scholarly journals 1164. Acquisition of Methicillin-Susceptible Staphylococcus aureus in the Neonatal Intensive Care Unit: Molecular Comparison of Relatedness of Isolates

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S673-S674
Author(s):  
Dalia F Eid ◽  
Angela Gomez-Simmonds ◽  
Vitaliya Boyar ◽  
Anne-Catrin Uhlemann ◽  
Lorry G Rubin

Abstract Background In the NICU MSSA infections occur frequently and cause morbidity and mortality. Colonization is a risk factor for infection. Optimal infection prevention strategies await a more complete understanding of acquisition and transmission. To investigate possible transmission, we studied whether newly MSSA colonized infants share a strain with another contemporaneously colonized infant. Methods This is a prospective observational study in a level IV NICU from April through November 2019. Infants had weekly MSSA nasal surveillance cultures. Isolates from newly MSSA colonized infants and other infants colonized with MSSA during the same/previous week were subjected to staphylococcal protein A (spa) typing; most pairs with a concordant (CC) spa type were analyzed by whole genome sequencing (WGS; Illumina MiSeq). Pairs of isolates with a CC spa type and < 25 single nucleotide polymorphism differences on WGS were considered closely related (CC pairs). A control group consisted of pairs of isolates from a newly colonized infant with one randomly chosen colonized infant with a discordant (DC) spa type during the same/previous week. The medical records were reviewed for staff member (SM) and room assignment. Fischer’s exact test was used to compare proportions. Results Isolates from 60/68 consecutive newly MSSA colonized infants and 111/133 comparison infants were available for spa typing. Of these 60 infants, 23 (38 %) had a CC spa type with another infant colonized during the same/previous week. Of 18 isolate pairs from infants with a CC spa type that were subjected to WGS, 12 (67%) pairs of isolates were closely related. 7/12 (58 %) of CC pairs had a SM in common compared to 2/13 (15 %) in the DC pair groups, p=0.04. 2/12 (17 %) of CC pairs shared a room compared to 2/13 (15 %) pairs in the DC group, p=1.0. Conclusion Among newly MSSA colonized infants at least 25% are colonized with an isolate closely related to that of another colonized infant indicating likely infant to infant transmission. WGS is more discriminatory than spa typing for MSSA. Given the lack of commonality of room assignment and the commonality of SM assignment, a possible role of healthcare personnel in MSSA transmission should be further investigated. Disclosures Anne-Catrin Uhlemann, MD, PhD, Merck (Grant/Research Support)

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S675-S676
Author(s):  
Lorry G Rubin ◽  
Archana Balamohan ◽  
Angela Gomez-Simmonds ◽  
Vitaliya Boyar ◽  
Alexander Chong ◽  
...  

Abstract Background Staphylococcus aureus is an important pathogen of infants in a neonatal intensive care unit (NICU). Colonization precedes infection and decolonization may prevent infection. The origin of colonizing organisms may be the NICU environment or personnel or visitors. We have observed infants who became recolonized after successful decolonization. The purpose of this study was to determine the proportion of infants who become recolonized with the same strain or a different strain. Methods Eligible infants were consecutive infants who 1. were colonized with methicillin-susceptible S. aureus and were successfully decolonized with topical mupirocin ointment (nares and umbilicus) as evidenced by 2 or more consecutive negative weekly surveillance cultures (in the absence of a course of systemic antibiotics with activity against MSSA), 2. subsequently became recolonized, and 3. the pair of isolates was available for analysis. Isolates were analyzed by staphylococcal protein A (spa) typing and pairs with concordant spa types were subjected to whole genome sequencing (WGS; Illumina MiSeq) and phylogenetic analyses. Pairs of isolates with fewer than 25 single nucleotide polymorphism differences were considered closely related. Results There were 19 occurrences of MSSA recolonization in 17 infants following 2-6 (median, 2) negative weekly intervening surveillance cultures. Based upon spa typing (that identified 19 spa types), in 11 (58%) there was a concordant spa type and in 8 (42%) there was a discordant spa type. Of the 11 pairs of isolates with concordant spa types that were compared after WGS, 10 were closely related resulting overall in recolonization with a closely related strain in 53% of episodes. Conclusion Among MSSA colonized infants who become recolonized after successful decolonization, the recolonizing strain is the same as the original strain in over half of cases. In such cases the source is more likely to be a visitor than the NICU environment or staff. The possibility that some cases classified as recolonization were in fact persistent low level colonization or carriage in another body site not detected by surveillance cultures cannot be excluded. Disclosures Anne-Catrin Uhlemann, MD, PhD, Merck (Grant/Research Support)


