Positive Uterine Cultures Research Articles

Clinical implications of uterine cultures obtained during urgent caesarean section.

Postpartum endometritis (PPE) is 12-25 times more common following caesarean sections (CS) performed after labour onset than after vaginal delivery. Risk factors for PPE include prolonged rupture of membranes (ROM), chorioamnionitis, prolonged labour, multiple cervical examinations and Group B Streptococcus colonisation of the lower genital tract. We compared uterine culture results and microbial antibiotic susceptibility according to ROM duration in emergent intrapartum CS. Secondary outcomes included PPE incidence, and identification of clinical and microbiological predictors of infectious postpartum morbidity. In a retrospective case series of intrapartum CS in which uterine culture was performed, associations with postpartum outcomes including postpartum microbiology are reported. The results were stratified by the duration of ROM (treated as a categorical variable). Univariate analysis was performed. Positive uterine cultures were identified in 15% of emergent CS and correlated with prolonged ROM. Escherichia coli was the sole pathogen isolated in preterm CS; the ampicillin resistance rate was 75%. Among women with positive uterine cultures, rates were increased for postpartum fever, re-admission, PPE and surgical site infection. Cultures obtained from postpartum infections correlated with pathogens isolated from uterine cultures during CS in 46.1% of women. Positive uterine culture was related to umbilical cord pH < 7.1 (P= 0.017). Obtaining routine intrauterine culture during intrapartum CS is of low risk and low cost, and relatively easy to perform. Further research should investigate clinical and health economic impacts of obtaining intrauterine culture during CS, influences on postpartum antibiotic treatment, and maternal and neonatal morbidity.

Intrauterine bacterial growth in elective and non-elective caesarean sections

We assessed intrauterine bacterial growth for elective and non-elective caesarean sections (CSs). Aerobic uterine cultures were obtained from the uterine cavity immediately following placental removal from 1376 patients who underwent CS in one center during one year. About 13.8% (115/832) of elective CS were positive vs. 55.9% (304/544) of non-elective CS (p < .001). Of non-elective CSs, 28.6% (56/196) of those without ruptured membranes (ROM) were positive vs. 71.3% (248/348) with ROM (p < .001). Mean birth weight and 1-minute Apgar scores were significantly lower in women with positive cultures, elective and non-elective, than negative cultures. A higher percentage of women with positive uterine cultures presented with postpartum endometritis (p < .05). Intrauterine bacteria in elective CSs demonstrate that the uterine cavity is not sterile. Non-elective CS, particularly after membrane rupture, is a significant risk factor for positive uterine culture. Positive uterine culture is associated with lower birth weight, lower one-minute Apgar score and postpartum endometritis. Impact statement What is already known on this subject? Postpartum endometritis is a leading cause of postpartum febrile morbidity. Caesarean sections, in particular non-elective cesareans, are an important risk factor for the development of postpartum endometritis. Controversy exists concerning the sterility of the placenta and uterus. The diagnosis of endometritis is based mainly on clinical findings and does not necessitate bacterial isolation from the uterine cavity. Positive culture at caesarean section has been associated with positive postoperative culture and yet, currently, professional organisations do not recommend the routine sampling of intrauterine cultures during caesarean section. What do the results of this study add? Since positive uterine culture rate was higher in non-elective CSs and associated with lower birth weight and 1-minute Apgar score and postoperative endometritis, obtaining uterine culture in those cases might be of clinical value. What are the implications of these findings for clinical practice and/or further research? Obtaining routine intrauterine cultures during non-elective caesarean sections might be useful for detecting significant pathogens and tailoring antibiotic treatment in postpartum endometritis. Further studies are necessary in order to determine the impact of obtaining intrauterine cultures during caesarean sections, particularly non-elective cesareans.

Diagnostic and Treatment Practices of Equine Endometritis-A Questionnaire.

