Detection of influenza virus in air samples of patient rooms.

BACKGROUND: Understanding the transmission and dispersal of influenza virus and respiratory syncytial virus (RSV) via aerosols is essential for the development of preventative measures in hospital environments and healthcare facilities. METHODS: During the 2017-2018 influenza season, patients with confirmed influenza or RSV infections were enrolled. Room air samples were collected close (0.30 m) to and distant (2.20 m) from patients' heads. Real-time polymerase chain reaction was used to detect and quantify viral particles in the air samples. The plaque assay was used to determine the infectiousness of the detected viruses. FINDINGS: Fifty-one air samples were collected from the rooms of 29 patients with laboratory-confirmed influenza; 51% of the samples tested positive for influenza A virus (IAV). Among the IAV-positive patients, 65% were emitters (had at least one positive air sample), reflecting a higher risk of nosocomial transmission compared with non-emitters. The majority (61.5%) of the IAV-positive air samples were collected 0.3 m from a patient's head, while the remaining IAV-positive air samples were collected 2.2 m from a patient's head. The positivity rate of IAV in air samples was influenced by distance from the patient's head and day of sample collection after hospital admission. Only three patients with RSV infection were recruited and none of them were emitters. CONCLUSION: Influenza virus can be aerosolized beyond 1 m in patient rooms, which is the distance considered to be safe by infection control practices. Further investigations are needed to determine the extent of infectivity of aerosolized virus particles.

Characterization of influenza outbreaks in Lebanon during the 2013/14 and 2014/15 seasons.

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A(H3N2) was dominant in the 2013/14 season while the A(H1N1)pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors (oseltamivir, zanamivir, peramivir and laninamivir). Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region.

Underlying mechanisms of carbapenem resistance in extended-spectrum ß-lactamase-producing Klebsiella pneumoniae and Escherichia coli isolates at a tertiary care centre in Lebanon: role of OXA-48 and NDM-1 carbapenemases.

A recent increase in carbapenem resistance among extended-spectrum ß-lactamase (ESBL)-producing Klebsiella pneumoniae and Escherichia coli isolates at a major tertiary care centre in Lebanon prompted the initiation of this study. Consecutive ESBL-producing isolates were tested for resistance to carbapenems, with initial screening by disk diffusion and Etest using ertapenem. The modified Hodge test was also performed. PCR of ß-lactamase-encoding genes, including bla(NDM-1), bla(KPC), bla(OXA-48), bla(CTX-M), bla(TEM), bla(SHV), bla(CMY-2) and bla(OXA-1), as well as outer membrane porin genes (ompC and ompF) was performed. Sequencing, efflux pump inhibitor tests and random amplified polymorphic DNA (RAPD) analysis were performed. In total, 14 (2.45%) of 572 K. pneumoniae and 24 (1.07%) of 2243 E. coli were ertapenem-non-susceptible [minimum inhibitory concentration (MIC) ≥0.25 µg/mL]. Resistance to other carbapenems was variable. PCR and sequencing analysis revealed that isolates harboured different ß-lactamase genes, including bla(OXA-1), bla(CTX-M-15), bla(TEM-1), bla(CMY-2), bla(OXA-48) and bla(NDM-1). In addition, K. pneumoniae lacked the outer membrane porin-encoding genes, whilst E. coli harboured them with detected mutations. CTX-M-15 was carried on a 90 kb plasmid, whilst OXA-48 was carried on a 70 kb plasmid. Efflux pump inhibition significantly decreased MICs in E. coli. RAPD analysis demonstrated genomic variability. In conclusion, carbapenem resistance in ESBL-producing K. pneumoniae and E. coli is due to the combined effect of ß-lactamases with porin impermeability and/or efflux pump activity observed in these organisms, and in a number of isolates is due to the production of the carbapenemase-encoding genes bla(OXA-48) and the newly emerging bla(NDM-1).

Influenza virus infections in Lebanese children in the 2007-2008 season.