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S369-S369
Author(s):  
Alexandra Hill-Ricciuti ◽  
Samantha Ferguson ◽  
Wenjing Geng ◽  
Stephania Stump ◽  
Maria Messina ◽  
...  

Abstract Background In the NICU, MSSA is a more prevalent pathogen than MRSA, but optimal infection prevention and control strategies for MSSA are not yet well understood. There are likely multiple routes of MSSA acquisition given its role as normal flora and its detection in the anovaginal tract of pregnant women. We describe the molecular epidemiology of MSSA in our NICU during a yearlong surveillance effort. Methods Included infants were hospitalized in a university-affiliated level III-IV NICU from January to December 2017 (1032 admissions) and had positive clinical and/or surveillance cultures for MSSA. Infants admitted at ≥7 days of age were screened for MSSA colonization by culturing the anterior nares and three skin sites. All infants in the NICU were screened twice monthly. Spa typing was performed to genetically characterize isolates. Results During the study period, MSSA was identified in 187 infants (18 at admission, 145 by twice monthly surveillance, and 24 from clinical cultures). In all, 269 MSSA isolates (245 surveillance and 24 clinical isolates) from 166 infants were spa typed. Sixty-two MSSA spa types were identified; 31 (50%) were each detected in only one infant. The incidence of the nine most common spa types is shown (Figure 1); t279 (13%), t002 (8%), and t1451 (6%) had the highest incidence. t1451 and t571 belong to ST398, a common MSSA clone in the local community. The epidemiology of spa types varied; e.g., incident cases of t279 was detected in 10 months, t1451 was detected in 6 months and t148 in 3 months. Among the 14 sets of twins and triplets with MSSA isolates, 12 (86%) shared the same spa type as their sibling(s). Of the 58 infants with >1 MSSA isolate, 12 (21%) acquired new spa-types. No spa type(s) predominated in the 19 episodes of invasive infections. In 6 infants with both colonizing and invasive isolates, colonizing and invasive isolates were the same spa type(s) in 5. Conclusion Spa typing demonstrated that MSSA isolates in our NICU exhibited substantial genetic heterogeneity. While these data do not elucidate acquisition route(s), they suggest infants are acquiring MSSA from multiple sources, likely including family members and the local community. Ongoing sequencing studies are examining common spa types to further understand transmission dynamics. Disclosures A. C. Uhlemann, Merck: Investigator, Grant recipient


2017 ◽  
Vol 80 (3) ◽  
pp. 476-481 ◽  
Author(s):  
V. Murugadas ◽  
C. Joseph Toms ◽  
Sara A. Reethu ◽  
K. V. Lalitha

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) has been a global health concern since the 1960s, and isolation of this pathogen from food-producing animals has been increasing. However, little information is available on the prevalence of MRSA and its clonal characteristics in seafood and the aquatic environment. In this study, 267 seafood and aquatic environment samples were collected from three districts of Kerala, India. Staphylococcal protein A (spa) typing and multilocus sequence typing (MLST) was performed for 65 MRSA strains isolated from 20 seafood and aquatic environment samples. The MRSA clonal profiles were t657-ST772, t002-ST5, t334-ST5, t311-ST5, t121-ST8, t186-ST88, t127-ST1, and two non-spa assignable strains. Whole spa gene sequence analysis along with MLST confirmed one strain as t711-ST6 and another as a novel MRSA clone identified for the first time in seafood and the aquatic environment with a t15669 spa type and a new MLST profile of ST420-256-236-66-82-411-477. The MRSA strains were clustered into five clonal complexes based on the goeBURST algorithm, indicating high diversity among MRSA strains in seafood and the aquatic environment. The novel clone formed a separate clonal complex with matches to three loci. This study recommends large-scale spa typing and MLST of MRSA isolates from seafood and the aquatic environment to determine the prevalence of new MRSA clones. This monitoring process can be useful for tracing local spread of MRSA isolates into the seafood production chain in a defined geographical area.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Cristiane Ortigosa Rocha ◽  
Roberto Eduardo Bittar ◽  
Marcelo Zugaib