Endometritis is a major cause for impaired fertility in mares. The objectives of this study were to collect information on diagnostic and treatment practices performed by veterinarians and to investigate possible effects of professional experience, caseload, and geographical location on the practitioners' management of endometritis cases. For this purpose, equine practitioners (n = 680) were asked to fill out an online survey (34 questions). The online survey yielded 117 responses by veterinarians practicing in all parts of Germany. Most respondents came from Lower Saxony and managed <20 mares per year. For the diagnosis of chronic infectious endometritis, uterine sampling for microbiological examination was performed manually with a swab by the majority of practitioners whereas only few used the speculum technique. The incidence of antibiotic resistant pathogens was reported to be <5% by almost all respondents. Most practitioners relied on systemic antibiotic treatment with trimethoprim-sulfadiazine. Only occasionally veterinarians used intrauterine antibiotic therapy. Uterine lavages were performed routinely by almost half of the respondents in case of positive uterine cultures, mostly with 0.9% saline solution. Irritant solutions (e.g., iodine, chlorhexidine, kerosene) were used less often. Collection of an endometrial culture after completion of the treatment was common practice. While only a very limited association of the geographical location of practitioner (e.g., on selection of mares for endometrial culture, p < 0.05) was observed, the number of managed mares affected the answers notably (e.g., for use of irritating intrauterine treatment, p < 0.05). The management of persistent breeding induced endometritis (PBIE) was influenced by the number of managed mares (e.g., for use of oxytocin, p < 0.05) and 29.6% of respondents administered antibiotics as part of their PBIE management. In summary, treatment strategies in the field vary considerably and include also non-evidence-based methods, but most German practitioners apply the recommended suitable treatments. Following the guidelines for antibiotic usage, most veterinarians administer antibiotics dependent on endometrial culture results but do not use cytology, low-volume lavage, or biopsy routinely. Antibiotic resistant uterine pathogens are reported to be isolated infrequently and equine practitioners prefer systemic to local antibiotic treatment of endometritis.

Bacterial colonization of the ovarian bursa in dogs with clinically suspected pyometra and in controls

Septic peritonitis occurs relatively commonly in dogs. Secondary septic peritonitis is usually associated with perforation of intestines or infected viscera, such as the uterus in pyometra cases. The aim of this study was to evaluate the bacterial flora in the ovarian bursae of intact bitches as a potential source of contamination. One hundred forty dogs, clinically suspected of pyometra, were prospectively enrolled. The control group consisted of 26 dogs that underwent elective ovariohysterectomies and 18 dogs with mammary gland tumors that were neutered at the time of mastectomy. Bacteriology samples were taken aseptically at the time of surgery from the bursae and the uterus in all dogs. Twenty-two dogs that were clinically suspected of pyometra had sterile uterine content (“mucometra” cases); the remaining 118 had positive uterine cultures (“pyometra” cases) and septic peritoneal fluid was present in 10% of these cases. Of the 118 pyometra cases, 9 had unilateral and 15 had bilateral bacterial colonization of their ovarian bursae. However, the bacteria from the ovarian bursa were similar to those recovered from the uterine pus in only half of the cases. Furthermore, positive bursae were also seen in one mucometra dog (unilateral) and in four control dogs (two unilateral and two bilateral). The data illustrate that the canine ovarian bursa can harbor bacteria. The biological importance of these isolations remains unclear.

BACTERIA AND INFLAMMATORY RESPONSE IN THE UTERUS OF BITCHES AFTER ARTIFICIAL INSEMINATION

The present study aimed to obtain information about the uterine inflammatory response (number of polymorphonuclear neutrophilic granulocytes - PMNs) in bitches after artificial insemination (AI) and identify the uterine microflora present after the following treatments: insemination using semen with extender (n=6), insemination with fresh semen (n=6) and no inseminated (n=6). The percentage of PMNs on the endometrial surface and within histological sections was evaluated together with the presence of aerobic bacteria in the uterine lumen. For endometrial cytology, there was no significative difference on the number of inflammatory cells between bitches not inseminated (3.05 ± 1.74 PMNs) and those inseminated with fresh semen (3.55 ± 1.51 PMNs); There was a significative difference in both groups compared to the inseminated with semen plus extender (7.80 ± 1.67 PMNs) (p&lt;0.05). Histology showed that there was no significative difference on the number of inflammatory cells between bitches not inseminated (87.72 ± 35.2 PMNs) and those inseminated with fresh semen (122.97 ± 43.31 PMNs); however, it was observed differences in both groups compared to those inseminated with semen plus extender (171.94 ± 42.74 PMNs) (p&lt;0.05). Eight animals, randomly distributed in the groups, showed the presence of Staphylococcus sp and Proteus sp., in the microbiological exam. The extender for semen, with Tris, is a potent inducer of uterine inflammation, and positive uterine cultures may be obtained during estrus without inflammation or uterine infection.