We conducted the first epidemiological study of influenza in Lebanon, a temperate country in the Middle East. Between January to May 2008, 39 patients with influenza-like illness were tested. Of these, 51% contracted influenza in January alone, while no influenza cases were detected in May. Among the 39 patients, 11 influenza A and 4 influenza B cases were detected by rapid kit in addition to 10 respiratory syncytial virus cases by real-time PCR. The influenza viruses were genetically divergent from the 2007/2008 season's vaccine strains, but resembled strains circulating in other countries during the same season.

First detection and sequence analysis of the bla-CTX-M-15 gene in Lebanese isolates of extended-spectrum-beta-lactamase-producing Shigella sonnei.

The emergence in Shigella species of extended-spectrum beta-lactamases (ESBL) that impart resistance to third-generation cephalosporins is a growing concern world-wide. So far, however, ESBL-producing Shigella have only been reported seven times, albeit from seven different countries. In Lebanon, three ESBL-producing clinical isolates of S. sonnei were recovered from 30 cases of shigellosis diagnosed between July 2004 and October 2005. All three were found to be resistant to amoxycillin, cefotaxime, ceftazidime, aztreonam, trimethoprim/sulphamethoxazole, gentamicin, and kanamycin. Each harboured the bla-CTX-M gene, and the results of sequence analysis indicated this to be of the bla-CTX-M-15 type and encoded on a 70-kb plasmid, flanked by an insertion element (ISEcp1). The bla-TEM-1 gene was also detected on the chromosomes of two of the ESBL-producing isolates. Class-2 integrons containing dhfr1, aadA1 and sat1 genes were detected on the chromosomes of all three isolates but not on the plasmids. Fluoroquinolone-modifying factors [QnrA, QnrB, QnrS or AAC(6')-Ib-cr] were not detected. The results of RAPD analysis, combined with data on antimicrobial susceptibility, indicated that each isolate was unique. In conclusion, the emergence of ESBL-producing isolates of S. sonnei has been demonstrated for the first time in Lebanon. The resistance of these isolates to third-generation cephalosporins was mediated by the CTX-M-15 enzyme, which was plasmid-encoded.

N-(4-hydroxyphenyl)retinamide induces growth arrest and apoptosis in HTLV-I-transformed cells.

N-(4-hydroxyphenyl)retinamide (HPR) is a synthetic retinoid that inhibits growth and induces apoptosis in many human cell lines. We explored the effects of HPR on human T-cell lymphotropic virus type I (HTLV-I)-positive and HTLV-I-negative malignant T-cell lines, most of which are resistant to all-trans retinoic acid. Clinically achievable concentrations of HPR caused a dramatic inhibition of cell proliferation, G(0)/G(1) arrest, and massive apoptosis in all tested malignant T cells, while no effect was observed on resting or activated normal lymphocytes. Interestingly, HTLV-I-negative cell lines were significantly more sensitive to HPR compared to HTLV-I-positive and Tax-transfected cells. In HTLV-I-negative cells only, HPR-induced apoptosis was associated with ceramide accumulation, sharp decrease in mitochondrial membrane potential, and activation of caspases 8, 9 and 3, and could be partially reverted by the caspase inhibitor z-VAD suggesting that Tax protects infected cells from ceramide accumulation and caspase-mediated apoptosis. In HTLV-I-positive cells, HPR treatment rapidly induced proteasomal-mediated degradation of p21, downregulated cyclin D(1), and upregulated bax protein levels. These findings support a potential therapeutic role for HPR in both HTLV-I-associated adult T-cell leukemia/lymphoma (ATL) and HTLV-I-negative peripheral T-cell lymphomas.

Pseudomonas pericarditis in an immunocompetent newborn: unusual presentation with review of the literature.

Acute purulent pericarditis is a rare entity in the neonatal age group. The most common isolated organisms are Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae. Other organisms, like Pseudomonas aeruginosa, have been seldom implicated with only one case of Pseudomonas pericarditis reported in the neonatal period. The prognosis is often considered very poor in this age group. This article describes Pseudomonas pericarditis in a 1-week-old immunocompetent female newborn who was successfully managed with combined medical and surgical therapy.

