Role of Campylobacter jejuni as a placental pathogen

Maternal Infection and Preterm Birth: From Molecular Basis to Clinical Implications

As the leading cause of neonatal morbidity and mortality, preterm birth is recognized as a major public health concern around the world. The purpose of this review is to analyze the connection between infections and premature birth. Spontaneous preterm birth is commonly associated with intrauterine infection/inflammation. The overproduction of prostaglandins caused by the inflammation associated with an infection could lead to uterine contractions, contributing to preterm delivery. Many pathogens, particularly Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Gardnerella vaginalis, Ureaplasma urealyticum, Mycoplasma hominis, Actinomyces, Candida spp., and Streptococcus spp. have been related with premature delivery, chorioamnionitis, and sepsis of the neonate. Further research regarding the prevention of preterm delivery is required in order to develop effective preventive methods with the aim of reducing neonatal morbidity.

Campylobacter jejuni infection associated with miscarriage, a case report and literature review

Campylobacter jejuni is recognized as a cause of miscarriage in animals, but rarely in humans. We describe here a case of spontaneous miscarriage at 12 weeks of gestation associated with Campylobacter jejuni bacteremia following digestive disorders. The patient was treated with azithromycin with good clinical evolution and underwent uterine aspiration during hospitalization. In our review of the literature, we found only 12 other miscarriages due to C. jejuni infections. Clinicians should consider this cause of miscarriage in febrile pregnant women, as the bacterium is resistant to many beta-lactam antibiotics, and macrolides are the first-line treatment.

Towards understanding clinical campylobacter infection and its transmission: time for a different approach?

Campylobacter spp. are among the most commonly diagnosed causes of human infection. Methods for detection of the 29 campylobacter species have mainly focused on cultivation of the thermophilic species. More than 99% of clinical campylobacter isolates notified in the UK in the recent past have been from faecal samples and associated with gastroenteritis. Campylobacter enteritis notifications in temperate zones show a seasonal increase during the summer months with a sharp decrease in the winter months, a pattern which remains incompletely understood. The striking seasonality in the expression of many human genes, some concerned with inflammation and immunity, suggests a need for further study of the host regarding the temporal distribution of many human infections, including campylobacteriosis. A tendency for campylobacter to enter a non-cultivable state under adverse conditions effects a reduction in the number of isolations. A Polymerase Chain Reaction (PCR)-based screening approach for the presence of the Campylobacter genus and followed by speciation has provided some insight into the limitations of cultivation for campylobacter, also allowing the discovery of new species. The increased sensitivity of the PCR-based approach over culture-based methods may make it difficult for the laboratory to differentiate asymptomatic campylobacter carriage from clinical campylobacter infection in non-sterile body sites. Campylobacter infection depends on a combination of host factors, and on acquisition of a suitably virulent strain with a tropism for human epithelium. The possibility of persistence of campylobacter in a viable but non-culturable latent form in the human body may also require further investigation. The scope of this review includes a discussion of current methods for diagnosing acute campylobacter infection and for detecting campylobacter in water and foodstuffs. The review also questions the prevailing view that poultry is the most common source of campylobacteriosis.

Campylobacter-induced Fetal Death in a Rhesus Monkey

A pregnant 4-year-old rhesus monkey ( Macaca mulatta) was presented with a history of acute vaginal bleeding. Physical examination revealed an open cervix. An ultrasound scan demonstrated a viable early third-trimester fetus, approximately 16 weeks of gestational age. Hematology results showed that the monkey was anemic, with a normal leukogram and Döhle bodies. A subsequent cervical culture was positive for Campylobacter fetus. The fetus died 3 days later, and a necropsy of the fetus and placenta was performed. Microscopic examination of the placenta revealed villitis, perivillitis, and deciduitis with S-shaped and gull wing-shaped bacteria. C. fetus was considered the cause of the placental lesions and fetal death; however, the pathogenesis of the infection (hematogenous vs. ascending from the maternal genital tract) was not clear. This is the first report of a Campylobacter-induced fetal death in the rhesus monkey. Because macaques can be asymptomatic carriers and Campylobacter-induced diarrhea is common, this finding has implications for breeding success in nonhuman primate breeding colonies.