Objective. To compare neonatal morbidity and mortality between late-preterm intrauterine growth-restricted (IUGR) and appropriate-for-gestational-age (AGA) infants of the comparable gestational ages (GAs).Methods. We retrospectively analyzed neonatal morbidity and mortality of 50 singleton pregnancies involving fetuses with IUGR delivered between 34 and 36 6/7 weeks of GA due to maternal and/or fetal indication. The control group consisted of 36 singleton pregnancies with spontaneous preterm delivery at the same GA, in which the infant was AGA. Categorical data were compared between IUGR and AGA pregnancies by analysis and Fisher's exact test. Ordinal measures were compared using the Kruskal-Wallis test.Results. The length of stay of newborns in the nursery, as well as the need for and duration of hospitalization in the neonatal intensive care unit, was longer in the group with IUGR. Transient tachypnea of the newborn or apnea rates did not differ significantly between the IUGR and AGA groups. IUGR infants were found to be at a higher risk of intraventricular hemorrhage. No respiratory distress syndrome, pulmonary hemorrhage or bronchopulmonary dysplasia was observed in either group. The frequency of sepsis, thrombocytopenia and hyperbilirubinemia was similar in the two groups. Hypoglycemia was more frequent in the IUGR group. No neonatal death was observed.Conclusion. Our study showed that late-preterm IUGR infants present a significantly higher risk of neonatal complications when compared to late-preterm AGA infants.


2019 ◽  
Author(s):  
Wenjing Geng ◽  
Yujie Qi ◽  
Wenting Li ◽  
Thomas H. McConvillle ◽  
Alexandra Hill-Ricciuti ◽  
...  

ABSTRACTPurposeLittle is known about the molecular epidemiology ofStaphylococcus aureusin Chinese neonatal intensive care units (NICUs). We describe the molecular epidemiology ofS. aureusisolated from neonates on admission to Beijing Children’s Hospital.MethodsFrom May 2015-March 2016, nasal swabs were obtained on admission from 536 neonates. Cultures were also obtained from body sites with suspected infections.S. aureusisolates were characterized by staphylococcal chromosomal cassette (SCCmec) type, staphylococcal protein A (spa) type, multilocus sequence type (MLST),sasXgene, antimicrobial susceptibility and cytotoxicity. Logistic regression assessed risk factors for colonization.ResultsOverall, 92 (18%) infants were colonized withS. aureusand 23 (4%) were diagnosed with culture-positiveS. aureusinfection. Of the colonized infants, 72% harbored MSSA, while 74% of infected infants were culture-positive for MRSA. Risk factors for colonization included female sex, age 7-28 days, birthweight and vaginal delivery. The most common MRSA and MSSA clones were community-associated ST59-SCCmecIVa-t437 (60%) and ST188-t189 (15%), respectively. ThesasXgene was not detected. Some MSSA isolates (16%) were penicillin-susceptible and some MRSA isolates (18%) were oxacillin-susceptible. MRSA and MSSA had similar cytotoxicity, but colonizing strains were less cytotoxic than strains associated with infections.ConclusionsS. aureuscolonization was common in infants admitted to our NICU and two community-associated clones predominated. Several non-modifiable risk factors forS. aureuscolonization were identified. These results suggest that screening infants forS. aureusupon admission and targeting decolonization of high-risk infants and/or those colonized with high-risk clones could be useful to prevent transmission.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5204 ◽  
Author(s):  
Funmilola A. Ayeni ◽  
Werner Ruppitsch ◽  
Franz Allerberger