Cerebral mycotic aneurysm in a child with Down's syndrome: a unique association.

Mycotic aneurysms are rare complications in patients with infective endocarditis, particularly in the pediatric population. We report a case of mycotic aneurysm of the middle cerebral artery complicating bacterial endocarditis in a child with Down's syndrome. The patient was successfully treated medically without the need for surgical intervention.

Ceramide generation by two distinct pathways in tumor necrosis factor alpha-induced cell death.

Ceramide accumulation in the cell can occur from either hydrolysis of sphingomyelin or by de novo synthesis. In this study, we found that blocking de novo ceramide synthesis significantly inhibits ceramide accumulation and subsequent cell death in response to tumor necrosis factor alpha. When cells were pre-treated with glutathione, a proposed cellular regulator of neutral sphingomyelinase, inhibition of ceramide accumulation at early time points was achieved with attenuation of cell death. Inhibition of both pathways achieved near-complete inhibition of ceramide accumulation and cell death indicating that both pathways of ceramide generation are stimulated. This illustrates the complexity of ceramide generation in cytokine action.

IL-1 activates two phospholipid signaling pathways in intestinal epithelial cells.

OBJECTIVE AND DESIGN: the aim of the study was to decipher the molecular signals involved in IL-I's action on intestinal epithelial cells (IEC). MATERIALS AND METHODS: Mode-K cells, used as a model of IEC, were treated with IL-I, and PLA2 activity and PGE2, ceramide, and cyclooxygenase-2 (COX-2) levels were measured using enzyme-immuno-assay kit, EIA, thin-layer chromatography and western blotting assays respectively. RESULTS: IL-I caused a concentration- and time-dependent increase in PLA2 activity (3-fold increase), in ceramide levels (peak increase = 10.5 +/- 0.9 pmol/nmol phosphate), and in COX-2 and PGE2 levels. PGE2 increase was biphasic with an early peak at 10 min (around 5 ng/mg protein) due to increased PLA2 activity. The later peak (13.1 +/- 1.9 ng/mg protein) at 4 h was due to COX-2 induction. CONCLUSION: In conclusion, these findings demonstrate that IL-I regulates IEC function through two pathways, the PLA2 and the sphingomyelin pathways, both of which are capable of modulating the inflammatory process.

Aspergillus vertebral osteomyelitis in a child with a primary monocyte killing defect: response to GM-CSF therapy.

We report the first case of vertebral aspergillosis in a child with a primary defect in monocyte killing, an extremely rare immunodeficiency The diagnosis of defective monocyte killing was made by an in vitro assay that showed normal killing of Staphylococcus aureus by the patient's neutrophils but impaired killing by his monocytes. Importantly, the extensive granulomatous infection that involved the vertebral column, posterior mediastinum, pleura, and lung was not responsive to aggressive treatment with a combination of liposomal amphotericin B. intralesional amphotericin B. itraconazole, and granulocyte transfusions. Dramatic clinical and radiological improvement was only seen after the addition of granulocyte macrophage-colony stimulating factor (GM-CSF) to his treatment regimen. The use of GM-CSF in the treatment of invasive aspergillosis in immunocompromised patients requires further evaluation.

Arsenic-interferon-alpha-triggered apoptosis in HTLV-I transformed cells is associated with tax down-regulation and reversal of NF-kappa B activation.

