Early enteral feeding and nosocomial sepsis in very low birthweight infants

BACKGROUND

The interrelations between early enteral feeding, necrotising enterocolitis (NEC), and nosocomial sepsis (NS) remain unclear.

OBJECTIVE

To evaluate the effect of age at the introduction of enteral feeding on the incidence of NS and NEC in very low birthweight (VLBW< 1500 g) infants.

METHODS

Data were collected on the pattern of enteral feeding and perinatal and neonatal morbidity on all VLBW infants born in one centre during 1995-2001. Enteral feeding was compared between infants with and without NS and/or NEC.

RESULTS

The study sample included 385 infants. Of these, 163 (42%) developed NS and 35 (9%) developed NEC. Enteral feeding was started at a significantly earlier mean (SD) age in infants who did not develop nosocomial sepsis (2.8 (2.6) v 4.8 (3.7) days, p = 0.0001). Enteral feeding was introduced at the same age in babies who did or did not develop NEC (3.1 (2) v 3.7 (3) days, p = 0.28). Over the study period, the mean annual age at the start of enteral feeding fell consistently, and this correlated with the mean annual incidence of NS (r(2) = 0.891, p = 0.007). Multiple logistic regression analysis showed age at start of enteral feeding, respiratory distress syndrome, and birth weight to be the most significant predictors of risk of NS (p = 0.0005, p = 0.024, p = 0.011).

CONCLUSIONS

Early enteral feeding was associated with a reduced risk of NS but no change in the risk of NEC in VLBW infants. These findings support the use of early enteral feeding in this high risk population, but this needs to be confirmed in a large randomised controlled trial.

The effect of prenatal consultation with a neonatologist on human milk feeding in preterm infants

OBJECTIVE

To study the effect of prenatal consultation (PC) with a neonatologist on the incidence and duration of human milk feeding (HMF) in preterm infants.

DESIGN/METHODS

A retrospective matched case-control study was preformed at a perinatal centre. Study infants were preterm infants (23-35 wk) whose mothers had received PC emphasizing the importance of HMF. Control infants were matched by birthweight, gestational age and multiplicity.

RESULTS

Each group included 29 mothers and 46 preterm infants. Mean gestational age was 30.1 +/- 3 wk in both groups. Mean birthweight was 1329 +/- 489 (PC) and 1334 +/- 441 g (control). PC infants received HMF for significantly longer, both in the hospital and after discharge (hospital: PC 37 +/- 34 d vs control 15 +/- 19 d, p = 0.001; discharge PC 60 +/- 57 d vs control 21 +/- 32 d; p = 0.0001). No significant difference in neonatal morbidity was detected between the groups.

CONCLUSIONS

PC is associated with significantly longer HMF in preterm infants, both in hospital and after discharge.

Characterization of Salmonella enterica serotype newport isolated from humans and food animals

Salmonella enterica serotype Newport isolates resistant to at least nine antimicrobials (including extended-spectrum cephalosporins), known as serotype Newport MDR-AmpC isolates, have been rapidly emerging as pathogens in both animals and humans throughout the United States. Resistance to extended-spectrum cephalosporins is associated with clinical failures, including death, in patients with systemic infections. In this study, 87 Salmonella serotype Newport strains were characterized by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing and examined for the presence of class 1 integrons and bla(CMY) genes. Thirty-five PFGE patterns were observed with XbaI, and three of these patterns were indistinguishable among isolates from humans and animals. Fifty-three (60%) Salmonella serotype Newport isolates were identified as serotype Newport MDR-AmpC, including 16 (53%) of 30 human isolates, 27 (93%) of 29 cattle isolates, 7 (70%) of 10 swine isolates, and 3 (30%) of 10 chicken isolates. However, 28 (32%) Salmonella serotype Newport isolates were susceptible to all 16 antimicrobials tested. The bla(CMY) gene was present in all serotype Newport MDR-AmpC isolates. Furthermore, the plasmid-mediated bla(CMY) gene was transferable via conjugation to an Escherichia coli strain. The transconjugant showed the MDR-AmpC resistance profile. Thirty-five (40%) of the isolates possessed class 1 integrons. Sequence analyses of the integrons showed that they contained aadA, which confers resistance to streptomycin, or aadA and dhfr, which confer resistance to trimethoprim-sulfamethoxazole. One integron from a swine isolate contained the sat-1 gene, which encodes resistance to streptothricin, an antimicrobial agent that has never been approved for use in the United States. In conclusion, Salmonella serotype Newport MDR-AmpC was commonly identified among Salmonella serotype Newport isolates recovered from humans and food animals. These findings support the possibility of transmission of this organism to humans through the food chain.