BackgroundStaphylococcus aureusis a human colonizer with high potential for virulence, and the spread of the virulent strains from the colonized hosts to non-carriers in the community is on the increase. However, there are few reports on comprehensive analysis of staphylococcal enterotoxin (SE) genes with clonal lineage inS. aureusin Africa. This is essential because of diversity of cultures and habits of the people. This study analyzed spa types and enterotoxin genes inS. aureusstrains previously isolated from the human nostrils, poultry and clinical samples in Southern Nigeria.MethodsForty-sevenS. aureusisolates were obtained from humans nostrils (n = 13), clinical strains (n = 21) and poultry (n = 13) from previous studies in Southern Nigeria. The strains were analyzed formecAgene, selected toxins genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, ser, seu)and Panton-Valentine leukocidin (PVL) gene(lukS-PV/lukF-PV)by PCR. Population structures of the strains were detected by Staphylococcal protein A (spa) typing.ResultsTwenty different spa types were obtained with the highest percentages, 17% observed inspatype t091 from clinical, nasal and poultry samples while t069 was the most prevalent spa type in poultry. Two MRSA were only detected in human strains. The poultry strains had the highest occurrence of SE genes (18%) followed by nasal strains (15%) and clinical strains (10%). Eighty-nine percent of all tested isolates harbored at least one SE gene;seowas the most prevalent (34%) followed byseg(30%) andsea(21%), whilesec, seeandsejwere absent in all strains. Spa type t355 was associated withlukS-PV/lukF-PVgene and complete absence of all studied SE.Sea, seq, seb, sekwere associated with spa type t069;seawas associated with t127 whilesepwas associated with spa type t091. There were coexistences ofseo/segandsei/seg.ConclusionsThe higher carriage of staphylococci enterotoxin genes by the nasal and poultryS. aureusstrains suggests a high potential of spread of staphylococcal food poisoning through poultry and healthy carriers in the community. This is the first report of high occurrence of staphylococcal enterotoxins genes in poultry from Nigeria.


2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Ehsanollah Ghaznavi-Rad ◽  
Alireza Ekrami

Objectives.Incidence of methicillin-resistantStaphylococcus aureus(MRSA) is increasing every year, especially in burn patients with a high rate of morbidity and mortality. Molecular and epidemiologic studies are useful practices for understanding the relatedness of isolates in a single patient or a hospital. This study aimed at determining molecular characterizations of isolates collected in 2006 and 2014 usingS. aureus-specific staphylococcal protein A (Spa) typing and Multilocus Sequence Typing (MLST) methods.Materials and Methods. Totally, 71 MRSA isolates were collected during the last two studies (2006 and 2014) from burn patients at Taleghani Burn Centre. After confirmation, all isolates were analysed using MLST andSpatyping methods.Results. We reported the emergence of Spa type t021, ST-30-IV MRSA isolates, which were PVL-positive in 14.6% of the cases and t12366, ST-8-IV isolates, which were PVL-negative in 9.8% of the cases. In 2014 study, Spa typing of MRSA isolates revealed five different spa types. Overall, in two studies, t037, ST-239, SCCmecIII, and CC8 were predominant clones and they were reported in 63% of the cases.Conclusion. The predominance of ST-239 in this region during the last eight years is a major concern. It also has a disturbing impact on the management of staphylococcal infections. Moreover, the SCCmectype IV strain is able to disseminate rapidly in hospital environments, demanding an improvement in infection-control policy.


2021 ◽  
Vol 91 (1) ◽  
pp. 1-10
Author(s):  
Tawheed Ahmad Shafi ◽  
◽  
Baljinder K. Bansal ◽  
Shukriti Sharma ◽  
Dhiraj K. Gupta ◽  
...  

