Vaginal colonization of extended-spectrum beta-lactamase-producing bacteria during pregnancy: An observational study

Antimicrobial Resistance in Maternal Infections During Pregnancy

Background: An imbalance in the vaginal microbiota, often characterized by reduced lactobacilli, paves the way forth for opportunistic bacteria from the gastrointestinal tract. The presence of aerobic bacteria in the genital tract during pregnancy can have negative outcomes on the pregnancy. Peripartum infections, when not adequately managed, can significantly impact maternal and neonatal health. Antimicrobial resistance poses an escalating global health threat, with newborns particularly vulnerable. Methods: This study constitutes a retrospective observational analysis, encompassing all microbial strains isolated from pregnant women admitted to the "Pius Brînzeu" Clinical County Emergency Hospital in Timișoara, Romania for various infectious diseases over one year. We analyzed 274 samples from 246 pregnant women, of which 242 were cervical samples, 23 urine cultures, 3 wound secretions, 3 amniotic fluids, 1 peritoneal cavity fluid, 1 sputum, and 1 hemoculture. Results: In cervical samples, Group B Streptococcus (GBS) was the most prevalent, representing 42.46% of the isolates. E. coli was the second most frequent at 30.16%, followed by K. pneumoniae at 11.9%, S. aureus at 8.73%, C. albicans at 2.78%, and other species at 3.97%. A total of 9.63% of cervical GBS isolates exhibited resistance to penicillin, while 23.36% were identified as multi-drug resistant (MDR). Methicillin-resistant S. aureus (MRSA) and MDR S. aureus strains were identified in 50% and 54.54% of the S. aureus-positive cervical samples, respectively. Conclusions: Recognizing the implications of maternal infection or colonization, especially with antimicrobial resistance bacteria, aids in assessing risks during pregnancy.

Extended-spectrum β-lactamase-producing Enterobacterales infections among infants following vertical colonization in a neonatal intensive care unit

OBJECTIVE

Extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) has become prevalent among neonates. The present study aimed to describe the incidence of ESBL-E colonization among neonates admitted to a NICU and the incidence of subsequent ESBL-E infection among those with ESBL-E colonization.

STUDY DESIGN

Patients admitted to the NICU at Tokyo Metropolitan Children's Medical Center between April 2011 and March 2023 were enrolled. On admission, the subjects were routinely screened for ESBL-E using pharyngeal and rectal swabs, and those colonized with ESBL-E were assessed for the development of an invasive ESBL-E infection during their NICU stay.

RESULTS

ESBL-E was isolated in 105 of the 8247 neonates (1.3%) admitted to the NICU. Among these patients, 12 (11.4%) experienced the development of an invasive ESBL-E infection.

CONCLUSION

Although ESBL-E colonization occurred in only 1.3% of the neonates admitted to the NICU, 11.4% of them experienced the development of an ESBL-E infection.

Maternal Colonization of Extended-Spectrum-β-Lactamase-Producing Enterobacteriaceae in Preterm Rupture of Membranes

OBJECTIVES

Maternal colonization by extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) has risen, and the antimicrobial resistance of ESBL-E is significant. We aimed to evaluate the rates of ESBL-E colonization among women with preterm premature rupture of membranes (PPROM) and of maternal-neonatal vertical transmission. We also aimed to compare obstetrical and neonatal complications among ESBL-E positive versus negative maternal colonization in pregnancies complicated by PPROM.

METHODS

This retrospective study included women with PPROM who were admitted from 2018 to 2022 for expectant management and were screened for ESBL-E recto-vaginal colonization on their admission. Obstetrical and neonatal outcomes were compared between positive and negative ESBL-E pregnancies. Neonatal outcomes were compared between positive and negative ESBL-E neonates.

RESULTS

Of 118 women with PPROM, 27 (23%) had positive ESBL-E cultures. ESBL-E isolates (cultures from the placenta, cord, amnion, or uterus) were more common in colonized versus non-colonized ESBL-E mothers (55.6% vs. 11.0%, P < 0.001). ESBL-E isolates were more common in neonates of mothers with positive versus negative ESBL-E cultures (33.3% vs. 4.2%, P = 0.017). A higher proportion of neonates of ESBL-E positive than ESBL-E negative mothers needed antibiotic treatment in the neonatal intensive care unit. Neonatal ESBL-E colonization at birth was a predictor of longer stays in the neonatal intensive care unit (P = 0.006).