Corynebacterium pseudotuberculosis infection in Israeli dairy cattle

Two forms of Corynebacterium pseudotuberculosis infection in Israeli dairy cattle herds during a survey period of 13 years (1989-2001) are described. The more common form, which was diagnosed in 45 herds, was characterized by ulcerative granulomatous lesions which occurred either sporadically--in 26 herds (with a morbidity rate of up to 5%)--or in an epidemic course in 19 herds. Most (80.6%) of the affected animals were cows; the rest were first-calving cows (16.2%) and heifers (3.2%). The morbidity occurred mostly during the summer months. The ulcerative granulomatous lesions appeared in three clinical forms: cutaneous, mastitic and visceral. Mixed forms were also observed. The morbidity rate was 6.4% and the culling rate reached 16.3% of the affected animals. Most of the strains of C. pseudotuberculosis which were isolated from the abscesses in the cutaneous form of the disease and from milk samples failed to reduce nitrate. A decrease in milk production (6%) and an increase in bulk-milk somatic cell count were noted. Necrotic and ulcerative dermatitis on the heel of the foot occurred in an epidemic course in heifers in only two herds during the winter months, with morbidity rates of 7.5 and 76.2%, respectively. C. pseudotuberculosis isolates from skin lesions and from the soil did reduce nitrate. Clinical, epizootiological and microbiological aspects of the infection are described.

Life-threatening thrombotic thrombocytopenic purpura (TTP) in a patient with sickle cell-hemoglobin C disease

We report a patient with hemoglobin sickle cell-hemoglobin C disease who developed the clinical syndrome of thrombotic thrombocytopenic purpura (TTP) during admission for typical acute pain crisis. The potential for multiorgan involvement secondary to vaso-occlusive crisis complicated the diagnosis and overlapped with the patient's clinical presentation of chronic bone pain and hemolytic anemia. Clinical improvement and normalization of laboratory parameters followed rapidly in response to plasma exchange therapy.

Reduction in multiresistant nosocomial infections in neonates following substitution of ceftazidime with piperacillin/tazobactam in empiric antibiotic therapy

AIM

To evaluate the effect of a change in antibiotic protocol on pathogens that cause neonatal sepsis.

METHODS

Suspected sepsis was treated with amikacin together with ceftazidime in 1995-1998 and piperacillin/tazobactam in 1999-2002.

RESULTS

The annual rate for Klebsiella sepsis fell from 2.5 to 0.45 cases per 1000 admission days (p = 0.0001) between the two periods studied.

CONCLUSION

The change from ceftazidime to piperacillin/tazobactam is associated with a decrease in the incidence of Klebsiella sepsis.

Antimicrobial susceptibility and genetic relatedness of Salmonella serovars isolated from animal-derived dog treats in the USA

OBJECTIVES

The objectives of this study were to determine the potential risk of dog treats in transmitting Salmonella to humans in the USA, and to characterize genetic relatedness and antimicrobial resistance among the isolates.

METHODS

A total of 158 dog treats derived from pig ears and other animal parts were randomly collected nationwide and assayed for the presence of Salmonella. The Salmonella isolates were characterized using serotyping, pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility testing.

RESULTS

Forty-one percent (65/158) of samples were positive for Salmonella. Eighty-four Salmonella isolates, comprising 24 serotypes, were recovered from the 65 positive samples. Fourteen samples were contaminated with more than one Salmonella serotype. PFGE analysis of 78 Salmonella isolates yielded 64 patterns. S. Infantis with PFGE patterns indistinguishable from those of strains identified in Canadian outbreaks in 1999 were recovered in several dog treat products. The majority of Salmonella isolates were susceptible to the antimicrobials tested; however, resistance was observed to tetracycline (26%), streptomycin (23%), sulfamethoxazole (19%), chloramphenicol (8%) and ampicillin (8%). Twenty-eight (36%) Salmonella isolates were resistant to at least one antimicrobial and 10 (13%) isolates displayed resistance to four or more antimicrobials. Two isolates were identified as S. Typhimurium DT104 with the characteristic penta-resistance phenotype (ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline). One S. Brandenburg isolate was resistant to eight antimicrobials. Seven Salmonella isolates also contained class I integrons encoding resistance genes to aminoglycosides, beta-lactam and streptothricin antimicrobials.