Human T-cell lymphotropic virus type I (HTLV-I)-associated adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature activated T cells resistant to conventional chemotherapy. The viral transactivator protein Tax plays a critical role in HTLV-I-induced transformation and apoptosis resistance by inducing I kappa B-alpha degradation, resulting in the activation of the NF-kappa Bpathway. In these HTLV-I-transformed cells, arsenic trioxide (As) and interferon (IFN)-alpha synergize to induce cell cycle arrest and apoptosis. We demonstrate that cell death induction is only partly dependent upon caspase activation and is not associated with modulation of bcl-2, bax, or p53 expression. However, combined As and IFN induce the degradation of Tax, associated with an up-regulation of I kappa B-alpha resulting in a sharp decrease in RelA DNA binding nuclear factor (NF)-kappa B complexes because of the cytoplasmic retention of RelA. Taken the role of Tax in HTLV-I-induced transformation, its down-regulation probably accounts for cell death induction through inactivation of the NF-kappa B pathway. Such specific targeting of the viral oncoprotein by As-IFN treatment, reminiscent of As targeting of promyelocytic leukemia/retinoic acid receptor-alpha in acute promyelocytic leukemia, provides strong rational for combined As-IFN therapy in ATL patients. (Blood. 2000;96:2849-2855)

Paediatric infective endocarditis: 19-year experience at a tertiary care hospital in a developing country.

A retrospective study was undertaken to study children who presented with infective endocarditis (IE) to a university teaching hospital in Beirut, Lebanon, between January 1977 and May 1995. Of 41 patients with IE (24F, 17M), 28 (68%) were diagnosed between 1977 and 1985. Patients' ages ranged from 3 to 18 y (mean age 11.3+/-2.8 y), and 13 patients were <10 y of age. Clinical presentations included: fever (in 88%), heart failure (in 39%), neurologic findings (in 20%) and embolic phenomena (in 22%). Nineteen patients (46%) had underlying congenital heart disease (CHD) with tetralogy of Fallot and pulmonary stenosis being the most common. Sixteen patients (39%) had underlying rheumatic heart disease (RHD). A total of 5 children (12%) with normal cardiac anatomy had IE. One had underlying acquired viral myocarditis with mitral insufficiency. Echocardiography showed vegetations in 60%. Blood cultures were positive in 31 patients (76%). IE occurred in three patients following cardiac surgery. In one patient it occurred within 2 mo of surgery and in the other two it occurred within 6 mo. Streptococcus viridans and Staphylococcus aureus were the two most commonly isolated bacteria. Overall mortality rate was 29% (not statistically significant between patients presenting between 1977-1985 and 1986-1995; p = 0.17). There was no statistically significant difference in mortality among the groups (five in the group with CHD, six with RHD and one with structurally normal heart). This study demonstrates that RHD is an important underlying cause of IE in children in our community. This finding is similar to those in other developing countries and different from those in developed countries. Distribution of pathogens and CHD in our study is comparable to some reports in the literature, except for the higher proportion of patients with underlying pulmonary stenosis. Bacterial endocarditis prophylaxis should be emphasized in patients with RHD or pulmonary stenosis.

Evidence against a direct cytotoxic effect of alpha interferon and zidovudine in HTLV-I associated adult T cell leukemia/lymphoma.

The combination of the anti-viral agents, zidovudine (AZT) and interferon-alpha (IFN), is a potent treatment of HTLV-I-associated adult T cell leukemia/lymphoma (ATL). In this study we investigate the possible mechanism of action of this combination by examining several cellular parameters including cell proliferation, cell cycle distribution and apoptosis. The ATL-derived T cell lines HuT-102 and MT-2 served as models. HTLV-I negative T cell lines (CEM and Jurkat) were used as controls. No significant modification of cell growth was observed except at suprapharmacological doses of AZT and IFN. Moreover, these effects were less pronounced in HTLV-I-infected cell lines compared to control cell lines. AZT and IFN treatment did not induce any significant modification of the expression of bcl-2 and p53. Interestingly no in vitro cytotoxic effect of AZT/IFN combination was observed on fresh leukemic cells derived from an acute ATL patient at diagnosis despite achievement of in vivo complete remission using the same therapy. These results suggest that the therapeutic effect of AZT and IFN is not through a direct cytotoxic effect of these drugs on the leukemic cells.

Rheumatic fever in children: a 15-year experience in a developing country.