CONCLUSIONS

In women with PPROM, maternal-ESBL-E colonization was a significant risk factor for neonatal colonization and was associated with neonatal morbidity. The high maternal colonization rate in PPROM raises the need for routine maternal ESBL screening. Future studies should establish the ideal empiric antibiotic regimen in the neonatal intensive care unit for neonates born to ESBL-E colonized mothers.

Maternal-Fetal Exposure to Antibiotics: Levels, Mother-to-Child Transmission, and Potential Health Risks

Due to its widespread applications in various fields, antibiotics are continuously released into the environment and ultimately enter the human body through diverse routes. Meanwhile, the unreasonable use of antibiotics can also lead to a series of adverse outcomes. Pregnant women and developing fetuses are more susceptible to the influence of external chemicals than adults. The evaluation of antibiotic exposure levels through questionnaire surveys or prescriptions in medical records and biomonitoring-based data shows that antibiotics are frequently prescribed and used by pregnant women around the world. Antibiotics may be transmitted from mothers to their offspring through different pathways, which then adversely affect the health of offspring. However, there has been no comprehensive review on antibiotic exposure and mother-to-child transmission in pregnant women so far. Herein, we summarized the exposure levels of antibiotics in pregnant women and fetuses, the exposure routes of antibiotics to pregnant women, and related influencing factors. In addition, we scrutinized the potential mechanisms and factors influencing the transfer of antibiotics from mother to fetus through placental transmission, and explored the adverse effects of maternal antibiotic exposure on fetal growth and development, neonatal gut microbiota, and subsequent childhood health. Given the widespread use of antibiotics and the health threats posed by their exposure, it is necessary to comprehensively track antibiotics in pregnant women and fetuses in the future, and more in-depth biological studies are needed to reveal and verify the mechanisms of mother-to-child transmission, which is crucial for accurately quantifying and evaluating fetal health status.

Monocentric observational cohort study to investigate the transmission of third-generation cephalosporin-resistant Enterobacterales in a neonatal intensive care unit in Heidelberg, Germany

Third-generation cephalosporin-resistant Enterobacterales is a major threat for newborns in neonatal intensive care units (NICUs). The route of acquisition in a non-outbreak setting should be investigated to implement adequate infection prevention measures. To identify risk factors for colonization with and to investigate the transmission pattern of third-generation cephalosporin-resistant Enterobacterales in a NICU setting. This monocentric observational cohort study in a tertiary NICU in Heidelberg, Germany, enrolled all hospitalized neonates screened for cephalosporin-resistant Enterobacterales. Data were collected from 1 January 2018 to 31 December 2021. Weekly screening by rectal swabs for colonization with third-generation cephalosporin-resistant Enterobacterales was performed for all newborns until discharge. Whole-genome sequencing was performed for molecular characterization and transmission analysis. In total, 1,287 newborns were enrolled. The median length of stay was 20 (range 1-250) days. Eighy-eight infants (6.8%) were colonized with third-generation cephalosporin-resistant Enterobacterales. Low birth weight [<1500 g (adjusted odds ratio, 5.1; 95% CI 2.2-11.5; P < 0.001)] and longer hospitalization [per 30 days (adjusted odds ratio, 1.7; 95% CI 1.5-2.0; P < 0.001)] were associated with colonization or infection with drug-resistant Enterobacterales in a multivariate analysis. Enterobacter cloacae complex was the most prevalent third-generation cephalosporin-resistant Enterobacterales detected, 64.8% (59 of 91). Whole-genome sequencing, performed for the available 85 of 91 isolates, indicated 12 transmission clusters involving 37 patients. This cohort study suggests that transmissions of third-generation cephalosporin-resistant Enterobacterales in newborns occur frequently in a non-outbreak NICU setting, highlighting the importance of surveillance and preventive measures in this vulnerable patient group. IMPORTANCE Preterm newborns are prone to infections. Therefore, infection prevention should be prioritized in this vulnerable patient group. However, outbreaks involving drug-resistant bacteria, such as third-generation resistant Enterobacterales, are often reported. Our study aims to investigate transmission and risk factors for acquiring third-generation cephalosporin-resistant Enterobacterales in a non-outbreak NICU setting. Our data indicated that premature birth and low birth weight are significant risk factors for colonization/infection with third-generation cephalosporin-resistant Enterobacterales. Furthermore, we could identify putative transmission clusters by whole-genome sequencing, highlighting the importance of preemptive measures to prevent infections in this patient collective.