CONCLUSIONS

The study indicates that animal-derived dog treats in the USA could be a potential source of animal and human infections with Salmonella, including multidrug-resistant Salmonella strains.

Alexithymia in insulin-dependent diabetes mellitus is related to depression and not to somatic variables or compliance

OBJECTIVES

To assess the prevalence of alexithymia in insulin-dependent diabetic mellitus (IDDM) outpatients. To examine whether alexithymia is associated with diabetic somatic variables, depression, and compliance.

METHOD

Our sample comprised 69 diabetic outpatients followed in a university hospital. We assessed the prevalence of alexithymia (26-item Toronto Alexithymia Scale, TAS-26) and the relationships among alexithymia, depression (13-item Beck Depression Inventory, BDI-13), somatic diabetic variables (glycosylated hemoglobin, number of mild or severe hypoglycemia, somatic complications), and compliance (observer-rater scale completed by diabetologist).

RESULTS

The prevalence of alexithymia in IDDM patients was low (14.4%). Alexithymia and depression, as measured by TAS-26 and BDI-13 scores, respectively, correlated with each other. Alexithymia was not correlated with glycemic control, somatic complications, or compliance.

CONCLUSION

In our sample, alexithymia was related to depression and not to somatic factors or compliance.

Hospital to home: Improving internal medicine residents' understanding of the needs of older persons after a hospital stay

Physicians-in-training discharge many older patients from the hospital, but few have any knowledge of what happens to the patients they send home, of how discharge plans are applied, or of the difficulties patients and their families face. The authors describe a pilot program, Hospital to Home, at the University of Rochester School of Medicine and Dentistry's internal medicine residency program, which uses home visits as an educational tool in geriatrics training. The program was begun in July 2001, and 23 residents have participated. Home visits expose residents in their first-year geriatrics rotation to the elements and outcomes of discharge planning and create a heightened awareness of the needs of older persons recently discharged from the hospital. The home visits are videotaped, and the residents present a videoconference based on the visits, which are attended by internal medicine residents, family medicine residents, and medical students. The authors describe the three-part Hospital to Home program, three vignettes that highlight learning experiences, and the residents' feedback about the experience and the use of audiovisual recording for education.

Periapical health and treatment quality assessment of root-filled teeth in two Canadian populations

AIM

The prevalence of apical periodontitis (AP) and the quality of root fillings and restorations were determined in two Canadian populations differing in avail-ability of endodontists.

METHODOLOGY

Radiographs of first-time university patients aged 25-40 years in Toronto and Saskatoon were examined for missing teeth, presence and standard of root fillings, standard of restoration, and AP according to the Periapical Index. Patients with root-filled teeth were invited for clinical examination and interview to inspect the restorations, and to reveal the providers of endodontic treatment and reasons for extractions of missing teeth. Chi-square and independent t-tests interpreted at the 5% significance level were used to examine associations between the prevalence of AP in root-filled teeth and the standard of the root filling, restoration, and providers of treatment.

RESULTS

Proportion of patients with root-filled teeth was significantly higher (P < 0.001) in Toronto than in Saskatoon (39 and 26%, respectively). Presence of AP about root-filled teeth (44% in Toronto, 51% in Saskatoon) was significantly associated with poor density (OR = 2.7) short (OR = 2.4) and long (OR = 2.8) root fillings, and with poor radiographic quality of the restoration (OR = 1.7) Prevalence of AP did not differ significantly between teeth treated by generalists and endodontists.

CONCLUSIONS

The prevalence of AP in root-filled and untreated teeth was comparable to that reported in previous methodologically compatible studies. The quality of both the root filling and the restoration were found to impact on the periapical health of root-filled teeth, with the impact of the restoration being most critical when the quality of the root filling was adequate.