Chronic intrauterine infection and inflammation in the preterm rabbit, despite antibiotic therapy

Objective: In a pregnant rabbit model using intracervical inoculation of Escherichia coli with delayed antibiotic therapy, we investigated the rate of positive cultures and histologic inflammation of maternal and fetal compartments and the concentration of tumor necrosis factor-α in the amniotic fluid for up to 5 days. Study Design: New Zealand White rabbits at 70% gestation were inoculated intracervically with 103,4 colony-forming units of E coli per uterine horn. At varying intervals after inoculation (0.5-4.0 hours), antibiotic therapy was initiated with ampicillin-sulbactam. Primary outcomes were positive cultures and histologic inflammation score. Tumor necrosis factor–α levels in the amniotic fluid were determined by bioassay. Results: A total of 60 animals were inoculated with E coli. At the endpoint, uterine cultures were positive more commonly than in the fetus or amniotic fluid (41.8% vs 27.5% vs 17.3%, respectively), which was consistent with an ascending pathway of infection. Inflammation scores were similar in uterus and placenta but lower in fetal lung and absent in fetal brain (2.8 vs 3.1 vs 0.84 vs 0.0, respectively). Comparing the durations of delay in antibiotic administration, we found a significant increase in positive uterine cultures and a significant increase in histologic inflammation score with increasing delay. The proportion of dead pups within a litter was significantly associated with the log of the tumor necrosis factor–α concentration in amniotic fluid and the degree of histologic inflammation in the uterus, but not with amniotic fluid or other culture positivity. Conclusion: The administration of therapeutic doses of antibiotic does not consistently eradicate bacteria from the rabbit uterus nor, more importantly, from the fetus and the amniotic fluid. Obtaining a negative amniotic fluid culture does not exclude either infection in the decidua or the fetus or histologic inflammation with tumor necrosis factor–α elaboration. (Am J Obstet Gynecol 2002;186:234-9.)

Pregnancy Outcome in Swiss‐Webster Mice Infected With Chlamydia trachomatis

Objective: The objective of this study was to observe pregnancy outcomes in mice infected transvaginally with Chlamydia trachomatis. Methods: Pregnant mice were inoculated transvaginally with either C. trachomatis (CT) or sterile calf serum (CON) on pregnancy day 4. Pregnancy outcomes as well as genital tract histology and culture were compared. Statistical analysis was performed using Fisher's exact test and Student's t-test. Results: Twenty-four of 26 CT mice had positive uterine cultures for C. trachomatis. Inflammation occurred in 9 (34.6%) (P = 0.002, 95% confidence interval = 1.7–3.5) and intrauterine fetal demise occurred in 5 (19.2%) (P = 0.05, 95% confidence interval = 1.6–2.9) of CT mice. No mice in the CON group (0/24) had positive uterine cultures, developed inflammation, or experienced intrauterine fetal demise. Conclusions: Lower genital tract chlamydial infection is associated with intrauterine fetal demise in Swiss-Webster mice.

A rabbit model for bacteria-induced preterm pregnancy loss

Bacterial infection has been implicated in premature labor in humans. To elucidate mechanisms and potential intervention strategies, we sought to develop a model of infection-induced pregnancy loss in rabbits. On day 21 (70% of gestation), each uterine horn was inoculated hysteroscopically with 0.2 ml containing saline solution or 106 cfu Escherichia coli or Bacteroides bivius or Fusobacterium necrophorum. Fetal viability was assessed. Animals were sacrificed at various times or as delivery occurred. Serum progesterone and amniotic fluid prostaglandins were measured. Cultures and histologic sections were prepared. Compared with the saline solution group, E. coli and F. necrophorum-inoculated rabits were significantly more likely to deliver (16 of 16 and six of seven with mean times of 31.9 ± 10.7 and 28.3 ± 11.5 hours, respectively for E. coli and F. necrophorum). Positive amniotic fluid cultures for the E. coli group were found in 11 of 12 (92%) and for the F. necrophorum group in three of three cases (100%). Histologic inflammation was seen heavily in both the E. coli and F. necrophorum groups, whereas it was absent in the saline solution group. Inoculation with B. bivius led to a much lower pregnancy loss rate (eight of 32) and less histologic inflammation despite positive uterine cultures in most animals. This model may provide an opportunity to determine mechanisms of clinical or subdinical intraamniotic infection and to test intervention strategies.