Maternal Colonization Versus Nosocomial Transmission as the Source of Drug-Resistant Bloodstream Infection in an Indian Neonatal Intensive Care Unit: A Prospective Cohort Study

BACKGROUND

Drug-resistant gram-negative (GN) pathogens are a common cause of neonatal sepsis in low- and middle-income countries. Identifying GN transmission patterns is vital to inform preventive efforts.

METHODS

We conducted a prospective cohort study, 12 October 2018 to 31 October 2019 to describe the association of maternal and environmental GN colonization with bloodstream infection (BSI) among neonates admitted to a neonatal intensive care unit (NICU) in Western India. We assessed rectal and vaginal colonization in pregnant women presenting for delivery and colonization in neonates and the environment using culture-based methods. We also collected data on BSI for all NICU patients, including neonates born to unenrolled mothers. Organism identification, antibiotic susceptibility testing, and next-generation sequencing (NGS) were performed to compare BSI and related colonization isolates.

RESULTS

Among 952 enrolled women who delivered, 257 neonates required NICU admission, and 24 (9.3%) developed BSI. Among mothers of neonates with GN BSI (n = 21), 10 (47.7%) had rectal, 5 (23.8%) had vaginal, and 10 (47.7%) had no colonization with resistant GN organisms. No maternal isolates matched the species and resistance pattern of associated neonatal BSI isolates. Thirty GN BSI were observed among neonates born to unenrolled mothers. Among 37 of 51 BSI with available NGS data, 21 (57%) showed a single nucleotide polymorphism distance of ≤5 to another BSI isolate.

CONCLUSIONS

Prospective assessment of maternal GN colonization did not demonstrate linkage to neonatal BSI. Organism-relatedness among neonates with BSI suggests nosocomial spread, highlighting the importance of NICU infection prevention and control practices to reduce GN BSI.

Growing threat of extended-spectrum β-lactamase-producing Enterobacteriaceae colonisation in high-risk pregnancies: A cross-sectional study

OBJECTIVE

To investigate the epidemiological changes in extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) vaginal colonisation in pregnant women deemed at high risk, and to identify independent risk factors. Further, the differences in perinatal outcomes according to maternal ESBL-E vaginal colonisation were analysed.

DESIGN

Cross-sectional study.

SETTING

Republic of Korea.

POPULATION

A cohort of 1460 women admitted to our high-risk pregnancy unit between 14⁺⁰ and 36⁺⁶  weeks of gestation.

METHODS

The trend of changes in the association of ESBL-E vaginal colonisation from January 2010 to December 2020 was analysed. The main outcomes were analysed over the study period and ESBL-E vaginal colonisation.

MAIN OUTCOME MEASURES

Rate of ESBL-E vaginal colonisation, risk factors for ESBL-E vaginal colonisation and perinatal outcomes.

RESULTS

The ESBL-E vaginal colonisation rate has tended to increase over the past 11 years, which was attributed to a significantly higher proportion of ESBL-producing Escherichia coli. Cerclage (RR 3.7, 95% CI 2.19-6.40) and prior antibiotic treatment (RR 4.0, 95% CI 2.44-6.54) were found as independent risk factors for ESBL-E vaginal colonisation. Earlier gestational age at delivery and higher proven early-onset neonatal sepsis (EONS) rate were observed in the ESBL-E-positive group.

CONCLUSIONS

The ESBL-E vaginal colonisation rate in pregnant patients at high risk has increased over the past decade, and the independent risk factors for colonisation are cerclage and prior antibiotic treatment. Additionally, maternal ESBL-E vaginal colonisation is associated with higher rates of proven EONS.

Cumulative Antibiogram: A Rapid Method to Hinder Transmission of Resistant Bacteria to Oral Cavity of Newborn Babies

BACKGROUND

A rapid bacterial diagnostic is needed more and more in the treatment of patients, because of the emergence of antibiotic resistance. The cumulative antibiogram, an annual report that monitors antimicrobial resistance trends in health care facilities, may provide a profile of empirical therapy useful in diverse emergency situations, such as transmission of resistant bacteria to oral cavity of newborn babies. We aimed to draw a profile of antibiotic resistance encountered.

