control study to identify potential risk factors of diarrheal disease; data were obtained through mothers' interviews. RESULTS: During the follow-up period, 100 new episodes of diarrhea were recorded yielding an incidence rate of 0.51 episodes/12 child-months, while 55% of the episodes were associated with visits to the clinic. In the multivariate analysis, the risk of diarrheal diseases was increased in males (OR 2.31 95% CI 1.3-4), in children aged 4 years or less compared to older children (OR 1.76 95% CI 1.01-3.06), and when the mother's education was 8 years or less (OR 1.88, 95% CI 1.08-3.26). Having siblings younger than 5 years old was associated with a reduced risk of diarrheal diseases (OR 0.57 95% CI 0.3-0.9). CONCLUSIONS: The incidence rate of diarrheal diseases among Israeli Arab toddlers attending kindergartens in villages from northern Israel is high. The risk factors of diarrheal disease in this population are significantly associated with features of the child and his family rather than environmental characteristics of the community or kindergarten.

Rapid identification of Mycobacterium species by lectin agglutination.

The purpose of the present study is to explore the possibility that plant lectins can be used for the development of rapid and inexpensive technique for differentiation of mycobacterial species. The method is based on interaction between mycobacteria and lectins as visualized by agglutination in a microtiter plate. We employed 18 mycobacterium species and determined the minimal lectin concentration (MLC) of 23 different lectins. For some of the bacteria as a high as 1000 microg/ml of one or more lectins were required to induce agglutination, while for other strains as low as 1.95 microg/ml of the lectin were needed. A unique pattern of agglutination was observed for each species over a range of 62-1000 microg/ml lectin concentrations. There were little or no variations in MLC within strains (intraspecies) of each of two species tested. In contrast, there were marked interspecies variations in MLC. Analysis of the MLC showed that the highest score of interspecies differences with 23 lectins was obtained at 125 microg/ml lectin concentration. At this concentration it was found that the pattern of agglutinations with only two lectins was sufficient to differentiate mycobacterium species from each other. Because the bacteria-lectin interaction is adaptable to various methods of visualization, our findings may set the stage for developing a rapid and reliable tool to differentiate mycobacterium species.

Evaluation of a urine-based enzyme-linked immunosorbent assay test for the detection of Helicobacter pylori infection among 3- to 5-year-old Israeli Arab healthy children.

We conducted a community-based study among 159 healthy Israeli Arab children aged 3 to 5 years old to examine the validity of the HpELISA kit (URINELISA, Otuska Phamaceuticals Co, Ltd, Tokyo, Japan) for detection Helicobacter pylori IgG antibodies in urine. The polyclonal H. pylori stool antigen test (Premier HpSA) served as the gold standard. The sensitivity, specificity, positive and negative predictive values of the URINELISA kit were 34.2%, 96.3%, 90% and 60%, respectively. Using a cutoff value calculated based on the receiver operating characteristic curve (0.066), the corresponding figures were 65.8%, 87.5%, 83% and 72%, respectively. These data indicate that the usefulness of the URINELISA test in epidemiological studies in healthy young children is limited.

Susceptibility of Helicobacter pylori isolates to the antiadhesion activity of a high-molecular-weight constituent of cranberry.

The sensitivity of a large number of antibiotic-resistant and nonresistant Helicobacter pylori isolates to the antiadhesion effect of a high-molecular-mass, nondialysable constituent of cranberry juice was tested. Confluent monolayers of gastric cell line in microtiter plate wells were exposed to bacterial suspensions prepared from 83 H. pylori isolates from antibiotic-treated and untreated patients in the presence and absence of the cranberry constituent. Urease assay was used to calculate the percentage of adhesion inhibition. In two thirds of the isolates, adhesion to the gastric cells was inhibited by 0.2 mg/mL of the nondialysable material. There was no relationship between the antiadhesion effect of the cranberry material and metronidazole resistance in isolates from either treated or untreated patients (N=35). Only 13 isolates (16%) were resistant to both the nondialysable material and metronidazole, and 30 (36%) were resistant to the nondialysable material alone. There was no cross-resistance to the nondialysable material and metronidazole. These data suggest that a combination of antibiotics and a cranberry preparation may improve H. pylori eradication.

The changing pattern of consanguinity in a selected region of the Israeli Arab community.