Effect of intrauterine plasma infusion in the mare: Histological, bacteriological and cytological findings

The effect of homologous intrauterine plasma infusion in terms of histological, bacteriological and cytological uterine changes was examined in seven mares in the following four trials: Experiment 1 (E1), infusion of 100 ml of plasma following endometrial swab and biopsy (Day 0), and swab and biopsy on Days 1,3 and 7; Experiment 2 (E2), as in E1 but no swab and biopsy on Days 0 and 3; Control 1 (C1), as in E1 but 100 ml of normal saline substituted for plasma; Control 2 (C2), as in E1 but no uterine infusion. The stage of the estrous cycle was not considered. Incidence of acute endometritis on Day 1 was seven of seven mares in E1, five of seven mares in E2, five of six mares in C1 and six of seven mares in C2. Most Day 7 specimens were free of signs of acute endometritis but in several cases secondary bacterial infection of the uterus had occurred. Positive uterine cultures were common in both experimental and control trials; however, most Day 7 cultures were negative. Signs of acute endometritis were generally most severe on Day 1, with pronounced polymorphonuclear cell infiltration of the stratum compactum. It was concluded that plasma has a local inflammatory effect on the mare endometrium comparable to that of normal saline.

Rationale for Treatment of Endometritis in the Dairy Cow

Endometritis is an inflammation of the uterine lining that is commonly initiated at parturition. The degree of its effect on fertility varies with the severity of the inflammation, the time required for resolution of endometrial lesions, and the extent of permanent changes that impair endometrial gland functions and/or alter the uterine and/or oviductal environment. The primary nonspecific organisms associated with endometrial pathology are Corynebacterium pyogenes and the gram-negative anaerobes. The majority of postpartum dairy cows have some degree of endometritis but resolve it by 40 to 50 days post partum. Cows with certain periparturient disorders involving the reproductive tract and/or a defective host immune mechanism may acquire persistent infections that impair subsequent fertility. Not all infertile cows or all cows with positive uterine cultures have endometritis. Cows recovering from C. pyogenes endometritis may require 1 month after clearance of the organism for fertility to be restored. These cows, as well as many cows with slightly delayed uterine involution at 30 days post partum, do not benefit from antimicrobial therapy. The effect of endometritis varies between herds. It is associated with prolongation of calving intervals that can vary from less than 2 weeks to 2 months or more. The cost of days open beyond 80 to 110 days post partum is currently estimated to be $2.00 to $2.25 per day. Evaluation of the bovine genital tract is best conducted by a rectal examination combined with a vaginal speculum examination. Cows selected for therapy for endometritis should meet the strict requirements of a grossly enlarged uterus and a severely abnormal uterine discharge. Induction of estrus is the treatment of choice whenever possible. When antimicrobial therapy is indicated, tetracycline is recommended for intrauterine use during the early postpartum period when mixed bacterial populations are present. Commonly used doses are 2 to 3 gm. For systemic signs of illness, systemic administration of penicillin has been recommended. Twice daily doses of 5000 to 10,000 IU of penicillin per kg may be necessary to maintain therapeutic blood concentrations. Systemic administration of an antimicrobial is necessary to achieve therapeutic concentrations in the oviducts, cervix, and vagina. With chronic endometritis due to C. pyogenes, intrauterine administration of 1 to 1.5 X 10(6) IU of procaine penicillin G has been recommended. Multiple daily treatments are desirable. Milk from treated cows should be tested for penicillin before it is added to bulk tank milk. It still is not clear whether antimicrobial therapy is cost effective.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteriology of the uterus at cesarean section

1.1. In a report from Johns Hopkins Hospital, 44 per cent positive uterine cultures were found without the use of instillations.2.2. In our series, 4.1 per cent positive uterine cultures were obtained with the routine use of acriflavine instillations.3.3. The importance of anaerobic organisms as the chief contaminants is stressed.4.4. With the use of antiseptic instillations the period of time in labor may be greatly prolonged with negative cultures being obtained as late as 107½hours after the onset of labor.5.5. Intra-partum infection may be present on admission and vaginal instillations are too late to be of real value.6.6. Among the patients cultured there was one death which resulted from hemorrhage.7.7. Fifty-two and five-tenths per cent of the patients who had cesarean sections were cultured.8.8. Of the 6 positive cultures, 5 were not elective cases.9.9. Thirty-five cases were not elective and only five of these patients had positive cultures (14 per cent).10.10. Positive cultures can be obtained with membranes intact.11.11. The morbidity in this series was 52.8 per cent.12.12. Three deaths from puerperal infection occurred during the first year of the study.13.13. Instillations should be given prophylactically twice daily on waiting cases and every four hours if in labor.