Campylobacter jejuni infection during pregnancy: long-term consequences of associated bacteremia, Guillain-Barré syndrome, and reactive arthritist

Campylobacter jejuni infections are the main cause of foodborne gastroenteritis in the United States and other developed countries. Generally, C. jejuni infections are self-limiting and treatment is not necessary; however, infections caused by this organism can lead to potentially dangerous long-term consequences for some individuals. Bacteremia, Guillain-Barré syndrome (GBS; an acute flaccid paralytic disease), and reactive arthritis (ReA) are the most serious of the long-term consequences of C. jejuni infections. During pregnancy, foodborne infections may be hazardous to both the woman and the fetus. C. jejuni-induced bacteremia during pregnancy may lead to intrauterine infection of the fetus, abortion, stillbirth, or early neonatal death. Infection of a newborn by the mother during the birth process or shortly after birth may lead to neonatal enteritis, bacteremia, and/or meningitis. C. jejuni enteritis is the inducing antecedent infection in approximately 30% of cases of GBS. Thus, pregnant women infected with C. jejuni may contract GBS. GBS during pregnancy does not affect fetal or infant development and does not increase spontaneous abortion or fetal death; however, it may induce spontaneous delivery during the third trimester in severe cases. Reactive arthritis occurs in approximately 2% of C. jejuni enteritis cases and leads to the impaired movement of various joints. Pregnant women with C. jejuni-induced reactive arthritis can be expected to deliver a normal infant. A pregnant patient with GBS or ReA may be unable to care for a newborn infant because of the physical impairment induced by these diseases. Since C. jejuni infections put both fetuses and pregnant women at risk, pregnant women must take special care in food handling and preparation to prevent such infections.

Brucellosis in pregnant women

Brucella species occasionally cause spontaneous human abortion, but theories regarding whether they do so more frequently than do other infectious pathogens remain controversial. We reviewed 92 pregnant women who presented with acute brucellosis at a Saudi Arabian hospital. From 1983 through 1995, the cumulative incidence of pregnancy and brucellosis was 1.3 cases per 1000 delivered obstetrical discharges. The incidence of spontaneous abortion in the first and second trimesters was 43%, and the incidence of intrauterine fetal death in the third trimester was 2%. Antepartum antimicrobial therapy with cotrimoxazole or cotrimoxazole/rifampin was protective against spontaneous abortion (relative risk, 0.14; 95% confidence interval, 0.06--0.37; P<.0001). The beneficial effect of treatment occurred in women with febrile illness; vaginal bleeding at presentation usually led to spontaneous abortion. This study demonstrated that the incidence of spontaneous abortion among pregnant women with brucellosis is high and that these women should receive prompt therapy with antimicrobial agents when they present for medical care.

Plasma cytokine response in mice with bacterial infection

BACKGROUND

Exposure to microorganisms elicts the production of cytokines. These soluble factors enhance several innate immune functions and regulate the ensuing specific immune response aimed at limiting the spread of infection.

AIM

This study was undertaken to quantify the plasma levels of pro-inflammatory cytokines during the course of primary Listeria monocytogenes and Campylobacter jejuni infection. Using an in vivo infection the relationship between endogenous cytokines and the bacterial number in the liver of infected animals was examined.

METHODS

C57BL/6 mice were infected by the intraperitoneal route. At different time points we determined the number of colony-forming units of bacteria in the liver of infected animals and paralled these with the plasma levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) measured by enzyme immunoassays.

RESULTS

L. monocytogenes infection lasted 10-11 days. IFN-gamma production occurred in the early phase but was more pronounced after day 4, following the appearance of specific immunity. The duration of experimental campylobacteriosis was 15 days. Early IFN-gamma production was not significant but a progressive rise of this cytokine in plasma was seen during the second week post infection. Mice produced measurable amounts of plasma TNF-alpha immediately after being given viable L. monocytogenes, peaking on day 2-3 when the greatest number of bacteria was present in the examined organs. During C. jejuni infection plasma TNF-alpha was produced in a similar manner, but the highest concentrations were found a few days later than in listeriosis, in correlation with the different course of campylobacteriosis. The quantity of IL-6 increased and decreased in concordance with clearance of L monocytogenes and the clinical status of the animals. C. jejuni did not promote the induction of this cytokine. This is to some extent an unusual finding. With respect to the role of IL-6 in Th2 responses and antibody production, the appearance of this cytokine in campylobacteriosis was more expected.

DISCUSSION

During systemic bacterial infection, a network of pro-inflammatory cytokines is activated and blood levels of these cytokines are elevated, albeit inconsistently, with large individual variations and depending on microbial characteristics and structure.

In vitro permeation of human chorioamniotic membranes by Campylobacter jejuni

In vitro penetration of human chorioamniotic membranes by Campylobacter jejuni was investigated by an organ culture model. Membrane permeation was detected by an immunoperoxidase technique and viable bacterial counts of membrane homogenates. Human clinical isolates of C. jejuni inoculated on the maternal side of the membranes penetrated to the fetal side suggesting that chorioamniotic membranes constituted a weak barrier against Campylobacter infection. Chicken fecal isolates did not penetrate chorioamniotic membranes. In vitro culture conditions did not affect the viability of membranes. Human placental extracts and amniotic fluids enhanced the in vitro growth of C. jejuni. These results suggest that certain strains of C. jejuni may penetrate intact fetal membranes and this event may play a role in the pathogenesis of infection.