Clinical data from 91 patients with rheumatic fever (RF), who were hospitalized at a tertiary hospital in Lebanon between 1980 and 1995, were reviewed retrospectively. Age on hospitalization was 11.1+/-2.9 years (mean +/- SD, range 3-17 years). Nineteen patients were <6 years of age. Manifestations included carditis (93%), arthritis (39%), Sydenham's chorea (2%), erythema marginatum (4%), subcutaneous nodules (1%), fever (62%), arthralgia (55%), and acute congestive heart failure (CHF) on initial presentation (44%). Pericardial effusion occurred in 11%. There was positive family history of RF in 14%. Mitral insufficiency and aortic insufficiency occurred in 67 and 35%, respectively. Both mitral and aortic valves were involved in 30% of cases. Tricuspid insufficiency developed in 3% and pulmonary insufficiency in 1%. Mitral stenosis developed in 19%. Twenty-eight patients underwent surgical intervention: mitral valve repair and commissurotomy in 9/91 (10%), mitral valve replacement in 18/91 (20%), and aortic valve replacement in 9/91 (10%). Overall mortality was 12%: 5 following surgical intervention (3 after mitral valve surgery and 2 after mitral and aortic valve surgery). All patients that died had CHF on initial presentation (p = 0.006). This study includes hospitalized patients with predominant rheumatic heart disease. Initial presentation with CHF is a risk factor for surgical intervention and mortality. A significant high surgical intervention rate is noted that is probably related to the nature of the selected group studied. This study emphasizes the significant morbidity and death in patients with RF and carditis.

Old and new targets of antibacterial therapy.

Currently available antibiotics target bacterial cell wall synthesis, protein synthesis, or DNA replication. Antibiotics that are structurally unrelated sometimes have common targets. Mutations in these common targets frequently give rise to bacteria that are resistant to multiple antibiotics. The impact of these bacteria in clinical situations is increasing whereas development of effective antibiotics for their treatment is not keeping pace. This emerging crisis in clinical care has led to intense efforts in new antibiotic development. Both improvements in currently available classes of antibiotics as well as discovery of completely novel ones are being aggressively sought. In this review, the mechanisms of action of available antibiotics will be discussed with emphasis on newly developed drugs. Also, some of the potential new targets of antibiotic therapy in the future will be highlighted.

Congenital heart disease at a tertiary care center in Lebanon.

OBJECTIVE AND METHODS: To study the epidemiology of congenital heart disease (CHD) at the American University of Beirut-Medical Center, we reviewed the medical records of all cardiac patients seen at our outpatient cardiology clinic (OPD) between 1980 and 1995. The charts of all patients with CHD seen as inpatients and/or outpatients at our center during the year 1995 were also reviewed. A cardiologist evaluated all patients and the diagnosis was confirmed at least by echocardiography. The frequency of CHD was reported among three groups: 1980-1995 OPD groups (Group A); the group with CHD seen during the year 1995 (Group B); and (Group C), a subgroup of group B, included all newborns with CHD born at our hospital during the year 1995. Stillbirth and premature infants with the diagnosis of patent ductus arteriosus were excluded from the study. RESULTS: Group A included 883 patients. 344 patients were evaluated in Group B, with a mean age of 3.8 years. The incidence of CHD was 11.5/1,000 live births at our center. There was a relatively low prevalence of complex lesions (i.e., hypoplastic left heart syndrome, transposition of the great arteries) and a relatively high prevalence of the simpler cardiac malformation (i.e., ventricular and atrial septal defects, pulmonary stenosis) in Groups A and B. CONCLUSION: The relatively low prevalence of complex cardiac lesions in our study is probably related to the age of the studied patients, and reflects the high mortality of these complex lesions in our country early in life. The incidence of CHD of 11.5/1,000 live births at our center is higher than that reported in the literature, with evidence of more frequent ventricular septal defects and pulmonary atresia lesions. This may be related to high rate of consanguinity in our population. This review underscores the need for a national cardiac registry center for children in a developing country like Lebanon. Such a database will allow referral and care of complex cardiac lesions.