METHODS

We assessed the antibiotic resistance (ABR) profile in childbearing women and newborn babies in Ploiesti Obstetrics and Gynecology Hospital by the disk diffusion method characterizing the multidrug-resistant organisms after isolation and identification by phenotypic tests. Extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E), Carbapenem-resistant Enterobacterales (CRE), vancomycin-resistant Enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant Group B Streptococcus (VR-GBS) were detected.

RESULTS

The prevalence of antibiotic resistance was 11.32% (53/468), while the prevalence of the ESBL-E, MRSA, VRE and VR-GBS strains was 8.34% (39/468). Within the bacteria isolated from fifty-three childbearing women, the prevalence of ESBL-E, MRSA, VRE and VR-GBS was 22.64% (12/53), 32.08% (17/53), 11.32% (6/53) and 7.55% (4/53). In the whole studied group, the prevalence was 2.56% (12/468), 3.63% (17/468), 1.28% (6/468) and 0.86% (4/468). Resistant bacteria were detected at birth in the oral cavity of the newborn babies in all cases. Maternal and neonatal isolates shared similar characteristics.

CONCLUSIONS

Cumulative antibiogram is useful in case of empiric treatment needed in diverse emergencies, such as transmission of resistant bacteria to oral cavity of newborn babies.

Prevalence and Antibiotic Resistance Profile of Bacterial Pathogens in Aerobic Vaginitis: A Retrospective Study in Italy

Aerobic vaginitis (AV) is a vaginal infectious condition, characterized by a high inflammatory response and/or signs of epithelial atrophy, a decrease in the amount of Lactobacillus spp. and an increase in enteric origin bacteria. AV, often misdiagnosed, is difficult to treat due to the emerging spread of multi-drug resistant bacterial strains. The present study aimed to define the prevalence of AV, to detect causative bacteria and their antimicrobial resistance pattern. Women 10-95 years old, admitted to San Giovanni di Dio e Ruggi d'Aragona Hospital, Salerno, Italy (in the years 2015-2019) are included in the study. Bacterial identification and antibiotic susceptibility tests were carried out by VITEK^® 2. Among 2069 patients, 1176 tested positive for microbial growth. A higher incidence of infection was found in the 55-64 age group. Among the pathogenic strains, 50.4% were Gram-negative, and 49.6% were Gram-positive. Escherichia coli (E. coli) (32.5%) was the most representative strain, followed by Enterococcus faecalis (E. faecalis) (29.4%), Klebsiella pneumoniae (K. pneumoniae) (7.8%) and Enterococcus faecium (E. faecium) (7.7%). E. coli showed high sensitivity to carbapenems and amikacin. K. pneumoniae carbapenems resistance was fluctuating over time. Alarming resistance to vancomycin was not recorded for Enterococci. Both strains were sensitive to teicoplanin, linezolid and tigecycline. Proper diagnosis and an effective therapeutic approach are needed to improve AV management.

Vancomycin-Resistant Enterococci and Extended-Spectrum β-Lactamase-Producing Bacterial Colonization of the Cervix after Emergency Cerclage: Is It Safe?

Antimicrobial resistance is currently becoming a global threat to human health. We performed a retrospective study on patients who underwent emergency cerclage between January 2016 and December 2018 at the Dongsan Medical Center. Cervical culture was first performed before surgery to confirm that there was no infection and was repeated on days 1, 4, and 7 after surgery. A total of 85 pregnant women underwent emergency cerclage. Among them, six patients had vancomycin-resistant enterococci (VRE) colonization in the cervix after cerclage, and 23 patients developed extended-spectrum β-lactamase (ESBL)-producing bacterial colonization in the cervix. The average gestational age at delivery was lower in the VRE group. Neonatal death was also significantly higher in the VRE group. The rate of occurrence of early-onset sepsis was also higher in the VRE group, and both VRE and ESBL-producing bacterial colonization cases in which early-onset sepsis occurred resulted in neonatal death. The prognosis of cervical VRE colonization after cervical surgery was poor, whereas the prognosis of ESBL-producing bacterial colonization in the cervix did not differ significantly from that of the control group. However, careful neonatal treatment is required considering that early-onset sepsis is fatal to the newborn.