Characterization of antimicrobial resistance among Escherichia coli O111 isolates of animal and human origin

Fifty isolates of Escherichia coli serogroup O111 recovered from humans and various animal species over a 24-year period (1976-1999) were examined for typical virulence-associated factors and susceptibilities to antimicrobials of human and veterinary significance. Nine H (flagellar) types were identified including nonmotile (n = 24), 32 (n = 12), negative (n = 5), and 56 (n = 3). Thirty-five (70%) isolates possessed at least one Shiga-toxin-producing E. coli (STEC)-associated virulence determinants (eae, stxl, stx2, hlyA) via PCR analysis. Of these 35 isolates, 20 possessed eae, stxl, and hlyA genes, whereas three isolates possessed eae, stxl, stx2, and hylA genes. Multiple antibiotic resistance was observed in 70% of the 50 E. coli O111 isolates. The majority of isolates displayed resistance to streptomycin, sulfamethoxazole, tetracycline, and kanamycin. Bacterial resistance to ampicillin, gentamicin, chloramphenicol, trimethoprim and apramycin was also observed. Integrons were identified in 23 (46%) of the E. coli isolates assayed, with a 1-kb amplicon being most frequently observed. DNA sequencing of these integrons revealed the presence of the aadA gene, encoding resistance to streptomycin. Two integrons of 1.5 and 2 kb contained the aadA2 and either dfrI or dfrXII genes, encoding resistance to streptomycin and trimethoprim, respectively. Integrons were also identified from isolates dating back to 1982. Isolates were further genetically characterized via ribotyping, which identified 15 distinct ribogroups, with 62% of isolates clustering into four major ribogroups. Certain riboprint patterns from different animal species, including humans, were observed in isolates spanning the 24-year collection period, suggesting the dissemination of specialized pathogenic O111 clones.

The Effects of Prenatal Intracranial Infusion of Tetrodotoxin on Naturally Occurring Retinal Ganglion Cell Death and Optic Nerve Ultrastructure

In the developing vertebrate nervous system, cell death is known to play an important role in determining final neuron number. Retinal ganglion cells in the cat's visual system undergo a massive elimination by cell death during the prenatal period between E44 (age of embryo in days) and birth (= E65). We have examined whether neural activity contributes to ganglion cell death by infusing tetrodotoxin (TTX), a blocker of the voltage-sensitive sodium channel. TTX was infused intracranially via osmotic minipumps implanted in utero at E42. The effects of the TTX treatment on ganglion cell death and optic nerve ultrastructure were examined at either E49 or E57 by electron microscopy and quantitative analysis of optic axon number. The numbers of optic nerve axons counted in the optic nerves of animals after either 1 or 2 weeks of TTX treatment were not significantly different from the counts in normal animals at comparable ages: E49 TTX-3.2 x 105; E48 normal-3.3 x 105; E57 TTX-2.1 x 105; E59 normal-2.4 x 105. These results suggest that retinal ganglion cells cannot be rescued from death by blockade of neural activity central to the optic chiasma. However, the ultrastructure of optic nerves following 2 weeks of TTX infusion was quite abnormal. The usual packaging of axons into fascicles by glia was disrupted by the presence of many pale, organelle-poor processes that were about 10 times larger in their cross-sectional areas than axons in either normal or TTX-treated nerves. Examination of these processes in serial transverse or in longitudinal electron microscope (EM) sections of the nerve revealed that they were most likely glial in origin. The ultrastructural organization of the optic nerve following 1 week of TTX treatment was normal, indicating that this effect on glial ultrastructure is either cumulative or delayed in onset. These results suggest that while the conduction of action potentials to the terminals of retinogeniculate axons may not play a significant role in regulating ganglion cell number prenatally, it may affect the normal maturation of optic nerve glia.

A PCR-based method for the detection of Streptococcus agalactiae in milk

Bovine mastitis caused by Streptococcus agalactiae is mainly subclinical and therefore can be diagnosed only in the laboratory. We developed a polymerase chain reaction (PCR)-based method for specific and sensitive detection of S. agalactiae in raw milk. The specificity of the PCR reaction is based on unique S. agalactiae DNA sequences within the 16S subunit of the rRNA genes. Two pairs of sequences were used as positive controls; general streptococci primers, which anneal to conserved areas within the 16S rRNA subunit gene, and primers, which anneal to sequences within bovine mitochondrial DNA. The method of detection includes selective enrichment of S. agalactiae in the milk sample, followed by DNA extraction using a rapid and simple procedure developed for this purpose, and specific PCR reaction with appropriate controls. The method enables the detection of one bacterium in 1 ml of raw milk. The method developed can be easily incorporated as part of routine screening of bulk milk collection tanks for early detection of infected cows in a herd.