The prevalence of consanguinity within the Israeli Arab community is relatively high, and is associated with high rates of inherited disorders that lead to a high frequency of morbidity and mortality. Data on consanguinity between couples were recorded during two periods (1980-1985 and 2000-2004) in relation to socioeconomic status of 4 selected villages. Two of the villages (A and B) are known to have high socioeconomic status, and the other two (C and D) are known to have low socioeconomic status. The average incidence of consanguineous marriages has slightly decreased from 33.1% in the first period to 25.9% in the second period (P = 0.0218) in all of the 4 villages. Marriages between first cousins showed a more significant decrease, from 23.9% in the first period to 13.6% in the second period (P < 0.0001). The average consanguinity rates of villages A and B were found to decrease from 22.3 to 16.2% respectively (P < 0.001) between the two observation periods, whereas those of villages C and D were found to decrease from 42.3 to 37.2%, (P < 0.001) during the same two periods. Thus, there has been a change in the pattern of consanguinity within the selected Israeli Arab villages, between the two study periods. This change seems to correlate with the sociodemographic status of the villages. Therefore, improving the socioeconomic status of the villages, as well as implementation of proper health education programs, is expected to have a positive effect in reducing consanguinity.

Is in vitro antibiotic combination more effective than single-drug therapy against anthrax?

Antibiotic combinations are used to enhance antibacterial efficacy and to prevent the development of resistance. We have tested a possible synergistic effect of several antibacterial combinations on Bacillus anthracis. The in vitro activities of antibiotic combinations against two strains of B. anthracis, strain Sterne and the Russian anthrax vaccine strain STi, were tested by the fractional inhibitory concentration (FIC) method, derived from the MICs of the agents in combination, and by measuring the rate of bacterial killing over time by several antibiotic combinations. The FIC results showed that synergism against both B. anthracis strains was observed only with the combination of rifampin and clindamycin. The telithromycin-amoxicillin combination showed synergism against strain Sterne only. All other combinations were either indifferent or antagonistic. The results of the bacterial time-kill study demonstrated indifferent effects for all combinations. These in vitro results demonstrate the difficulties in obtaining synergistic combinations of antibiotics against B. anthracis.

Hemagglutinin of unusual specificity from Helcococcus kunzii.

Helcococcus kunzii is a gram-positive, catalase-negative opportunist. The organism has been isolated from the lower extremities and breast masses of several patients. A clinical isolate of Helcococcus kunzii was shown to possess a hemagglutinin-lectin with a specificity for N-acetylglucosamine and lactose, two structurally unrelated carbohydrates. The lectin is sensitive to protease, heat and mutanolysin. Electron microscopy failed to reveal fimbriae or fibrillae, suggesting that the lectin is associated with peptidoglycan or the cytoplasmic membrane. It is likely that the lectin is involved in adhesion and colonization of H. kunzii.

Type II topoisomerase mutations in Bacillus anthracis associated with high-level fluoroquinolone resistance.

OBJECTIVES: To identify and characterize the mechanisms of high-level fluoroquinolone resistance in two strains of Bacillus anthracis following serial passage in increasing concentrations of fluoroquinolones. METHODS: Fluoroquinolone-resistant isolates of the Sterne and Russian Anthrax Vaccine STi strains were obtained following serial passage in the presence of increasing concentrations of four different fluoroquinolones. The quinolone-resistance-determining regions of the type II topoisomerase genes from the resistant strains were amplified by PCR and characterized by DNA sequence analysis. The MICs in the presence and absence of reserpine were determined using broth microdilution as a means of detecting active efflux. RESULTS: Single and double amino acid substitutions in the GyrA (Ser-85-Leu; Glu-89-Arg/Gly/Lys) and GrlA (Ser-81-Tyr; Val-96-Ala; Asn-70-Lys) were most common. A single amino acid substitution in GyrB (Asp-430-Asn) was also identified. Efflux only applied to isolates selected for by either levofloxacin or ofloxacin. CONCLUSIONS: Specific amino acid substitutions in the type II topoisomerase enzymes significantly contributed to the development of high-level fluoroquinolone resistance in B. anthracis. However, notable differences between the strains and the drugs tested were identified including the role of efflux and the numbers and types of mutations identified.