Vertical transfer of antibiotics and antibiotic resistant strains across the mother/baby axis

Antibiotic resistance is a health and socioeconomic crisis recognized as a serious threat affecting humans worldwide. Overuse of antibiotics enhances the spread of multidrug-resistant bacteria, causing drug-resistant infections which can be difficult to treat. This resistance, mostly of the acquired type, is thus a major clinical issue. Acquired resistance can occur by horizontal transfer of genes between bacteria (community settings), by vertical transmission that can occur between mother and her offspring at birth and during lactation, or spontaneously due to antibiotic exposure. While there have been multiple studies about the horizontal transfer of antibiotic-resistance genes, not many studies have been conducted to study their vertical transmission. Vertical transmission is of importance as the early bacterial colonization of infants has an impact on their health and immune programming throughout life. This review discusses some possible mechanisms of mother-to-infant transmission of antibiotics and antibiotic-resistant strains and addresses the knowledge gaps for further studies.

Mother-to-Neonate Transmission of Antibiotic-Resistant Bacteria: A Cross-Sectional Study

We evaluated carriage rates of extended spectrum β-lactam-producing Enterobacterales (ESBL-E), Carbapeneme-resistant Enterobacterales (CRE), vancomycin-resistant Enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA) among pregnant women and determined the maternal-to-neonate transmission rates of these antibiotic-resistant bacteria (ARB). Pregnant women provided rectal and vaginal samples, proximal to delivery. Stool samples were collected from newborns within 48 h of birth. All samples were cultured on selective media for ARB identification. Clinical and demographic data were collected from the participants' medical files. We performed molecular and phenotypic characterization of the different resistance mechanisms, and determined the isolates' antibiotic susceptibility and biofilm-forming ability. The prevalence of ESBL-E, MRSA and VRE among pregnant women were 16%, 6% and 1%, respectively. The prevalence of ESBL-E and MRSA among neonates were 7.6% and 1.6%, respectively. Maternal-to-neonate transmission rates of ESBL-E and MRSA were 48% and 27.8%, respectively. Maternal and neonatal isolates shared similar characteristics. Maternal-to-neonate transmission of ARB plays an important role in bacterial colonization in newborns. Future studies should investigate the outcomes of the high ESBL-E transmission rate. The biofilm-forming ability of ARB was found to affect transmission. Additional factors should be investigated in order to understand the differences between transmitted and non-transmitted bacteria.

HIV infection as a risk factor for vaginal dysbiosis, bacterial vaginosis, and candidosis in pregnancy: A matched case-control study

BACKGROUND

This study aimed to evaluate the vaginal microbiota of HIV-positive pregnant women relative to HIV-negative controls, and to compare their risk of vaginal dysbiosis, bacterial vaginosis, and vulvovaginal candidosis (VVC).

METHODS

This is a nested matched case-control study that analyzed data from women who received pregnancy care at our center from 2003 to 2014. Women routinely underwent screening for asymptomatic vaginal infections using phase microscopy on Gram-stained smears. HIV-positive women were assigned to the case group, and HIV-negative women were assigned to the control group. Cases and controls were matched in a 1:4 ratio. Logistic regression was used to test whether HIV infection was associated with vaginal dysbiosis (Nugent score 4-6), BV (Nugent score 7-10), or VVC.

RESULTS

One hundred and twenty-seven women were assigned to the case group, and 4290 were assigned to the control group (including 508 matched controls). Dysbiosis or BV was found in 29.9% of the cases and 17.6% of the controls. Women in the case group had increased risk of vaginal dysbiosis or BV (odds ratio [OR] 2.09, 95% confidence interval [CI], 1.30-3.32, P = .002). The risk of VVC was also higher in the case group (OR 2.14, 95% CI, 1.22-3.77, P = .008). The incidence of preterm birth did not differ significantly between the groups (cases: 8.7%; controls: 10%, P = .887).

CONCLUSIONS

HIV-positive women are at risk of vaginal dysbiosis, BV, and VVC during pregnancy. As imbalances of the vaginal microbiota can lead to preterm birth, screening and treatment of HIV-positive pregnant women are warranted.