The present study was aimed to understand the molecular epidemiology of Staphylococcus aureus (54 isolates), isolated from 422 milk samples obtained from 108 subclinical mastitis affected cows (CMT positive ≥1+ in at least one quarter). The molecular epidemiology of Staphylococcus aureus was studied using coagulase (coa) gene polymorphism, 16S-23S ribosomal spascer (RS-PCR) polymorphism and Staphylococcal protein A (Spa) typing. Staphylococcus aureus produced 7 coagulase genotypes and 8 RS genotypes respectively. Coagulase genotype GTIII (730 bp) was the most prevalent (35 strains) followed by GTV (900 bp, 7 strains) and GTIV (800 bp, 4 strains), whereas RS genotypes GTA accounted for the highest number of strains (31 strains), followed by GTB (11strains), GTH (4 strains) and GTE (3 strains). Coagulase genotype CTIII (730 bp) showed the highest diversity, as isolates within it produced 5 RS genotypes, the majority of them belonging to the RS genotype GTA (29 out of 31 strains). Forty out of 54 Staphylococcus aureus samples isolated in this study were correctly typed by spa typing, and were assigned to 21 known spa types, and one new novel spa type t18462. The study revealed high diversity within Staphylococcus aureus strains, consisting of 7 coagulase genotypes, 8 RS genotypes and 22 spa types.


1978 ◽  
Vol 8 (5) ◽  
pp. 591-597
Author(s):  
M. S. Leffell ◽  
J. D. Folds ◽  
B. Wasilauskas

The use of counterimmunoelectrophoresis (CIE) for detection of serum antibodies to staphylococcal teichoic acids was evaluated against teichoic acids prepared by sonic treatment or lysostaphin extraction of Staphylococcus aureus (Lafferty strain). Of 54 patient sera from suspected cases of staphylococcal endocarditis, osteomyelitis, or septicemia, 33 (61.1%) were positive by CIE analysis; however, 128 of 291 sera (44.0%) from normal adult donors were also positive. Selected CIE-positive sera from patient and control groups were titered by Ouchterlony gel diffusion. In the control group of normal sera, 65% were also positive by gel diffusion, but only 15% had titers of ≥1:2. Of the patient sera, 44.4% had gel diffusion titers of ≥1:2. In addition to the specific teichoic acid band, a second precipitation band could be demonstrated with both patient or normal sera by CIE or gel diffusion. This second precipitin band was shown to involve interactions of test sera with staphylococcal protein A present in the teichoic acid extracts. The protein A precipitins were detected at high concentrations of the antigen extracts, whereas the anti-teichoic acid precipitins were optimally detected at lower antigen concentrations. The formation of protein A precipitin bands did not correlate with the presence of anti-teichoic acid antibodies, as most sera tested were positive for protein A regardless of anti-teichoic acid activity. This study suggests that a high incidence of normal people have levels of antibodies to teichoic acids which are detectable by the highly sensitive, but nonspecific, technique of CIE.


2018 ◽  
Author(s):  
Funmilola Ayeni ◽  
Werner Ruppitsch ◽  
Franz Allerberger

Background. The pathogenic role of S. aureus as causative agent of serious infections and food poisoning is on the increase. However, there are few reports on comprehensive analyses of toxins and staphylococcal enterotoxin (SE) genes in S. aureus in Africa. This study analyzed spa types and toxin genes in S. aureus obtained from our previous studies in Southern Nigeria. Methods. Forty-seven non-duplicate S. aureus isolates were obtained from humans (n = 34) and poultry (n = 13) from previous studies in Southern Nigeria. The strains were analyzed for mecA, selected toxins genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, ser, seu), TSST and lukS-PV/lukF-PV by PCR. Population structures of the strains were detected by Staphylococcal protein A (spa) typing. Results. Twenty three percent of all isolates (47) carried the Panton-Valentine leukocidin (PVl) gene. Two MRSA were detected. Twenty different spa types were obtained, with the highest percentages, 17% belonging to spa type t091 was observed in 4 states from clinical, nasal and poultry samples while t069 is the most prevalent type in poultry. Eighty-nine percent of the all tested isolates harbored at least one staphylococcus enterotoxin. Seo was the most prevalent SE (34%) followed by seg (30%) and sea (21%), while toxic shock syndrome toxin (TSST), seb,sec,,see, sej, sel, sem, and ser, seu were absent in all strains. Spa type t355 was associated with the PVl and complete absence of all studied SE. Sea, seq, seb, sek were associated with spa type 069; t127 was associated with sea while sep was associated with spa type t091. There was coexistence of seo/seg and sei/seg. Conclusions. We detected a high incidence of enterotoxins and PVl encoding genes in these potential staphylococcal reservoir. Specific toxin genes were observed in particular spa types.


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